bombing of hiroshima and nagasaki justified essay

Was the US justified in dropping atomic bombs on Hiroshima and Nagasaki during the Second World War?

For years debate has raged over whether the US was right to drop two atomic bombs on Japan during the final weeks of the Second World War. The first bomb, dropped on the city of Hiroshima on 6 August 1945, resulted in a total death toll of around 140,000. The second, which hit Nagasaki on 9 August, killed around 50,000 people. But was the US justified? We put the question to historians and two HistoryExtra readers...

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America's use of atomic bombs to attack the Japanese cities of Hiroshima and Nagasaki in August 1945 has long remained one of the most controversial decisions of the Second World War . Here, a group of historians offer their views on whether US president Truman was right to authorise these nuclear attacks...

“Yes. Truman had little choice” – Antony Beevor

Few actions in war are morally justifiable. All a commander or political leader can hope to assess is whether a particular course of action is likely to reduce the loss of life. Faced with the Japanese refusal to surrender, President Truman had little choice.

His decision was mainly based on the estimate of half a million Allied casualties likely to be caused by invading the home islands of Japan . There was also the likely death rate from starvation for Allied PoWs and civilians as the war dragged on well into 1946.

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What Truman did not know, and which has only been established quite recently, is that the Imperial Japanese Army could never contemplate surrender, having forced all their men to fight to the death since the start of the war. All civilians were to be mobilised and forced to fight with bamboo spears and satchel charges to act as suicide bombers against Allied tanks. Japanese documents apparently indicate their army was prepared to accept up to 28 million civilian deaths.

Antony Beevor is a bestselling military historian, specialising in the Second World War. His most recent book is Ardennes 1944: Hitler’s Last Gamble (Viking, 2015)

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“no. it was immoral, and unnecessary” – richard overy.

The dropping of the atomic bomb on Hiroshima was justified at the time as being moral – in order to bring about a more rapid victory and prevent the deaths of more Americans. However, it was clearly not moral to use this weapon knowing that it would kill civilians and destroy the urban milieu. And it wasn’t necessary either.

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Militarily Japan was finished (as the Soviet invasion of Manchuria that August showed). Further blockade and urban destruction would have produced a surrender in August or September at the latest, without the need for the costly anticipated invasion or the atomic bomb. As for the second bomb on Nagasaki, that was just as unnecessary as the first one. It was deemed to be needed, partly because it was a different design, and the military (and many civilian scientists) were keen to see if they both worked the same way. There was, in other words, a cynical scientific imperative at work as well.

I should also add that there was a fine line between the atomic bomb and conventional bombing – indeed descriptions of Hamburg or Tokyo after conventional bombing echo the aftermath of Hiroshima. To regard Hiroshima as a moral violation is also to condemn the firebombing campaign, which was deliberately aimed at city centres and completely indiscriminate.

Of course it is easy to say that if I had been in Truman’s shoes, I would not have ordered the two bombings. But it is possible to imagine greater restraint. The British and Americans had planned in detail the gas-bombing of a list of 17 major German cities, but in the end did not carry it out because the moral case seemed to depend on Germany using gas first. Restraint was possible, and, at the very end of the war, perhaps more politically acceptable.

Richard Overy is a professor of history at the University of Exeter and editor of The Oxford Illustrated History of World War Two (OUP, 2015)

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“Yes. It was the least bad option” – Robert James Maddox

The atomic bombs were horrible, but I agree with US secretary of war Henry L Stimson that using them was the “least abhorrent choice”. A bloody invasion and round-the-clock conventional bombing would have led to a far higher death toll and so the atomic weapons actually saved thousands of American and millions of Japanese lives. The bombs were the best means to bring about unconditional surrender, which is what the US leaders wanted. Only this would enable the Allies to occupy Japan and root out the institutions that led to war in the first place.

• Timeline | The countdown to the bombing of Hiroshima

The experience with Germany after the First World War had persuaded them that a mere armistice would constitute a betrayal of future generations if an even larger war occurred 20 years down the line. It is true that the radiation effects of the atomic bomb provided a grisly dividend, which the US leaders did not anticipate. However, even if they had known, I don’t think it would have changed their decision.

Robert James Maddox is author of Hiroshima in History: The Myths of Revisionism (University of Missouri Press, 2007)

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“no. japan would have surrendered anyway” – martin j sherwin.

I believe that it was a mistake and a tragedy that the atomic bombs were used. Those bombings had little to do with the Japanese decision to surrender. The evidence has become overwhelming that it was the entry of the Soviet Union on 8 August into the war against Japan that forced surrender but, understandably, this view is very difficult for Americans to accept.

Of the Japanese leaders, it was the military ones who held out against the civilian leaders who were closest to the emperor, and who wanted to surrender provided the emperor’s safety would be guaranteed. The military’s argument was that Japan could convince the Soviet Union to mediate on its behalf for better surrender terms than unconditional surrender and therefore should continue the war until that was achieved.

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Once the USSR entered the war, the Japanese military not only had no arguments for continuation left, but it also feared the Soviet Union would occupy significant parts of northern Japan.

Truman could have simply waited for the Soviet Union to enter the war but he did not want the USSR to have a claim to participate in the occupation of Japan. Another option (which could have ended the war before August) was to clarify that the emperor would not be held accountable for the war under the policy of unconditional surrender. US secretary of war Stimson recommended this, but secretary of state James Byrnes, who was much closer to Truman, vetoed it.

By dropping the atomic bombs instead, the United States signalled to the world that it considered nuclear weapons to be legitimate weapons of war. Those bombings precipitated the nuclear arms race and they are the source of all nuclear proliferation.

The late Martin J Sherwin was co-author of American Prometheus: The Triumph and Tragedy of J Robert Oppenheimer (Atlantic, 2008)

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“Yes. It saved millions of lives in Japan and Asia” – Richard Frank

Dropping the bombs was morally preferable to any other choices available. One of the biggest problems we have is that we can talk about Dresden and the bombing of Hamburg and we all know what the context is: Nazi Germany and what Nazi Germany did. There’s been a great amnesia in the west with respect to what sort of war Japan conducted across Asia-Pacific. Bear in mind that for every Japanese non-combatant who died during the war, 17 or 18 died across Asia-Pacific. Yet you very seldom find references to this and virtually nothing that vivifies it in the way that the suffering at Hiroshima and Nagasaki has been.

With the original invasion strategy negated by radio intelligence revealing the massive Japanese build-up on the planned Kyushu landing areas, Truman’s alternative was a campaign of blockade and bombardment, which would have killed millions of Japanese, mostly non-combatants. For example, in 1946 the food situation would have become catastrophic and there would have been stupendous civilian deaths. It was only because Japan surrendered when it still had a serviceable administrative system – plus American food aid – that saved the country from famine.

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Another thing to bear in mind is that while just over 200,000 people were killed in total by the atomic bombs, it is estimated that 300,000–500,000 Japanese people (many of whom were civilians) died or disappeared in Soviet captivity. Had the war continued, that number would have been much higher.

Critics talk about changing the demand for unconditional surrender , but the Japanese government had never put forth a set of terms on which they were prepared to end the war prior to Hiroshima. The inner cabinet ruling the country never devised such terms. When foreign minister Shigenori Togo was told that the best terms Japan could obtain were unconditional surrender with the exception of maintaining the imperial system, Togo flatly rejected them in the name of the cabinet.

The fact is that there was no historical record over the past 2,600 years of Japan ever surrendering, nor any examples of a Japanese unit surrendering during the war. This was where the great American fear lay.

Richard B Frank is a military historian whose books include Downfall: The End of the Imperial Japanese Empire (Random House, 1999)

“No. Better options were discarded for political reasons” – Tsuyoshi Hasegawa

Once sympathetic to the argument that the atomic bomb was necessary, the more research I do, the more I am convinced it was one of the gravest war crimes the US has ever committed. I’ve been to Japan and discovered what happened on the ground in 1945 and it was really horrifying. The radiation has affected people who survived the blast for many years and still today thousands of people suffer the effects.

• Read more | “My God, what have we done?” The moral dilemma of Hiroshima

There were possible alternatives that might have ended the war. Truman could have invited Stalin to sign the Potsdam declaration [in which the USA, Britain and Nationalist China demanded Japanese surrender in July 1945]. The authors of the draft of the declaration believed that if the Soviets joined the war at this time it might lead to Japanese surrender but Truman consciously avoided that option, because he and some of his advisors were apprehensive about Soviet entry. I don’t agree with revisionists who say Truman used the bomb to intimidate the Soviet Union but I believe he used it to force Japan to surrender before they were able to enter the war.

The second option was to alter the demand for unconditional surrender. Some influential advisors within the Truman administration were in favour of allowing the Japanese to keep the emperor system to induce so-called moderates within the Japanese government to work for the termination of the war. However, Truman was mindful of American public opinion, which wanted unconditional surrender as revenge against Pearl Harbor and the Japanese atrocities.

Bearing in mind those atrocities, it’s clear that Japan doesn’t have a leg to stand on when it comes to immoral acts in the war. However, one atrocity does not make another one right. I believe this was the most righteous war the Americans have ever been involved in but you still can’t justify using any means to win a just war.

Tsuyoshi Hasegawa is a professor of history at the University of California at Santa Barbara and the author of Racing the Enemy: Stalin, Truman, and the Surrender of Japan (Harvard University, Press 2005)

“Yes. The moral failing was Japan’s” – Michael Kort

Truman’s decision to use the atomic bomb was the best choice available under the circumstances and was therefore morally justifiable. It was clear Japan was unwilling to surrender on terms even remotely acceptable to the US and its allies, and the country was preparing a defence far more formidable than the US had anticipated.

The choice was not, as is frequently argued, between using an atomic bomb against Hiroshima and invading Japan. No one on the Allied side could say with confidence what would bring about a Japanese surrender, as Japan’s situation had been hopeless for a long time. It was hoped that the shock provided by the bombs would convince Tokyo to surrender, but how many would be needed was an open question. After Hiroshima, the Japanese government had three days to respond before Nagasaki but did not do so. Hirohito and some of his advisers knew Japan had to surrender but were not in a position to get the government to accept that conclusion. Key military members of the government argued that it was unlikely that the US could have a second bomb and, even if it did, public pressure would prevent its use. The bombing of Nagasaki demolished these arguments and led directly to the imperial conference that produced Japan’s offer to surrender.

• Read more | The science behind the bombing of Hiroshima

The absolutist moral arguments (such as not harming civilians) made against the atomic bombs would have precluded many other actions essential to victory taken by the Allies during the most destructive war in history. There is no doubt that had the bomb been available sooner, it would have been used against Germany. There was, to be sure, a moral failing in August 1945, but it was on the part of the Japanese government when it refused to surrender after its long war of conquest had been lost.

Michael Kort is professor of social science at Boston University and author of The Columbia Guide to Hiroshima and the Bomb (Columbia Press, 2007)

This article was first published in the August 2015 issue of BBC History Magazine

HistoryExtra readers George Evans-Hulme and Roy Ceustermans debate...

George Evans-Hulme: Yes, it was justified. The US was, like the rest of the world, soldiering on towards the end of a dark period of human history that had seen the single most costly conflict (in terms of life) in history, and they chose to adopt a stance that seemed to limit the amount of casualties in the war, by significantly shortening it with the use of atomic weapons.

It was certainly a reasonable view for the USA to take, since they had suffered the loss of more than 418,000 lives, both military and civilian. To the top rank of the US military the 135,000 death toll was worth it to prevent the “many thousands of American troops [that] would be killed in invading Japan” – a view attributed to the president himself.

This was a grave consequence taken seriously by the US. Ordering the deployment of the atomic bombs was an abhorrent act, but one they were certainly justified in doing.

Roy Ceustermans : No, the US wasn’t justified. Even secretary of war Henry Lewis Stimson was not sure the bombs were needed to reduce the need of an invasion: “Japan had no allies; its navy was almost destroyed; its islands were under a naval blockade; and its cities were undergoing concentrated air attacks.”

The United States still had many industrial resources to use against Japan, and thus it was essentially defeated. Rear Admiral Tocshitane Takata concurred that B-29s “were the greatest single factor in forcing Japan's surrender”, while Prince Konoye already thought Japan was defeated on 14 February 1945 when he met emperor Hirohito.

A combination of thoroughly bombing blockading cities that were economically dependent on foreign sources for food and raw materials, and the threat of Soviet entry in the war, would have been enough.

The recommendations for the use of the bomb show that the military was more interested in its devastating effect than in preparing the invasion. Therefore the destruction of hospitals and schools etc was acceptable to them.

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GEH: The USA was more interested in a quick and easy end to the war than causing untold suffering. They had in their hands a weapon that was capable of bringing the war to a swift end, and so they used it.

The atom bombs achieved their desired effects by causing maximum devastation . Just six days after the Nagasaki bombing, the Emperor’s Gyokuon-hōsō speech was broadcast to the nation, detailing the Japanese surrender. The devastation caused by the bombs sped up the Japanese surrender, which was the best solution for all parties.

If the atomic bombs had not had the devastating effect they had, they would have been utterly pointless. They replaced thousands of US bombing missions that would have been required to achieve the same effect of the two bombs that, individually, had the explosive power of the payload of 2,000 B-29s. This freed up resources that could be utilised for the war effort elsewhere.

RC: After the bloody battles of Iwo Jima and Okinawa , the death toll on both sides was high, and the countries’ negative view of one other became almost unbridgeable, says J Samuel Walker in Prompt and Utter Destruction: Truman and The Use of Atomic Bombs Against Japan . Therefore, the US created unconditional terms of surrender, knowingly going against the Japanese ethic of honour and against the institute of the emperor, whom most Americans probably wanted dead.

Consequently, the use of the atomic bomb became a way to avenge America's fallen soldiers while also keeping the USSR in check in Europe. The Japanese civilian casualties did not matter in this strategy. Also, it did not prevent the Cold War , as the USSR was just a few years behind on a-bomb research.

At the time, revenge, geopolitics and an expensive project that could not be allowed to simply rust away, meant the atomic bomb had to be hastily deployed “in the field” in order to see its power and aftermath – though little was known about radiation and its effects on humans.

GEH: Admittedly, the US did use the atom bomb to keep the USSR in line, and for that it served its purpose. It may not have stopped the Soviets developing their own nuclear device, but that’s not what it was intended for. It was used as a deterrent to keep the (sometimes uneasy) peace between the US and the USSR, and it achieved that. There are no cases of a direct, all-out war between the US and the Soviets that can be attributed to the potentially devastating effects of atomic weaponry.

The atomic bombs certainly established US dominance immediately after the Second World War – the destructive power it possessed meant that it remained uncontested as the world’s greatest power until the Soviets developed their own weapon, four years after the deployment at Nagasaki. It is certainly true that Stalin and the Soviets tried to test US dominance, but even into the 1960s the US generally came out on top.

RC: The price to keep the USSR in check was steep: the use of a weapon of mass destruction that caused around 200,000 deaths (most of them civilians) and massive suffering through radiation . However, it did not stop the USSR from creating the same weapon within four years.

It might be argued that, following the explosions, Japan virtually disappeared from the world stage while the USSR viewed the bombing as an incentive to acquire the same weaponry in order to retaliate in equal force if the atomic bomb was ever used again. Considering the tension between the two countries, a similar attack with tens of thousands of civilian casualties would have created a nuclear apocalypse .

If the US had organised a demonstration, as they had briefly considered, the USSR would still have responded in the same manner, while Japan – which had made clear overtures for a (un)conditional surrender – could have been spared. Furthermore, by postponing the use of the bomb, scientists would have had time to understand the test results, meaning further anguish, like the Bikini Atoll [a huge US hydrogen bomb test in 1954 that had major consequences for the geology and natural environment, and on the health of those who were exposed to radiation] could have been avoided.

GEH: The large civilian death toll that resulted from the bombings can be seen as a small price to pay by the United States in return for their assertion of dominance on the world stage.

The USSR’s development of an atomic weapon had been underway since 1943, and so their quest for nuclear devices cannot be solely attributed to the events of Hiroshima and Nagasaki. It should also be considered that the Soviets’ rapid progress in creating an atom bomb was not exclusively down to their desire to compete with the United States, but from spies passing them US secrets.

Postponing the use of the atom bomb would only have prolonged the war and potentially created an even worse fate for the people of Japan, with an estimated five to 10 million Japanese fatalities – a number higher than some estimates for the entire Soviet military in the Second World War.

Ultimately, the atomic bombs did what they were designed to do. They created such a high level of devastation that the Japanese felt they had no option but to surrender unconditionally to the United States, hence resulting in US victory and the end of the Second World War .

RC: Of course civilian casualties of another nation would have been acceptable to the USA. Japan had made clear overtures to peace, but cultural differences made this nearly impossible (the shame of unconditional surrender goes against their code of honour).

The determination to use an expensive bomb instead of letting it rust away; the desire to find out how devastating it was and the opportunity to use the bomb as a strong showcase of US supremacy, made Japan the ideal target.

Obviously, the USSR would eventually succeed in creating the a-bomb. Therefore, making Hiroshima & Nagasaki the example of the tremendous power of the bombs would make it clear to the USSR that they too needed such weapons to defend themselves.

Moreover, other countries claimed the right of nuclear weapons to defend their citizens. Consequently, the tragic bombings became the example of an arm’s race instead of peace.

Furthermore, since Japan was already on the brink of collapse the bombing was unnecessary, and peace talks would have taken place within a decent time frame (even after the cancelled Hawaii summit). The millions of deaths calculated by Operation Downfall [the codename for the Allied plan for the invasion of Japan near the end of the Second World War, which was abandoned when Japan surrendered following the atomic bombings of Hiroshima and Nagasaki] actually show that only desperation and honour stood between Japan and unconditional surrender.

George Evans-Hulme has a passion for military and political history, and enjoys visiting historical sites across the UK.

Roy Ceustermans has a master's degree in the history of the Catholic Church, an advanced master's degree on the historical expansion, exchange and globalisation of the world, and a master’s degree in management.

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Terrible But Justified: The U.S. A-Bomb Attacks on Hiroshima and Nagasaki

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The Atomic Bomb and the End of World War II

A Collection of Primary Sources

Updated National Security Archive Posting Marks 75th Anniversary of the Atomic Bombings of Japan and the End of World War II

Extensive Compilation of Primary Source Documents Explores Manhattan Project, Eisenhower’s Early Misgivings about First Nuclear Use, Curtis LeMay and the Firebombing of Tokyo, Debates over Japanese Surrender Terms, Atomic Targeting Decisions, and Lagging Awareness of Radiation Effects

Washington, D.C., August 4, 2020 –  To mark the 75th anniversary of the atomic bombings of Hiroshima and Nagasaki in August 1945, the National Security Archive is updating and reposting one of its most popular e-books of the past 25 years. 

While U.S. leaders hailed the bombings at the time and for many years afterwards for bringing the Pacific war to an end and saving untold thousands of American lives, that interpretation has since been seriously challenged.  Moreover, ethical questions have shrouded the bombings which caused terrible human losses and in succeeding decades fed a nuclear arms race with the Soviet Union and now Russia and others.

Three-quarters of a century on, Hiroshima and Nagasaki remain emblematic of the dangers and human costs of warfare, specifically the use of nuclear weapons.  Since these issues will be subjects of hot debate for many more years, the Archive has once again refreshed its compilation of declassified U.S. government documents and translated Japanese records that first appeared on these pages in 2005.

*    *    *    *    *

Introduction

By William Burr

The 75th anniversary of the atomic bombings of Hiroshima and Nagasaki in August 1945 is an occasion for sober reflection. In Japan and elsewhere around the world, each anniversary is observed with great solemnity. The bombings were the first time that nuclear weapons had been detonated in combat operations.  They caused terrible human losses and destruction at the time and more deaths and sickness in the years ahead from the radiation effects. And the U.S. bombings hastened the Soviet Union’s atomic bomb project and have fed a big-power nuclear arms race to this day. Thankfully, nuclear weapons have not been exploded in war since 1945, perhaps owing to the taboo against their use shaped by the dropping of the bombs on Japan. 

Along with the ethical issues involved in the use of atomic and other mass casualty weapons, why the bombs were dropped in the first place has been the subject of sometimes heated debate. As with all events in human history, interpretations vary and readings of primary sources can lead to different conclusions.  Thus, the extent to which the bombings contributed to the end of World War II or the beginning of the Cold War remain live issues.  A significant contested question is whether, under the weight of a U.S. blockade and massive conventional bombing, the Japanese were ready to surrender before the bombs were dropped.  Also still debated is the impact of the Soviet declaration of war and invasion of Manchuria, compared to the atomic bombings, on the Japanese decision to surrender. Counterfactual issues are also disputed, for example whether there were alternatives to the atomic bombings, or would the Japanese have surrendered had a demonstration of the bomb been used to produced shock and awe. Moreover, the role of an invasion of Japan in U.S. planning remains a matter of debate, with some arguing that the bombings spared many thousands of American lives that otherwise would have been lost in an invasion.

Those and other questions will be subjects of discussion well into the indefinite future. Interested readers will continue to absorb the fascinating historical literature on the subject.  Some will want to read declassified primary sources so they can further develop their own thinking about the issues. Toward that end, in 2005, at the time of the 60th anniversary of the bombings, staff at the National Security Archive compiled and scanned a significant number of declassified U.S. government documents to make them more widely available. The documents cover multiple aspects of the bombings and their context.  Also included, to give a wider perspective, were translations of Japanese documents not widely available before.  Since 2005, the collection has been updated. This latest iteration of the collection includes corrections, a few minor revisions, and updated footnotes to take into account recently published secondary literature.

2015 Update

August 4, 2015 – A few months after the atomic bombings of Hiroshima and Nagasaki, General Dwight D.  Eisenhower commented during a social occasion “how he had hoped that the war might have ended without our having to use the atomic bomb.” This virtually unknown evidence from the diary of Robert P. Meiklejohn, an assistant to Ambassador W. Averell Harriman, published for the first time today by the National Security Archive, confirms that the future President Eisenhower had early misgivings about the first use of atomic weapons by the United States. General George C. Marshall is the only high-level official whose contemporaneous (pre-Hiroshima) doubts about using the weapons against cities are on record.

On the 70th anniversary of the bombing of Hiroshima on August 6, 1945, the National Security Archive updates its 2005 publication of the most comprehensive on-line collection of declassified U.S. government documents on the first use of the atomic bomb and the end of the war in the Pacific. This update presents previously unpublished material and translations of difficult-to-find records. Included are documents on the early stages of the U.S. atomic bomb project, Army Air Force General  Curtis LeMay’s report  on the firebombing of Tokyo (March 1945), Secretary of War Henry  Stimson’s requests  for modification of unconditional surrender terms,  Soviet documents  relating to the events, excerpts from the Robert P. Meiklejohn diaries mentioned above, and selections from the diaries of Walter J. Brown, special assistant to Secretary of State James Byrnes.

The original 2005 posting included a wide range of material, including formerly top secret "Magic" summaries of intercepted Japanese communications and the first-ever full translations from the Japanese of accounts of high level meetings and discussions in Tokyo leading to the Emperor’s decision to surrender. Also documented are U.S. decisions to target Japanese cities, pre-Hiroshima petitions by scientists questioning the military use of the A-bomb, proposals for demonstrating the effects of the bomb, debates over whether to modify unconditional surrender terms, reports from the bombing missions of Hiroshima and Nagasaki, and belated top-level awareness of the radiation effects of atomic weapons.

The documents can help readers to make up their own minds about long-standing controversies such as whether the first use of atomic weapons was justified, whether President Harry S. Truman had alternatives to atomic attacks for ending the war, and what the impact of the Soviet declaration of war on Japan was. Since the 1960s, when the declassification of important sources began, historians have engaged in vigorous debate over the bomb and the end of World War II. Drawing on sources at the National Archives and the Library of Congress as well as Japanese materials, this electronic briefing book includes key documents that historians of the events have relied upon to present their findings and advance their interpretations.

The Atomic Bomb and the End of World War II: A Collection of Primary Sources

Seventy years ago this month, the United States dropped atomic bombs on Hiroshima and Nagasaki, the Soviet Union declared war on Japan, and the Japanese government surrendered to the United States and its allies. The nuclear age had truly begun with the first military use of atomic weapons. With the material that follows, the National Security Archive publishes the most comprehensive on-line collection to date of declassified U.S. government documents on the atomic bomb and the end of the war in the Pacific. Besides material from the files of the Manhattan Project, this collection includes formerly “Top Secret Ultra” summaries and translations of Japanese diplomatic cable traffic intercepted under the “Magic” program. Moreover, the collection includes for the first time translations from Japanese sources of high level meetings and discussions in Tokyo, including the conferences when Emperor Hirohito authorized the final decision to surrender. [1]

Ever since the atomic bombs were exploded over Japanese cities, historians, social scientists, journalists, World War II veterans, and ordinary citizens have engaged in intense controversy about the events of August 1945. John Hersey’s  Hiroshima , first published in the New Yorker  in 1946 encouraged unsettled readers to question the bombings while church groups and some commentators, most prominently Norman Cousins, explicitly criticized them. Former Secretary of War Henry Stimson found the criticisms troubling and published an influential justification for the attacks in  Harper’s . [2] During the 1960s the availability of primary sources made historical research and writing possible and the debate became more vigorous. Historians Herbert Feis and Gar Alperovitz raised searching questions about the first use of nuclear weapons and their broader political and diplomatic implications. The controversy, especially the arguments made by Alperovitz and others about “atomic diplomacy” quickly became caught up in heated debates over Cold War “revisionism.” The controversy simmered over the years with major contributions by Martin Sherwin and Barton J. Bernstein but it became explosive during the mid-1990s when curators at the National Air and Space Museum met the wrath of the Air Force Association over a proposed historical exhibit on the Enola Gay. [3] The NASM exhibit was drastically scaled-down but historians and journalist continued to engage in the debate. Alperovitz, Bernstein, and Sherwin made new contributions as did other historians, social scientists, and journalists including Richard B. Frank, Herbert Bix, Sadao Asada, Kai Bird, Robert James Maddox, Sean Malloy, Robert P. Newman, Robert S. Norris, Tsuyoshi Hagesawa, and J. Samuel Walker. [4]

The continued controversy has revolved around the following, among other, questions:

• were the atomic strikes necessary primarily to avert an invasion of Japan in November 1945?
• Did Truman authorize the use of atomic bombs for diplomatic-political reasons-- to intimidate the Soviets--or was his major goal to force Japan to surrender and bring the war to an early end?
• If ending the war quickly was the most important motivation of Truman and his advisers to what extent did they see an “atomic diplomacy” capability as a “bonus”?
• To what extent did subsequent justification for the atomic bomb exaggerate or misuse wartime estimates for U.S. casualties stemming from an invasion of Japan?
• Were there alternatives to the use of the weapons? If there were, what were they and how plausible are they in retrospect? Why were alternatives not pursued?
• How did the U.S. government plan to use the bombs? What concepts did war planners use to select targets? To what extent were senior officials interested in looking at alternatives to urban targets? How familiar was President Truman with the concepts that led target planners chose major cities as targets?
• What did senior officials know about the effects of atomic bombs before they were first used. How much did top officials know about the radiation effects of the weapons?
• Did President Truman make a decision, in a robust sense, to use the bomb or did he inherit a decision that had already been made?
• Were the Japanese ready to surrender before the bombs were dropped? To what extent had Emperor Hirohito prolonged the war unnecessarily by not seizing opportunities for surrender?
• If the United States had been more flexible about the demand for “unconditional surrender” by explicitly or implicitly guaranteeing a constitutional monarchy would Japan have surrendered earlier than it did?
• How decisive was the atomic bombings to the Japanese decision to surrender?
• Was the bombing of Nagasaki unnecessary? To the extent that the atomic bombing was critically important to the Japanese decision to surrender would it have been enough to destroy one city?
• Would the Soviet declaration of war have been enough to compel Tokyo to admit defeat?
• Was the dropping of the atomic bombs morally justifiable?

This compilation will not attempt to answer these questions or use primary sources to stake out positions on any of them. Nor is it an attempt to substitute for the extraordinary rich literature on the atomic bombings and the end of World War II. Nor does it include any of the interviews, documents prepared after the events, and post-World War II correspondence, etc. that participants in the debate have brought to bear in framing their arguments. Originally this collection did not include documents on the origins and development of the Manhattan Project, although this updated posting includes some significant records for context. By providing access to a broad range of U.S. and Japanese documents, mainly from the spring and summer of 1945, interested readers can see for themselves the crucial source material that scholars have used to shape narrative accounts of the historical developments and to frame their arguments about the questions that have provoked controversy over the years. To help readers who are less familiar with the debates, commentary on some of the documents will point out, although far from comprehensively, some of the ways in which they have been interpreted. With direct access to the documents, readers may develop their own answers to the questions raised above. The documents may even provoke new questions.

Contributors to the historical controversy have deployed the documents selected here to support their arguments about the first use of nuclear weapons and the end of World War II. The editor has closely reviewed the footnotes and endnotes in a variety of articles and books and selected documents cited by participants on the various sides of the controversy. [5] While the editor has a point of view on the issues, to the greatest extent possible he has tried to not let that influence document selection, e.g., by selectively withholding or including documents that may buttress one point of view or the other. The task of compilation involved consultation of primary sources at the National Archives, mainly in Manhattan Project files held in the records of the Army Corps of Engineers, Record Group 77, but also in the archival records of the National Security Agency. Private collections were also important, such as the Henry L. Stimson Papers held at Yale University (although available on microfilm, for example, at the Library of Congress) and the papers of W. Averell Harriman at the Library of Congress. To a great extent the documents selected for this compilation have been declassified for years, even decades; the most recent declassifications were in the 1990s.

The U.S. documents cited here will be familiar to many knowledgeable readers on the Hiroshima-Nagasaki controversy and the history of the Manhattan Project. To provide a fuller picture of the transition from U.S.-Japanese antagonism to reconciliation, the editor has done what could be done within time and resource constraints to present information on the activities and points of view of Japanese policymakers and diplomats. This includes a number of formerly top secret summaries of intercepted Japanese diplomatic communications, which enable interested readers to form their own judgments about the direction of Japanese diplomacy in the weeks before the atomic bombings. Moreover, to shed light on the considerations that induced Japan’s surrender, this briefing book includes new translations of Japanese primary sources on crucial events, including accounts of the conferences on August 9 and 14, where Emperor Hirohito made decisions to accept Allied terms of surrender.

[ Editor’s Note: Originally prepared in July 2005 this posting has been updated, with new documents, changes in organization, and other editorial changes. As noted, some documents relating to the origins of the Manhattan Project have been included in addition to entries from the Robert P. Meiklejohn diaries and translations of a few Soviet documents, among other items. Moreover, recent significant contributions to the scholarly literature have been taken into account.]

I. Background on the U.S. Atomic Project

Documents 1A-C: Report of the Uranium Committee

1A . Arthur H. Compton, National Academy of Sciences Committee on Atomic Fission, to Frank Jewett, President, National Academy of Sciences, 17 May 1941, Secret

1B . Report to the President of the National Academy of Sciences by the Academy Committee on Uranium, 6 November 1941, Secret

1C . Vannevar Bush, Director, Office of Scientific Research and Development, to President Roosevelt, 27 November 1941, Secret

Source: National Archives, Records of the Office of Scientific Research and Development, Record Group 227 (hereinafter RG 227), Bush-Conant papers microfilm collection, Roll 1, Target 2, Folder 1, "S-1 Historical File, Section A (1940-1941)."

This set of documents concerns the work of the Uranium Committee of the National Academy of Sciences, an exploratory project that was the lead-up to the actual production effort undertaken by the Manhattan Project. The initial report, May 1941, showed how leading American scientists grappled with the potential of nuclear energy for military purposes. At the outset, three possibilities were envisioned: radiological warfare, a power source for submarines and ships, and explosives. To produce material for any of those purposes required a capability to separate uranium isotopes in order to produce fissionable U-235. Also necessary for those capabilities was the production of a nuclear chain reaction. At the time of the first report, various methods for producing a chain reaction were envisioned and money was being budgeted to try them out.

Later that year, the Uranium Committee completed its report and OSRD Chairman Vannevar Bush reported the findings to President Roosevelt: As Bush emphasized, the U.S. findings were more conservative than those in the British MAUD report: the bomb would be somewhat “less effective,” would take longer to produce, and at a higher cost. One of the report’s key findings was that a fission bomb of superlatively destructive power will result from bringing quickly together a sufficient mass of element U235.” That was a certainty, “as sure as any untried prediction based upon theory and experiment can be.” The critically important task was to develop ways and means to separate highly enriched uranium from uranium-238. To get production going, Bush wanted to establish a “carefully chosen engineering group to study plans for possible production.” This was the basis of the Top Policy Group, or the S-1 Committee, which Bush and James B. Conant quickly established. [6]

In its discussion of the effects of an atomic weapon, the committee considered both blast and radiological damage. With respect to the latter, “It is possible that the destructive effects on life caused by the intense radioactivity of the products of the explosion may be as important as those of the explosion itself.” This insight was overlooked when top officials of the Manhattan Project considered the targeting of Japan during 1945. [7]

Documents 2A-B: Going Ahead with the Bomb

2A : Vannevar Bush to President Roosevelt, 9 March 1942, with memo from Roosevelt attached, 11 March 1942, Secret

2B : Vannevar Bush to President Roosevelt, 16 December 1942, Secret (report not attached)

Sources: 2A: RG 227, Bush-Conant papers microfilm collection, Roll 1, Target 2, Folder 1, "S-1 Historical File, Section II (1941-1942): 2B: Bush-Conant papers, S-1 Historical File, Reports to and Conferences with the President (1942-1944)

The Manhattan Project never had an official charter establishing it and defining its mission, but these two documents are the functional equivalent of a charter, in terms of presidential approvals for the mission, not to mention for a huge budget. In a progress report, Bush told President Roosevelt that the bomb project was on a pilot plant basis, but not yet at the production stage. By the summer, once “production plants” would be at work, he proposed that the War Department take over the project. In reply, Roosevelt wrote a short memo endorsing Bush’s ideas as long as absolute secrecy could be maintained. According to Robert S. Norris, this was “the fateful decision” to turn over the atomic project to military control. [8]

Some months later, with the Manhattan Project already underway and under the direction of General Leslie Grove, Bush outlined to Roosevelt the effort necessary to produce six fission bombs. With the goal of having enough fissile material by the first half of 1945 to produce the bombs, Bush was worried that the Germans might get there first. Thus, he wanted Roosevelt’s instructions as to whether the project should be “vigorously pushed throughout.” Unlike the pilot plant proposal described above, Bush described a real production order for the bomb, at an estimated cost of a “serious figure”: $400 million, which was an optimistic projection given the eventual cost of $1.9 billion. To keep the secret, Bush wanted to avoid a “ruinous” appropriations request to Congress and asked Roosevelt to ask Congress for the necessary discretionary funds. Initialed by President Roosevelt (“VB OK FDR”), this may have been the closest that he came to a formal approval of the Manhattan Project.

Document 3 : Memorandum by Leslie R. Grove, “Policy Meeting, 5/5/43,” Top Secret

Source:  National Archives, Record Group 77, Records of the Army Corps of Engineers (hereinafter RG 77), Manhattan Engineering District (MED), Minutes of the Military Policy Meeting (5 May 1943), Correspondence (“Top Secret”) of the Manhattan Engineer District, 1942-1946, microfilm publication M1109 (Washington, D.C.: National Archives and Records Administration, 1980), Roll 3, Target 6, Folder 23, “Military Policy Committee, Minutes of Meetings”

Before the Manhattan Project had produced any weapons, senior U.S. government officials had Japanese targets in mind. Besides discussing programmatic matters (e.g., status of gaseous diffusion plants, heavy water production for reactors, and staffing at Las Alamos), the participants agreed that the first use could be Japanese naval forces concentrated at Truk Harbor, an atoll in the Caroline Islands. If there was a misfire the weapon would be difficult for the Japanese to recover, which would not be the case if Tokyo was targeted. Targeting Germany was rejected because the Germans were considered more likely to “secure knowledge” from a defective weapon than the Japanese. That is, the United States could possibly be in danger if the Nazis acquired more knowledge about how to build a bomb. [9]

Document 4 :   Memo from General Groves to the Chief of Staff [Marshall], “Atomic Fission Bombs – Present Status and Expected Progress,” 7 August 1944, Top Secret, excised copy

Source: RG 77, Correspondence ("Top Secret") of the Manhattan Engineer District, 1942-1946, file 25M

This memorandum from General Groves to General Marshall captured how far the Manhattan Project had come in less than two years since Bush’s December 1942 report to President Roosevelt .  Groves did not mention this but around the time he wrote this the Manhattan Project had working at its far-flung installations over  125,000 people  ; taking into account high labor turnover some 485,000 people worked on the project (1 out of every 250 people in the country at that time). What these people were laboring to construct, directly or indirectly, were two types of weapons—a gun-type weapon using U-235 and an implosion weapon using plutonium (although the possibility of U-235 was also under consideration). As the scientists had learned, a gun-type weapon based on plutonium was “impossible” because that element had an “unexpected property”: spontaneous neutron emissions would cause the weapon to “fizzle.” [10]  For both the gun-type and the implosion weapons, a production schedule had been established and both would be available during 1945. The discussion of weapons effects centered on blast damage models; radiation and other effects were overlooked.

Document 5 : Memorandum from Vannevar Bush and James B. Conant, Office of Scientific Research and Development, to Secretary of War, September 30, 1944, Top Secret

Source: RG 77, Harrison-Bundy Files (H-B Files), folder 69 (copy from microfilm)

While Groves worried about the engineering and production problems, key War Department advisers were becoming troubled over the diplomatic and political implications of these enormously powerful weapons and the dangers of a global nuclear arms race. Concerned that President Roosevelt had an overly “cavalier” belief about the possibility of maintaining a post-war Anglo-American atomic monopoly, Bush and Conant recognized the limits of secrecy and wanted to disabuse senior officials of the notion that an atomic monopoly was possible. To suggest alternatives, they drafted this memorandum about the importance of the international exchange of information and international inspection to stem dangerous nuclear competition. [11]

Documents 6A-D: President Truman Learns the Secret:

6A : Memorandum for the Secretary of War from General L. R. Groves, “Atomic Fission Bombs,” April 23, 1945

6B : Memorandum discussed with the President, April 25, 1945

6C : [Untitled memorandum by General L.R. Groves, April 25, 1945

6D : Diary Entry, April 25, 1945

Sources: A: RG 77, Commanding General’s file no. 24, tab D; B: Henry Stimson Diary, Sterling Library, Yale University (microfilm at Library of Congress); C: Source: Record Group 200, Papers of General Leslie R. Groves, Correspondence 1941-1970, box 3, “F”; D: Henry Stimson Diary, Sterling Library, Yale University (microfilm at Library of Congress)

Soon after he was sworn in as president following President Roosevelt’s death, Harry Truman learned about the top secret Manhattan Project from a briefing from Secretary of War Stimson and Manhattan Project chief General Groves, who went through the “back door” to escape the watchful press. Stimson, who later wrote up the meeting in his diary, also prepared a discussion paper, which raised broader policy issues associated with the imminent possession of “the most terrible weapon ever known in human history.” In a background report prepared for the meeting, Groves provided a detailed overview of the bomb project from the raw materials to processing nuclear fuel to assembling the weapons to plans for using them, which were starting to crystallize.

With respect to the point about assembling the weapons, the first gun-type weapon “should be ready about 1 August 1945” while an implosion weapon would also be available that month. “The target is and was always expected to be Japan.” The question whether Truman “inherited assumptions” from the Roosevelt administration that that the bomb would be used has been a controversial one. Alperovitz and Sherwin have argued that Truman made “a real decision” to use the bomb on Japan by choosing “between various forms of diplomacy and warfare.” In contrast, Bernstein found that Truman “never questioned [the] assumption” that the bomb would and should be used. Norris also noted that “Truman’s `decision’ was a decision not to override previous plans to use the bomb.” [12]

II. Targeting Japan

Document 7 : Commander F. L. Ashworth to Major General L.R. Groves, “The Base of Operations of the 509 th  Composite Group,” February 24, 1945, Top Secret

Source: RG 77, MED Records, Top Secret Documents, File no. 5g

The force of B-29 nuclear delivery vehicles that was being readied for first nuclear use—the Army Air Force’s 509 th  Composite Group—required an operational base in the Western Pacific. In late February 1945, months before atomic bombs were ready for use, the high command selected Tinian, an island in the Northern Marianas Islands, for that base.

Document 8 : Headquarters XXI Bomber Command, “Tactical Mission Report, Mission No. 40 Flown 10 March 1945,”n.d., Secret

Source: Library of Congress, Curtis LeMay Papers, Box B-36

As part of the war with Japan, the Army Air Force waged a campaign to destroy major industrial centers with incendiary bombs. This document is General Curtis LeMay’s report on the firebombing of Tokyo--“the most destructive air raid in history”--which burned down over 16 square miles of the city, killed up to 100,000 civilians (the official figure was 83,793), injured more than 40,000, and made over 1 million homeless.  [13]  According to the “Foreword,” the purpose of the raid, which dropped 1,665 tons of incendiary bombs, was to destroy industrial and strategic targets “ not  to bomb indiscriminately civilian populations.” Air Force planners, however, did not distinguish civilian workers from the industrial and strategic structures that they were trying to destroy.

The killing of workers in the urban-industrial sector was one of the explicit goals of the air campaign against Japanese cities. According to a Joint Chiefs of Staff report on Japanese target systems, expected results from the bombing campaign included: “The absorption of man-hours in repair and relief; the dislocation of labor by casualty; the interruption of public services necessary to production, and above all the destruction of factories engaged in war industry.” While Stimson would later raise questions about the bombing of Japanese cities, he was largely disengaged from the details (as he was with atomic targeting). [14]

Firebombing raids on other cities followed Tokyo, including Osaka, Kobe, Yokahama, and Nagoya, but with fewer casualties (many civilians had fled the cities). For some historians, the urban fire-bombing strategy facilitated atomic targeting by creating a “new moral context,” in which earlier proscriptions against intentional targeting of civilians had eroded. [15]

Document 9 : Notes on Initial Meeting of Target Committee, May 2, 1945, Top Secret

Source: RG 77, MED Records, Top Secret Documents, File no. 5d (copy from microfilm)

On 27 April, military officers and nuclear scientists met to discuss bombing techniques, criteria for target selection, and overall mission requirements. The discussion of “available targets” included Hiroshima, the “largest untouched target not on the 21 st  Bomber Command priority list.” But other targets were under consideration, including Yawata (northern Kyushu), Yokohama, and Tokyo (even though it was practically “rubble.”) The problem was that the Air Force had a policy of “laying waste” to Japan’s cities which created tension with the objective of reserving some urban targets for nuclear destruction.  [16]

Document 10 : Memorandum from J. R. Oppenheimer to Brigadier General Farrell, May 11, 1945

Source: RG 77, MED Records, Top Secret Documents, File no. 5g (copy from microfilm)

As director of Los Alamos Laboratory, Oppenheimer’s priority was producing a deliverable bomb, but not so much the effects of the weapon on the people at the target. In keeping with General Groves’ emphasis on compartmentalization, the Manhattan Project experts on the effects of radiation on human biology were at the MetLab and other offices and had no interaction with the production and targeting units. In this short memorandum to Groves’ deputy, General Farrell, Oppenheimer explained the need for precautions because of the radiological dangers of a nuclear detonation. The initial radiation from the detonation would be fatal within a radius of about 6/10ths of a mile and “injurious” within a radius of a mile. The point was to keep the bombing mission crew safe; concern about radiation effects had no impact on targeting decisions.  [17]

Document 11 : Memorandum from Major J. A. Derry and Dr. N.F. Ramsey to General L.R. Groves, “Summary of Target Committee Meetings on 10 and 11 May 1945,” May 12, 1945, Top Secret

Scientists and officers held further discussion of bombing mission requirements, including height of detonation, weather, radiation effects (Oppenheimer’s memo), plans for possible mission abort, and the various aspects of target selection, including priority cities (“a large urban area of more than three miles diameter”) and psychological dimension. As for target cities, the committee agreed that the following should be exempt from Army Air Force bombing so they would be available for nuclear targeting: Kyoto, Hiroshima, Yokohama, and Kokura Arsenal. Japan’s cultural capital, Kyoto, would not stay on the list. Pressure from Secretary of War Stimson had already taken Kyoto off the list of targets for incendiary bombings and he would successfully object to the atomic bombing of that city.  [18]

Document 12 : Stimson Diary Entries, May 14 and 15, 1945

Source: Henry Stimson Diary, Sterling Library, Yale University (microfilm at Library of Congress)

On May 14 and 15, Stimson had several conversations involving S-1 (the atomic bomb); during a talk with Assistant Secretary of War John J. McCloy, he estimated that possession of the bomb gave Washington a tremendous advantage—“held all the cards,” a “royal straight flush”-- in dealing with Moscow on post-war problems: “They can’t get along without our help and industries and we have coming into action a weapon which will be unique.” The next day a discussion of divergences with Moscow over the Far East made Stimson wonder whether the atomic bomb would be ready when Truman met with Stalin in July. If it was, he believed that the bomb would be the “master card” in U.S. diplomacy. This and other entries from the Stimson diary (as well as the entry from the Davies diary that follows) are important to arguments developed by Gar Alperovitz and Barton J. Bernstein, among others, although with significantly different emphases, that in light of controversies with the Soviet Union over Eastern Europe and other areas, top officials in the Truman administration believed that possessing the atomic bomb would provide them with significant leverage for inducing Moscow’s acquiescence in U.S. objectives. [19]

Document 13 : Davies Diary entry for May 21, 1945

Source: Joseph E. Davies Papers, Library of Congress, box 17, 21 May 1945

While officials at the Pentagon continued to look closely at the problem of atomic targets, President Truman, like Stimson, was thinking about the diplomatic implications of the bomb. During a conversation with Joseph E. Davies, a prominent Washington lawyer and former ambassador to the Soviet Union, Truman said that he wanted to delay talks with Stalin and Churchill until July when the first atomic device had been tested. Alperovitz treated this entry as evidence in support of the atomic diplomacy argument, but other historians, ranging from Robert Maddox to Gabriel Kolko, have denied that the timing of the Potsdam conference had anything to do with the goal of using the bomb to intimidate the Soviets. [20]

Document 14 : Letter, O. C. Brewster to President Truman, 24 May 1945, with note from Stimson to Marshall, 30 May 1945, attached, secret

Source: Harrison-Bundy Files relating to the Development of the Atomic Bomb, 1942-1946, microfilm publication M1108 (Washington, D.C.: National Archives and Records Administration, 1980), File 77: "Interim Committee - International Control."

In what Stimson called the “letter of an honest man,” Oswald C. Brewster sent President Truman a profound analysis of the danger and unfeasibility of a U.S. atomic monopoly.  [21]  An engineer for the Kellex Corporation, which was involved in the gas diffusion project to enrich uranium, Brewster recognized that the objective was fissile material for a weapon. That goal, he feared, raised terrifying prospects with implications for the “inevitable destruction of our present day civilization.” Once the U.S. had used the bomb in combat other great powers would not tolerate a monopoly by any nation and the sole possessor would be “be the most hated and feared nation on earth.” Even the U.S.’s closest allies would want the bomb because “how could they know where our friendship might be five, ten, or twenty years hence.” Nuclear proliferation and arms races would be certain unless the U.S. worked toward international supervision and inspection of nuclear plants.

Brewster suggested that Japan could be used as a “target” for a “demonstration” of the bomb, which he did not further define. His implicit preference, however, was for non-use; he wrote that it would be better to take U.S. casualties in “conquering Japan” than “to bring upon the world the tragedy of unrestrained competitive production of this material.”

Document 15 : Minutes of Third Target Committee Meeting – Washington, May 28, 1945, Top Secret

More updates on training missions, target selection, and conditions required for successful detonation over the target. The target would be a city--either Hiroshima, Kyoto (still on the list), or Niigata--but specific “aiming points” would not be specified at that time nor would industrial “pin point” targets because they were likely to be on the “fringes” a city. The bomb would be dropped in the city’s center. “Pumpkins” referred to bright orange, pumpkin-shaped high explosive bombs—shaped like the “Fat Man” implosion weapon--used for bombing run test missions.

Document 16 : General Lauris Norstad to Commanding General, XXI Bomber Command, “509 th  Composite Group; Special Functions,” May 29, 1945, Top Secret

The 509 th  Composite Group’s cover story for its secret mission was the preparation of “Pumpkins” for use in battle. In this memorandum, Norstad reviewed the complex requirements for preparing B-29s and their crew for successful nuclear strikes.

Document 17 : Assistant Secretary of War John J. McCloy, “Memorandum of Conversation with General Marshal May 29, 1945 – 11:45 p.m.,” Top Secret

Source: Record Group 107, Office of the Secretary of War, Formerly Top Secret Correspondence of Secretary of War Stimson (“Safe File”), July 1940-September 1945, box 12, S-1

Tacitly dissenting from the Targeting Committee’s recommendations, Army Chief of Staff George Marshall argued for initial nuclear use against a clear-cut military target such as a “large naval installation.” If that did not work, manufacturing areas could be targeted, but only after warning their inhabitants. Marshall noted the “opprobrium which might follow from an ill considered employment of such force.” This document has played a role in arguments developed by Barton J. Bernstein that figures such as Marshall and Stimson were “caught between an older morality that opposed the intentional killing of non-combatants and a newer one that stressed virtually total war.” [22]  

Document 18 : “Notes of the Interim Committee Meeting Thursday, 31 May 1945, 10:00 A.M. to 1:15 P.M. – 2:15 P.M. to 4:15 P.M., ” n.d., Top Secret

Source: RG 77, MED Records, H-B files, folder no. 100 (copy from microfilm)

With Secretary of War Stimson presiding, members of the committee heard reports on a variety of Manhattan Project issues, including the stages of development of the atomic project, problems of secrecy, the possibility of informing the Soviet Union, cooperation with “like-minded” powers, the military impact of the bomb on Japan, and the problem of “undesirable scientists.” Interested in producing the “greatest psychological effect,” the Committee members agreed that the “most desirable target would be a vital war plant employing a large number of workers and closely surrounded by workers’ houses.” Exactly how the mass deaths of civilians would persuade Japanese rulers to surrender was not discussed. Bernstein has argued that this target choice represented an uneasy endorsement of “terror bombing”--the target was not exclusively military or civilian; nevertheless, worker’s housing would include non-combatant men, women, and children. [23]  It is possible that Truman was informed of such discussions and their conclusions, although he clung to a belief that the prospective targets were strictly military.

Document 19 : General George A. Lincoln to General Hull, June 4, 1945, enclosing draft, Top Secret

Source: Record Group 165, Records of the War Department General and Special Staffs, American-British-Canadian Top Secret Correspondence, Box 504, “ABC 387 Japan (15 Feb. 45)

George A. Lincoln, chief of the Strategy and Policy Group at U.S. Army’s Operations Department, commented on a memorandum by former President Herbert Hoover that Stimson had passed on for analysis. Hoover proposed a compromise solution with Japan that would allow Tokyo to retain part of its empire in East Asia (including Korea and Japan) as a way to head off Soviet influence in the region. While Lincoln believed that the proposed peace teams were militarily acceptable he doubted that they were workable or that they could check Soviet “expansion” which he saw as an inescapable result of World War II. As to how the war with Japan would end, he saw it as “unpredictable,” but speculated that “it will take Russian entry into the war, combined with a landing, or imminent threat of a landing, on Japan proper by us, to convince them of the hopelessness of their situation.” Lincoln derided Hoover’s casualty estimate of 500,000. J. Samuel Walker has cited this document to make the point that “contrary to revisionist assertions, American policymakers in the summer of 1945 were far from certain that the Soviet invasion of Manchuria would be enough in itself to force a Japanese surrender.”  [24]

Document 20 : Memorandum from R. Gordon Arneson, Interim Committee Secretary, to Mr. Harrison, June 6, 1945, Top Secret

In a memorandum to George Harrison, Stimson’s special assistant on Manhattan Project matters, Arneson noted actions taken at the recent Interim Committee meetings, including target criterion and an attack “without prior warning.”

Document 21 : Memorandum of Conference with the President, June 6, 1945, Top Secret

Source: Henry Stimson Papers, Sterling Library, Yale University (microfilm at Library of Congress)

Stimson and Truman began this meeting by discussing how they should handle a conflict with French President DeGaulle over the movement by French forces into Italian territory. (Truman finally cut off military aid to France to compel the French to pull back).  [25]  As evident from the discussion, Stimson strongly disliked de Gaulle whom he regarded as “psychopathic.” The conversation soon turned to the atomic bomb, with some discussion about plans to inform the Soviets but only after a successful test. Both agreed that the possibility of a nuclear “partnership” with Moscow would depend on “quid pro quos”: “the settlement of the Polish, Rumanian, Yugoslavian, and Manchurian problems.”

At the end, Stimson shared his doubts about targeting cities and killing civilians through area bombing because of its impact on the U.S.’s reputation as well as on the problem of finding targets for the atomic bomb. Barton Bernstein has also pointed to this as additional evidence of the influence on Stimson of an “an older morality.” While concerned about the U.S.’s reputation, Stimson did not want the Air Force to bomb Japanese cities so thoroughly that the “new weapon would not have a fair background to show its strength,” a comment that made Truman laugh.  The discussion of “area bombing” may have reminded him that Japanese civilians remained at risk from U.S. bombing operations.

III. Debates on Alternatives to First Use and Unconditional Surrender

Document 22 : Memorandum from Arthur B. Compton to the Secretary of War, enclosing “Memorandum on `Political and Social Problems,’ from Members of the `Metallurgical Laboratory’ of the University of Chicago,” June 12, 1945, Secret

Source: RG 77, MED Records, H-B files, folder no. 76 (copy from microfilm)

Physicists Leo Szilard and James Franck, a Nobel Prize winner, were on the staff of the “Metallurgical Laboratory” at the University of Chicago, a cover for the Manhattan Project program to produce fuel for the bomb. The outspoken Szilard was not involved in operational work on the bomb and General Groves kept him under surveillance but Met Lab director Arthur Compton found Szilard useful to have around. Concerned with the long-run implications of the bomb, Franck chaired a committee, in which Szilard and Eugene Rabinowitch were major contributors, that produced a report rejecting a surprise attack on Japan and recommended instead a demonstration of the bomb on the “desert or a barren island.” Arguing that a nuclear arms race “will be on in earnest not later than the morning after our first demonstration of the existence of nuclear weapons,” the committee saw international control as the alternative. That possibility would be difficult if the United States made first military use of the weapon. Compton raised doubts about the recommendations but urged Stimson to study the report. Martin Sherwin has argued that the Franck committee shared an important assumption with Truman et al.--that an “atomic attack against Japan would `shock’ the Russians”--but drew entirely different conclusions about the import of such a shock.  [26]

Document 23 : Memorandum from Acting Secretary of State Joseph Grew to the President, “Analysis of Memorandum Presented by Mr. Hoover,” June 13, 1945

Source: Record Group 107, Office of the Secretary of War, Formerly Top Secret Correspondence of Secretary of War Stimson (“Safe File”), July 1940-September 1945, box 8, Japan (After December 7/41)

A former ambassador to Japan, Joseph Grew’s extensive knowledge of Japanese politics and culture informed his stance toward the concept of unconditional surrender. He believed it essential that the United States declare its intention to preserve the institution of the emperor. As he argued in this memorandum to President Truman, “failure on our part to clarify our intentions” on the status of the emperor “will insure prolongation of the war and cost a large number of human lives.” Documents like this have played a role in arguments developed by Alperovitz that Truman and his advisers had alternatives to using the bomb such as modifying unconditional surrender and that anti-Soviet considerations weighed most heavily in their thinking. By contrast, Herbert P. Bix has suggested that the Japanese leadership would “probably not” have surrendered if the Truman administration had spelled out the status of the emperor. [27]

Document 24 : Memorandum from Chief of Staff Marshall to the Secretary of War, 15 June 1945, enclosing “Memorandum of Comments on `Ending the Japanese War,’” prepared by George A. Lincoln, June 14, 1945, Top Secret

Commenting on another memorandum by Herbert Hoover, George A. Lincoln discussed war aims, face-saving proposals for Japan, and the nature of the proposed declaration to the Japanese government, including the problem of defining “unconditional surrender.” Lincoln argued against modifying the concept of unconditional surrender: if it is “phrased so as to invite negotiation” he saw risks of prolonging the war or a “compromise peace.” J. Samuel Walker has observed that those risks help explain why senior officials were unwilling to modify the demand for unconditional surrender. [28]

Document 25 : Memorandum by J. R. Oppenheimer, “Recommendations on the Immediate Use of Nuclear Weapons,” June 16, 1945, Top Secret

In a report to Stimson, Oppenheimer and colleagues on the scientific advisory panel--Arthur Compton, Ernest O. Lawrence, and Enrico Fermi—tacitly disagreed with the report of the “Met Lab” scientists. The panel argued for early military use but not before informing key allies about the atomic project to open a dialogue on “how we can cooperate in making this development contribute to improved international relations.”

Document 26 : “Minutes of Meeting Held at the White House on Monday, 18 June 1945 at 1530,” Top Secret

Source: Record Group 218, Records of the Joint Chiefs of Staff, Central Decimal Files, 1942-1945, box 198 334 JCS (2-2-45) Mtg 186 th -194 th

With the devastating battle for Okinawa winding up, Truman and the Joint Chiefs stepped back and considered what it would take to secure Japan’s surrender. The discussion depicted a Japan that, by 1 November, would be close to defeat, with great destruction and economic losses produced by aerial bombing and naval blockade, but not ready to capitulate. Marshall believed that the latter required Soviet entry and an invasion of Kyushu, even suggesting that Soviet entry might be the “decisive action levering them into capitulation.” Truman and the Chiefs reviewed plans to land troops on Kyushu on 1 November, which Marshall believed was essential because air power was not decisive. He believed that casualties would not be more than those produced by the battle for Luzon, some 31,000. This account hints at discussion of the atomic bomb (“certain other matters”), but no documents disclose that part of the meeting.

The record of this meeting has figured in the complex debate over the estimates of casualties stemming from a possible invasion of Japan. While post-war justifications for the bomb suggested that an invasion of Japan could have produced very high levels of casualties (dead, wounded, or missing), from hundreds of thousands to a million, historians have vigorously debated the extent to which the estimates were inflated.  [29]

According to accounts based on post-war recollections and interviews, during the meeting McCloy raised the possibility of winding up the war by guaranteeing the preservation of the emperor albeit as a constitutional monarch. If that failed to persuade Tokyo, he proposed that the United States disclose the secret of the atomic bomb to secure Japan’s unconditional surrender. While McCloy later recalled that Truman expressed interest, he said that Secretary of State Byrnes squashed the proposal because of his opposition to any “deals” with Japan. Yet, according to Forrest Pogue’s account, when Truman asked McCloy if he had any comments, the latter opened up a discussion of nuclear weapons use by asking “Why not use the bomb?” [30]

Document 27 : Memorandum from R. Gordon Arneson, Interim Committee Secretary, to Mr. Harrison, June 25, 1945, Top Secret

For Harrison’s convenience, Arneson summarized key decisions made at the 21 June meeting of the Interim Committee, including a recommendation that President Truman use the forthcoming conference of allied leaders to inform Stalin about the atomic project. The Committee also reaffirmed earlier recommendations about the use of the bomb at the “earliest opportunity” against “dual targets.” In addition, Arneson included the Committee’s recommendation for revoking part two of the 1944 Quebec agreement which stipulated that the neither the United States nor Great Britain would use the bomb “against third parties without each other’s consent.” Thus, an impulse for unilateral control of nuclear use decisions predated the first use of the bomb.

Document 28 : Memorandum from George L. Harrison to Secretary of War, June 26, 1945, Top Secret

Source: RG 77, MED, H-B files, folder no. 77 (copy from microfilm)

Reminding Stimson about the objections of some Manhattan project scientists to military use of the bomb, Harrison summarized the basic arguments of the Franck report. One recommendation shared by many of the scientists, whether they supported the report or not, was that the United States inform Stalin of the bomb before it was used. This proposal had been the subject of positive discussion by the Interim Committee on the grounds that Soviet confidence was necessary to make possible post-war cooperation on atomic energy.

Document 29 : Memorandum from George L. Harrison to Secretary of War, June 28, 1945, Top Secret, enclosing Ralph Bard’s “Memorandum on the Use of S-1 Bomb,” June 27, 1945

Under Secretary of the Navy Ralph Bard joined those scientists who sought to avoid military use of the bomb; he proposed a “preliminary warning” so that the United States would retain its position as a “great humanitarian nation.” Alperovitz cites evidence that Bard discussed his proposal with Truman who told him that he had already thoroughly examined the problem of advanced warning. This document has also figured in the argument framed by Barton Bernstein that Truman and his advisers took it for granted that the bomb was a legitimate weapon and that there was no reason to explore alternatives to military use. Bernstein, however, notes that Bard later denied that he had a meeting with Truman and that White House appointment logs support that claim. [31]

Document 30 : Memorandum for Mr. McCloy, “Comments re: Proposed Program for Japan,” June 28, 1945, Draft, Top Secret

Source: RG 107, Office of Assistant Secretary of War Formerly Classified Correspondence of John J. McCloy, 1941-1945, box 38, ASW 387 Japan

Despite the interest of some senior officials such as Joseph Grew, Henry Stimson, and John J. McCloy in modifying the concept of unconditional surrender so that the Japanese could be sure that the emperor would be preserved, it remained a highly contentious subject. For example, one of McCloy’s aides, Colonel Fahey, argued against modification of unconditional surrender (see “Appendix ‘C`”).

Document 31 : Assistant Secretary of War John J. McCloy to Colonel Stimson, June 29, 1945, Top Secret

McCloy was part of a drafting committee at work on the text of a proclamation to Japan to be signed by heads of state at the forthcoming Potsdam conference. As McCloy observed the most contentious issue was whether the proclamation should include language about the preservation of the emperor: “This may cause repercussions at home but without it those who seem to know the most about Japan feel there would be very little likelihood of acceptance.”

Document 32 : Memorandum, “Timing of Proposed Demand for Japanese Surrender,” June 29, 1945, Top Secret

Probably the work of General George A. Lincoln at Army Operations, this document was prepared a few weeks before the Potsdam conference when senior officials were starting to finalize the text of the declaration that Truman, Churchill, and Chiang would issue there. The author recommended issuing the declaration “just before the bombardment program [against Japan] reaches its peak.” Next to that suggestion, Stimson or someone in his immediate office, wrote “S1”, implying that the atomic bombing of Japanese cities was highly relevant to the timing issue. Also relevant to Japanese thinking about surrender, the author speculated, was the Soviet attack on their forces after a declaration of war.

Document 33 : Stimson memorandum to The President, “Proposed Program for Japan,” 2 July 1945, Top Secret

Source: Naval Aide to the President Files, box 4, Berlin Conference File, Volume XI - Miscellaneous papers: Japan, Harry S. Truman Presidential Library

On 2 July Stimson presented to President Truman a proposal that he had worked up with colleagues in the War Department, including McCloy, Marshall, and Grew. The proposal has been characterized as “the most comprehensive attempt by any American policymaker to leverage diplomacy” in order to shorten the Pacific War. Stimson had in mind a “carefully timed warning” delivered before the invasion of Japan. Some of the key elements of Stimson’s argument were his assumption that “Japan is susceptible to reason” and that Japanese might be even more inclined to surrender if “we do not exclude a constitutional monarchy under her present dynasty.” The possibility of a Soviet attack would be part of the “threat.” As part of the threat message, Stimson alluded to the “inevitability and completeness of the destruction” which Japan could suffer, but he did not make it clear whether unconditional surrender terms should be clarified before using the atomic bomb. Truman read Stimson’s proposal, which he said was “powerful,” but made no commitments to the details, e.g., the position of the emperor.  [32]

Document 34 : Minutes, Secretary’s Staff Committee, Saturday Morning, July 7, 1945, 133d Meeting, Top Secret

Source: Record Group 353, Records of Interdepartmental and Intradepartmental Committees, Secretary’s Staff Meetings Minutes, 1944-1947 (copy from microfilm)

The possibility of modifying the concept of unconditional surrender so that it guaranteed the continuation of the emperor remained hotly contested within the U.S. government. Here senior State Department officials, Under Secretary Joseph Grew on one side, and Assistant Secretary Dean Acheson and Archibald MacLeish on the other, engaged in hot debate.

Document 35 : Combined Chiefs of Staff, “Estimate of the Enemy Situation (as of 6 July 1945, C.C.S 643/3, July 8, 1945, Secret (Appendices Not Included)

Source: RG 218, Central Decimal Files, 1943-1945, CCS 381 (6-4-45), Sec. 2 Pt. 5

This review of Japanese capabilities and intentions portrays an economy and society under “tremendous strain”; nevertheless, “the ground component of the Japanese armed forces remains Japan’s greatest military asset.” Alperovitz sees statements in this estimate about the impact of Soviet entry into the war and the possibility of a conditional surrender involving survival of the emperor as an institution as more evidence that the policymakers saw alternatives to nuclear weapons use. By contrast, Richard Frank takes note of the estimate’s depiction of the Japanese army’s terms for peace: “for surrender to be acceptable to the Japanese army it would be necessary for the military leaders to believe that it would not entail discrediting the warrior tradition and that it would permit the ultimate resurgence of a military in Japan.” That, Frank argues, would have been “unacceptable to any Allied policy maker.” [33]

Document 36 : Cable to Secretary of State from Acting Secretary Joseph Grew, July 16, 1945, Top Secret

Source: Record Group 59, Decimal Files 1945-1949, 740.0011 PW (PE)/7-1645

On the eve of the Potsdam Conference, a State Department draft of the proclamation to Japan contained language which modified unconditional surrender by promising to retain the emperor. When former Secretary of State Cordell Hull learned about it he outlined his objections to Byrnes, arguing that it might be better to wait “the climax of allied bombing and Russia’s entry into the war.” Byrnes was already inclined to reject that part of the draft, but Hull’s argument may have reinforced his decision.

Document 37 : Letter from Stimson to Byrnes, enclosing memorandum to the President, “The Conduct of the War with Japan,” 16 July 1945, Top Secret

Source: Henry L. Stimson Papers (MS 465), Sterling Library, Yale University (reel 113) (microfilm at Library of Congress)

Still interested in trying to find ways to “warn Japan into surrender,” this represents an attempt by Stimson before the Potsdam conference, to persuade Truman and Byrnes to agree to issue warnings to Japan prior to the use of the bomb. The warning would draw on the draft State-War proclamation to Japan; presumably, the one criticized by Hull (above) which included language about the emperor .  Presumably the clarified warning would be issued prior to the use of the bomb; if the Japanese persisted in fighting then “the full force of our new weapons should be brought to bear” and a “heavier” warning would be issued backed by the “actual entrance of the Russians in the war.” Possibly, as Malloy has argued, Stimson was motivated by concerns about using the bomb against civilians and cities, but his latest proposal would meet resistance at Potsdam from Byrnes and other. [34]

Document 38 : R. E. Lapp, Leo Szilard et al., “A Petition to the President of the United States,” July 17, 1945

On the eve of the Potsdam conference, Leo Szilard circulated a petition as part of a final effort to discourage military use of the bomb. Signed by about 68 Manhattan Project scientists, mainly physicists and biologists (copies with the remaining signatures are in the archival file), the petition did not explicitly reject military use, but raised questions about an arms race that military use could instigate and requested Truman to publicize detailed terms for Japanese surrender. Truman, already on his way to Europe, never saw the petition. [35]

IV. The Japanese Search for Soviet Mediation

Documents 39A-B: Magic

39A : William F. Friedman, Consultant (Armed Forces Security Agency), “A Short History of U.S. COMINT Activities,” 19 February 1952, Top Secret

39B :“Magic” – Diplomatic Summary, War Department, Office of Assistant Chief of Staff, G-2, No. 1204 – July 12, 1945, Top Secret Ultra

Sources: A: National Security Agency Mandatory declassification review release; B: Record Group 457, Records of the National Security Agency/Central Security Service, “Magic” Diplomatic Summaries 1942-1945, box 18

Beginning in September 1940, U.S. military intelligence began to decrypt routinely, under the “Purple” code-name, the intercepted cable traffic of the Japanese Foreign Ministry. Collectively the decoded messages were known as “Magic.” How this came about is explained in an internal history of pre-war and World War II Army and Navy code-breaking activities prepared by  William F. Friedman , a central figure in the development of U.S. government cryptology during the 20 th  century. The National Security Agency kept the ‘Magic” diplomatic and military summaries classified for many years and did not release the entire series for 1942 through August 1945 until the early 1990s. [36]

The 12 July 1945 “Magic” summary includes a report on a cable from Japanese Foreign Minister Shigenori Togo to Ambassador Naotake Sato in Moscow concerning the Emperor’s decision to seek Soviet help in ending the war. Not knowing that the Soviets had already made a commitment to their Allies to declare war on Japan, Tokyo fruitlessly pursued this option for several weeks. The “Magic” intercepts from mid-July have figured in Gar Alperovitz’s argument that Truman and his advisers recognized that the Emperor was ready to capitulate if the Allies showed more flexibility on the demand for unconditional surrender. This point is central to Alperovitz’s thesis that top U.S. officials recognized a “two-step logic”: relaxing unconditional surrender and a Soviet declaration of war would have been enough to induce Japan’s surrender without the use of the bomb. [37]

Document 40 : John Weckerling, Deputy Assistant Chief of Staff, G-2, July 12, 1945, to Deputy Chief of Staff, “Japanese Peace Offer,” 13 July 1945, Top Secret Ultra

Source: RG 165, Army Operations OPD Executive File #17, Item 13 (copy courtesy of J. Samuel Walker)

The day after the Togo message was reported, Army intelligence chief Weckerling proposed several possible explanations of the Japanese diplomatic initiative. Robert J. Maddox has cited this document to support his argument that top U.S. officials recognized that Japan was not close to surrender because Japan was trying to “stave off defeat.” In a close analysis of this document, Tsuyoshi Hasegawa, who is also skeptical of claims that the Japanese had decided to surrender, argues that each of the three possibilities proposed by Weckerling “contained an element of truth, but none was entirely correct”. For example, the “governing clique” that supported the peace moves was not trying to “stave off defeat” but was seeking Soviet help to end the war. [38]

Document 41 : “Magic” – Diplomatic Summary, War Department, Office of Assistant Chief of Staff, G-2, No. 1205 – July 13, 1945, Top Secret Ultra

Source: Record Group 457, Records of the National Security Agency/Central Security Service, “Magic” Diplomatic Summaries 1942-1945, box 18

The day after he told Sato about the current thinking on Soviet mediation, Togo requested the Ambassador to see Soviet Foreign Minister Vyacheslav Molotov and tell him of the Emperor’s “private intention to send Prince Konoye as a Special Envoy” to Moscow. Before he received Togo’s message, Sato had already met with Molotov on another matter.

Document 42 : “Magic” – Diplomatic Summary, War Department, Office of Assistant Chief of Staff, G-2, No. 1210 – July 17, 1945, Top Secret Ultra

Source: Record Group 457, Records of the National Security Agency/Central Security Service, “Magic” Diplomatic Summaries 1942-1945, box 18.

Another intercept of a cable from Togo to Sato shows that the Foreign Minister rejected unconditional surrender and that the Emperor was not “asking the Russian’s mediation in anything like unconditional surrender.” Incidentally, this “`Magic’ Diplomatic Summary” indicates the broad scope and capabilities of the program; for example, it includes translations of intercepted French messages (see pages 8-9).

Document 43 : Admiral Tagaki Diary Entry for July 20, 1945

Source: Takashi Itoh, ed.,  Sokichi Takagi: Nikki to Joho  [Sokichi Takagi: Diary and Documents] (Tokyo, Japan: Misuzu-Shobo, 2000), 916-917 [Translation by Hikaru Tajima]

In 1944 Navy minister Mitsumasa Yonai ordered rear admiral Sokichi Takagi to go on sick leave so that he could undertake a secret mission to find a way to end the war. Tagaki was soon at the center of a cabal of Japanese defense officials, civil servants, and academics, which concluded that, in the end, the emperor would have to “impose his decision on the military and the government.” Takagi kept a detailed account of his activities, part of which was in diary form, the other part of which he kept on index cards. The material reproduced here gives a sense of the state of play of Foreign Minister Togo’s attempt to secure Soviet mediation. Hasegawa cited it and other documents to make a larger point about the inability of the Japanese government to agree on “concrete” proposals to negotiate an end to the war. [39]

The last item discusses Japanese contacts with representatives of the Office of Strategic Services (OSS) in Switzerland. The reference to “our contact” may refer to Bank of International Settlements economist Pers Jacobbson who was in touch with Japanese representatives to the Bank as well as Gero von Gävernitz, then on the staff, but with non-official cover, of OSS station chief Allen Dulles. The contacts never went far and Dulles never received encouragement to pursue them. [40]

V. The Trinity Test

Document 44 : Letter from Commissar of State Security First Rank, V. Merkulov, to People’s Commissar for Internal Affairs L. P. Beria, 10 July 1945, Number 4305/m, Top Secret (translation by Anna Melyaskova)

Source:  L.D. Riabev, ed.,  Atomnyi Proekt SSSR  (Moscow: izd MFTI, 2002), Volume 1, Part 2, 335-336

This 10 July 1945 letter from NKVD director V. N. Merkulov to Beria is an example of Soviet efforts to collect inside information on the Manhattan Project, although not all the detail was accurate. Merkulov reported that the United States had scheduled the test of a nuclear device for that same day, although the actual test took place 6 days later. According to Merkulov, two fissile materials were being produced: element-49 (plutonium), and U-235; the test device was fueled by plutonium. The Soviet source reported that the weight of the device was 3 tons (which was in the ball park) and forecast an explosive yield of 5 kilotons. That figure was based on underestimates by Manhattan Project scientists: the actual yield of the test device was 20 kilotons.

As indicated by the L.D. Riabev’s notes, it is possible that Beria’s copy of this letter ended up in Stalin’s papers. That the original copy is missing from Beria’s papers suggests that he may have passed it on to Stalin before the latter left for the Potsdam conference. [41]

Document 45 : Telegram War [Department] 33556, from Harrison to Secretary of War, July 17, 1945, Top Secret

Source: RG 77, MED Records, Top Secret Documents, File 5e (copy from microfilm)

An elated message from Harrison to Stimson reported the success of the  Trinity Test  of a plutonium implosion weapon. The light from the explosion could been seen “from here [Washington, D.C.] to “high hold” [Stimson’s estate on Long Island—250 miles away]” and it was so loud that Harrison could have heard the “screams” from Washington, D.C. to “my farm” [in Upperville, VA, 50 miles away] [42]

Document 46 : Memorandum from General L. R. Groves to Secretary of War, “The Test,” July 18, 1945, Top Secret, Excised Copy

Source: RG 77, MED Records, Top Secret Documents, File no. 4 (copy from microfilm)

General Groves prepared for Stimson, then at Potsdam, a detailed account of the Trinity test. [43]

VI. The Potsdam Conference

Document 47 : Truman’s Potsdam Diary

Source: Barton J. Bernstein, “Truman at Potsdam: His Secret Diary,”  Foreign Service Journal , July/August 1980, excerpts, used with author’s permission. [44]

Some years after Truman’s death, a hand-written diary that he kept during the Potsdam conference surfaced in his personal papers. For convenience, Barton Bernstein’s rendition is provided here but linked here are the scanned versions of Truman’s handwriting on the National Archives’ website (for 15-30 July).

The diary entries cover July 16, 17, 18, 20, 25, 26, and 30 and include Truman’s thinking about a number of issues and developments, including his reactions to Churchill and Stalin, the atomic bomb and how it should be targeted, the possible impact of the bomb and a Soviet declaration of war on Japan, and his decision to tell Stalin about the bomb. Receptive to pressure from Stimson, Truman recorded his decision to take Japan’s “old capital” (Kyoto) off the atomic bomb target list. Barton Bernstein and Richard Frank, among others, have argued that Truman’s assertion that the atomic targets were “military objectives” suggested that either he did not understand the power of the new weapons or had simply deceived himself about the nature of the targets. Another statement—“Fini Japs when that [Soviet entry] comes about”—has also been the subject of controversy over whether it meant that Truman thought it possible that the war could end without an invasion of Japan. [45]

Document 48 : Stimson Diary entries for July 16 through 25, 1945

Stimson did not always have Truman’s ear, but historians have frequently cited his diary when he was at the Potsdam conference. There Stimson kept track of S-1 developments, including news of the successful first test (see entry for July 16) and the ongoing deployments for nuclear use against Japan. When Truman received a detailed account of the test, Stimson reported that the “President was tremendously pepped up by it” and that “it gave him an entirely new feeling of confidence” (see entry for July 21). Whether this meant that Truman was getting ready for a confrontation with Stalin over Eastern Europe and other matters has also been the subject of debate.

An important question that Stimson discussed with Marshall, at Truman’s request, was whether Soviet entry into the war remained necessary to secure Tokyo’s surrender. Marshall was not sure whether that was so although Stimson privately believed that the atomic bomb would provide enough to force surrender (see entry for July 23). This entry has been cited by all sides of the controversy over whether Truman was trying to keep the Soviets out of the war. [46]  During the meeting on August 24, discussed above, Stimson gave his reasons for taking Kyoto off the atomic target list: destroying that city would have caused such “bitterness” that it could have become impossible “to reconcile the Japanese to us in that area rather than to the Russians.” Stimson vainly tried to preserve language in the Potsdam Declaration designed to assure the Japanese about “the continuance of their dynasty” but received Truman’s assurance that such a consideration could be conveyed later through diplomatic channels (see entry for July 24). Hasegawa argues that Truman realized that the Japanese would refuse a demand for unconditional surrender without a proviso on a constitutional monarchy and that “he needed Japan’s refusal to justify the use of the atomic bomb.” [47]

Document 49 : Walter Brown Diaries, July 10-August 3, 1945

Source: Clemson University Libraries, Special Collections, Clemson, SC; Mss 243, Walter J. Brown Papers, box 10, folder 12, Byrnes, James F.: Potsdam, Minutes, July-August 1945

Walter Brown, who served as special assistant to Secretary of State Byrnes, kept a diary which provided considerable detail on the Potsdam conference and the growing concerns about Soviet policy among top U.S. officials. This document is a typed-up version of the hand-written original (which Brown’s family has provided to Clemson University). That there may be a difference between the two sources becomes evident from some of the entries; for example, in the entry for July 18, 1945 Brown wrote: "Although I knew about the atomic bomb when I wrote these notes, I dared not place it in writing in my book.”

The degree to which the typed-up version reflects the original is worth investigating. In any event, historians have used information from the diary to support various interpretations. For example, Bernstein cites the entries for 20 and 24 July to argue that “American leaders did not view Soviet entry as a substitute for the bomb” but that the latter “would be so powerful, and the Soviet presence in Manchuria so militarily significant, that there was no need for actual Soviet intervention in the war.” For  Brown's diary entry of 3 August 9 1945 historians have developed conflicting interpretations (See discussion of document 57). [48]

Document 50 : “Magic” – Diplomatic Summary, War Department, Office of Assistant Chief of Staff, G-2, No. 1214 – July 22, 1945, Top Secret Ultra

This “Magic” summary includes messages from both Togo and Sato. In a long and impassioned message, the latter argued why Japan must accept defeat: “it is meaningless to prove one’s devotion [to the Emperor] by wrecking the State.” Togo rejected Sato’s advice that Japan could accept unconditional surrender with one qualification: the “preservation of the Imperial House.” Probably unable or unwilling to take a soft position in an official cable, Togo declared that “the whole country … will pit itself against the enemy in accordance with the Imperial Will as long as the enemy demands unconditional surrender.”

Document 51 : Forrestal Diary Entry, July 24, 1945, “Japanese Peace Feelers”

Source: Naval Historical Center, Operational Archives, James Forrestal Diaries

Secretary of the Navy James Forrestal was a regular recipient of “Magic” intercept reports; this substantial entry reviews the dramatic Sato-Togo exchanges covered in the 22 July “Magic” summary (although Forrestal misdated Sato’s cable as “first of July” instead of the 21 st ). In contrast to Alperovitz’s argument that Forrestal tried to modify the terms of unconditional surrender to give the Japanese an out, Frank sees Forrestal’s account of the Sato-Togo exchange as additional evidence that senior U.S. officials understood that Tokyo was not on the “cusp of surrender.”  [49]

Document 52 : Davies Diary entry for July 29, 1945

S ource: Joseph E. Davies Papers, Library of Congress, Manuscripts Division, box 19, 29 July 1945

Having been asked by Truman to join the delegation to the Potsdam conference, former-Ambassador Davies sat at the table with the Big Three throughout the discussions. This diary entry has figured in the argument that Byrnes believed that the atomic bomb gave the United States a significant advantage in negotiations with the Soviet Union. Plainly Davies thought otherwise. [50]

VII. Debates among the Japanese – Late July/Early August 1945

Document 53 : “Magic” – Diplomatic Summary, War Department, Office of Assistant Chief of Staff, G-2, No. 1221- July 29, 1945, Top Secret Ultra

In the  Potsdam Declaration  the governments of China, Great Britain, and the United States) demanded the “unconditional surrender of all Japanese armed forces. “The alternative is prompt and utter destruction.” The next day, in response to questions from journalists about the government’s reaction to the ultimatum, Prime Minister Suzuki apparently said that “We can only ignore [ mokusatsu ] it. We will do our utmost to complete the war to the bitter end.” That, Bix argues, represents a “missed opportunity” to end the war and spare the Japanese from continued U.S. aerial attacks. [51]  Togo’s private position was more nuanced than Suzuki’s; he told Sato that “we are adopting a policy of careful study.” That Stalin had not signed the declaration (Truman and Churchill did not ask him to) led to questions about the Soviet attitude. Togo asked Sato to try to meet with Soviet Foreign Minister Molotov as soon as possible to “sound out the Russian attitude” on the declaration as well as Japan’s end-the-war initiative. Sato cabled Togo earlier that he saw no point in approaching the Soviets on ending the war until Tokyo had “concrete proposals.” “Any aid from the Soviets has now become extremely doubtful.”

Document 54 : “Magic” – Diplomatic Summary, War Department, Office of Assistant Chief of Staff, G-2, No. 1222 – July 30, 1945, Top Secret Ultra

This report included an intercept of a message from Sato reporting that it was impossible to see Molotov and that unless the Togo had a “concrete and definite plan for terminating the war” he saw no point in attempting to meet with him.

Document 55 : “Magic” – Diplomatic Summary, War Department, Office of Assistant Chief of Staff, G-2, No. 1225 – August 2, 1945, Top Secret Ultra

An intercepted message from Togo to Sato showed that Tokyo remained interested in securing Moscow’s good office but that it “is difficult to decide on concrete peace conditions here at home all at once.” “[W]e are exerting ourselves to collect the views of all quarters on the matter of concrete terms.” Barton Bernstein, Richard Frank, and Tsuyoshi Hasegawa, among others, have argued that the “Magic” intercepts from the end of July and early August show that the Japanese were far from ready to surrender. According to Herbert Bix, for months Hirohito had believed that the “outlook for a negotiated peace could be improved if Japan fought and won one last decisive battle,” thus, he delayed surrender, continuing to “procrastinate until the bomb was dropped and the Soviets attacked.” [52]

Document 56 : “Magic” – Diplomatic Summary, War Department, Office of Assistant Chief of Staff, G-2, No. 1226 - August 3, 1945, Top Secret Ultra

This summary included intercepts of Japanese diplomatic reporting on the Soviet buildup in the Far East as well as a naval intelligence report on Anglo-American discussions of U.S. plans for the invasion of Japan. Part II of the summary includes the rest of Togo’s 2 August cable which instructed Sato to do what he could to arrange an interview with Molotov.

Document 57 : Walter Brown Meeting Notes, August 3, 1945

Historians have used this item in the papers of Byrne’s aide, Walter Brown, to make a variety of points. Richard Frank sees this brief discussion of Japan’s interest in Soviet diplomatic assistance as crucial evidence that Admiral Leahy had been sharing “MAGIC” information with President Truman. He also points out that Truman and his colleagues had no idea what was behind Japanese peace moves, only that Suzuki had declared that he would “ignore” the Potsdam Declaration. Alperovitz, however, treats it as additional evidence that “strongly suggests” that Truman saw alternatives to using the bomb. [53]

Document 58 : “Magic” – Far East Summary, War Department, Office of Assistant Chief of Staff, G-2, no. 502, 4 August 1945

Source: RG 457, Summaries of Intercepted Japanese Messages (“Magic” Far East Summary, March 20, 1942 – October 2, 1945), box 7, SRS 491-547

This “Far East Summary” included reports on the Japanese Army’s plans to disperse fuel stocks to reduce vulnerability to bombing attacks, the text of a directive by the commander of naval forces on “Operation Homeland,” the preparations and planning to repel a U.S. invasion of Honshu, and the specific identification of army divisions located in, or moving into, Kyushu. Both Richard Frank and Barton Bernstein have used intelligence reporting and analysis of the major buildup of Japanese forces on southern Kyushu to argue that U.S. military planners were so concerned about this development that by early August 1945 they were reconsidering their invasion plans. [54]

Document 59 : “Magic” – Diplomatic Summary, War Department, Office of Assistant Chief of Staff, G-2, No. 1228 – August 5, 1945, Top Secret Ultra

This summary included several intercepted messages from Sato, who conveyed his despair and exasperation over what he saw as Tokyo’s inability to develop terms for ending the war: “[I]f the Government and the Military dilly-dally in bringing this resolution to fruition, then all Japan will be reduced to ashes.” Sato remained skeptical that the Soviets would have any interest in discussions with Tokyo: “it is absolutely unthinkable that Russia would ignore the Three Power Proclamation and then engage in conversations with our special envoy.”

VIII. The Execution Order

Documents 60a-d: Framing the Directive for Nuclear Strikes:

60A . Cable VICTORY 213 from Marshall to Handy, July 22, 1945, Top Secret

60B . Memorandum from Colonel John Stone to General Arnold, “Groves Project,” 24 July 1945, Top Secret

60C . Cable WAR 37683 from General Handy to General Marshal, enclosing directive to General Spatz, July 24, 1945, Top Secret

60D . Cable VICTORY 261 from Marshall to General Handy, July 25, 1945, 25 July 1945, Top Secret

60E . General Thomas T. Handy to General Carl Spaatz, July 26, 1945, Top Secret

Source: RG 77, MED Records, Top Secret Documents, Files no. 5b and 5e ((copies from microfilm)

Top Army Air Force commanders may not have wanted to take responsibility for the first use of nuclear weapons on urban targets and sought formal authorization from Chief of Staff Marshall who was then in Potsdam. [55]  On 22 July Marshall asked Deputy Chief of Staff Thomas Handy to prepare a draft; General Groves wrote one which went to Potsdam for Marshall’s approval. Colonel John Stone, an assistant to commanding General of the Army Air Forces Henry H. “Hap” Arnold, had just returned from Potsdam and updated his boss on the plans as they had developed. On 25 July Marshall informed Handy that Secretary of War Stimson had approved the text; that same day, Handy signed off on a directive which ordered the use of atomic weapons on Japan, with the first weapon assigned to one of four possible targets—Hiroshima, Kokura, Niigata, or Nagasaki. “Additional bombs will be delivery on the [targets] as soon as made ready by the project staff.”

Document 61 : Memorandum from Major General L. R. Groves to Chief of Staff, July 30, 1945, Top Secret, Sanitized Copy

Source: RG 77, MED Records, Top Secret Documents, File no. 5

With more information on the Alamogordo test available, Groves provided Marshall with detail on the destructive power of atomic weapons. Barton J. Bernstein has observed that Groves’ recommendation that troops could move into the “immediate explosion area” within a half hour demonstrates the prevalent lack of top-level knowledge of the dangers of nuclear weapons effects. [56]  Groves also provided the schedule for the delivery of the weapons: the components of the gun-type bomb to be used on Hiroshima had arrived on Tinian, while the parts of the second weapon to be dropped were leaving San Francisco. By the end of November over ten weapons would be available, presumably in the event the war had continued.

Documents 62A-C: Weather delays

62A . CG 313 th  Bomb Wing, Tinian cable APCOM 5112 to War Department, August 3, 1945, Top Secret

62B . CG 313 th  Bomb Wing, Tinian cable APCOM 5130 to War Department, August 4, 1945, Top Secret

62C . CG 313 th  Bomb Wing, Tinian cable APCOM 5155 to War Department, August 4, 1945, Top Secret

Source: RG 77, Tinian Files, April-December 1945, box 21 (copies courtesy of Barton Bernstein)

The Hiroshima “operation” was originally slated to begin in early August depending on local conditions. As these cables indicate, reports of unfavorable weather delayed the plan. The second cable on 4 August shows that the schedule advanced to late in the evening of 5 August. The handwritten transcriptions are on the original archival copies.

IX. The First Nuclear Strikes and their Impact

Document 63 : Memorandum from General L. R. Groves to the Chief of Staff, August 6, 1945, Top Secret

Source: RG 77, MED Records, Top Secret Documents, File no. 5b (copy from microfilm)

Two days after the bombing of Hiroshima, Groves provided Chief of Staff Marshall with a report which included messages from Captain William S. Parsons and others about the impact of the detonation which, through prompt radiation effects, fire storms, and blast effects, immediately killed at least 70,000, with many dying later from radiation sickness and other causes. [57]

How influential the atomic bombings of Hiroshima and later Nagasaki compared to the impact of the Soviet declaration of war were to the Japanese decision to surrender has been the subject of controversy among historians. Sadao Asada emphasizes the shock of the atomic bombs, while Herbert Bix has suggested that Hiroshima and the Soviet declaration of war made Hirohito and his court believe that failure to end the war could lead to the destruction of the imperial house. Frank and Hasegawa divide over the impact of the Soviet declaration of war, with Frank declaring that the Soviet intervention was “significant but not decisive” and Hasegawa arguing that the two atomic bombs “were not sufficient to change the direction of Japanese diplomacy. The Soviet invasion was.” [58]

Document 64 : Walter Brown Diary Entry, 6 August 1945

Source:  Clemson University Libraries, Special Collections, Clemson, SC; Mss 243, Walter J. Brown Papers, box 68, folder 13, “Transcript/Draft B

Returning from the Potsdam Conference, sailing on the  U.S.S. Augusta , Truman learned about the atomic bombing of Hiroshima and announced it twice, first to those in the wardroom (socializing/dining area for commissioned officers), and then to the sailors’ mess. Still unaware of radiation effects, Truman emphasized the explosive yield. Later, he met with Secretary of State Byrnes and they discussed the Manhattan Project’s secrecy and the huge expenditures. Truman, who had been chair of the Senate Special Committee to Investigate the National Defense Program, said that “only on the appeal of Secretary of War Stimson did he refrain and let the War Department continue with the experiment unmolested.”

Document 65 : Directive from the Supreme Command Headquarters to the Commander-in-Chief of the Soviet Forces in the Far East on the Start of Combat Operations, No. 11122, Signed by [Communist Party General Secretary Joseph] Stalin and [Chief of General Staff A.I.] Antonov, 7 August 1945 (translation by Anna Melyakova)

Source: V. A. Zolotarev, ed.,  Sovetsko-Iaponskaia Voina 1945 Goda: Istoriia Voenno-Politicheskogo Protivoborstva Dvukh Derzhav v 30–40e Gody ( Moscow: Terra, 1997 and 2000), Vol. 7 (1), 340-341.

To keep his pledge at Yalta to enter the war against Japan and to secure the territorial concessions promised at the conference (e.g., Soviet annexation of the Kuriles and southern Sakhalin and a Soviet naval base at Port Arthur, etc.) Stalin considered various dates to schedule an attack. By early August he decided that 9-10 August 1945 would be the best dates for striking Japanese forces in Manchuria. In light of Japan’s efforts to seek Soviet mediation, Stalin wanted to enter the war quickly lest Tokyo reach a compromise peace with the Americans and the British at Moscow’s expense. But on 7 August, Stalin changed the instructions: the attack was to begin the next day. According to David Holloway, “it seems likely that the atomic bombing of Hiroshima the day before that impelled [Stalin] to speed up Soviet entry into the war” and “secure the gains promised at Yalta.” [59]

Document 66 : Memorandum of Conversation, “Atomic Bomb,” August 7, 1945

Source: Library of Congress Manuscript Division, Papers of W. Averell Harriman, box 181, Chron File Aug 5-9, 1945.

The Soviets already knew about the U.S. atomic project from espionage sources in the United States and Britain so Molotov’s comment to Ambassador Harriman about the secrecy surrounding the U.S. atomic project can be taken with a grain of salt, although the Soviets were probably unaware of specific plans for nuclear use.

Documents 67A-B:  Early High-level Reactions to the Hiroshima Bombing

67A : Cabinet Meeting and Togo's Meeting with the Emperor, August 7-8, 1945 Source: Gaimusho (Ministry of Foreign Affairs) ed.  Shusen Shiroku  (The Historical Records of the End of the War), annotated by Jun Eto, volume 4, 57-60 [Excerpts] [Translation by Toshihiro Higuchi]

67B : Admiral Tagaki Diary Entry for Wednesday, August 8 , 1945

Source: Takashi Itoh, ed.,  Sokichi Takagi: Nikki to Joho  [Sokichi Takagi: Diary and Documents] (Tokyo, Japan: Misuzu-Shobo, 2000), 923-924 [Translation by Hikaru Tajima]

Excerpts from the Foreign Ministry's compilation about the end of the war show how news of the bombing reached Tokyo as well as how Foreign Minister's Togo initially reacted to reports about Hiroshima. When he learned of the atomic bombing from the Domei News Agency, Togo believed that it was time to give up and advised the cabinet that the atomic attack provided the occasion for Japan to surrender on the basis of the Potsdam Declaration. Togo could not persuade the cabinet, however, and the Army wanted to delay any decisions until it had learned what had happened to Hiroshima. When the Foreign Minister met with the Emperor, Hirohito agreed with him; he declared that the top priority was an early end to the war, although it would be acceptable to seek better surrender terms--probably U.S. acceptance of a figure-head emperor--if it did not interfere with that goal. In light of those instructions, Togo and Prime Minister Suzuki agreed that the Supreme War Council should meet the next day.  [59a]

An entry from Admiral Tagaki's diary for August 8 conveys more information on the mood in elite Japanese circles after Hiroshima, but before the Soviet declaration of war and the bombing of Nagasaki. Seeing the bombing of Hiroshima as a sign of a worsening situation at home, Tagaki worried about further deterioration. Nevertheless, his diary suggests that military hard-liners were very much in charge and that Prime Minister Suzuki was talking tough against surrender, by evoking last ditch moments in Japanese history and warning of the danger that subordinate commanders might not obey surrender orders. The last remark aggravated Navy Minister Yonai who saw it as irresponsible. That the Soviets had made no responses to Sato's request for a meeting was understood as a bad sign; Yonai realized that the government had to prepare for the possibility that Moscow might not help. One of the visitors mentioned at the beginning of the entry was Iwao Yamazaki who became Minister of the Interior in the next cabinet.

Document 68 : Navy Secretary James Forrestal to President Truman, August 8, 1945

General Douglas MacArthur had been slated as commander for military operations against Japan’s mainland, this letter to Truman from Forrestal shows that the latter believed that the matter was not settled. Richard Frank sees this as evidence of the uncertainty felt by senior officials about the situation in early August; Forrestal would not have been so “audacious” to take an action that could ignite a “political firestorm” if he “seriously thought the end of the war was near.”

Document 69 : Memorandum of Conversation, “Far Eastern War and General Situation,” August 8, 1945, Top Secret

Source: Library of Congress Manuscript Division, Papers of W. Averell Harriman, box 181, Chron File Aug 5-9, 1945

Shortly after the Soviets declared war on Japan, in line with commitments made at the Yalta and Potsdam conferences, Ambassador Harriman met with Stalin, with George Kennan keeping the U.S. record of the meeting. After Stalin reviewed in considerable detail, Soviet military gains in the Far East, they discussed the possible impact of the atomic bombing on Japan’s position (Nagasaki had not yet been attacked) and the dangers and difficulty of an atomic weapons program. According to Hasegawa, this was an important, even “startling,” conversation: it showed that Stalin “took the atomic bomb seriously”; moreover, he disclosed that the Soviets were working on their own atomic program. [60]

Document 70 : Entries for 8-9 August, Robert P. Meiklejohn Diary

Source: W.A. Harriman Papers, Library of Congress, box 211 , Robert Pickens Meiklejohn World War II Diary At London and Moscow March 10, 1941-February 14, 1946 , Volume II (Privately printed, 1980 [Printed from hand-written originals]) (Reproduced with permission)

Robert P. Meiklejohn, who worked as Ambassador W. A. Harriman’s administrative assistant at the U.S. Embassies in Moscow and London during and after World War II, kept a detailed diary of his experiences and observations. The entries for 8 and 9 August, prepared in light of the bombing of Hiroshima, include discussion of the British contribution to the Manhattan Project, Harriman (“his nibs’”) report on his meeting with Molotov about the Soviet declaration of war, and speculation about the impact of the bombing of Hiroshima on the Soviet decision. According to Meiklejohn, “None of us doubt that the atomic bomb speeded up the Soviets’ declaration of war.”

Document 71 : Memorandum of Conference with the President, August 8, 1945 at 10:45 AM

At their first meeting after the dropping of the bomb on Hiroshima, Stimson briefed Truman on the scale of the destruction, with Truman recognizing the “terrible responsibility” that was on his shoulders. Consistent with his earlier attempts, Stimson encouraged Truman to find ways to expedite Japan’s surrender by using “kindness and tact” and not treating them in the same way as the Germans. They also discussed postwar legislation on the atom and the pending Henry D. Smyth report on the scientific work underlying the Manhattan project and postwar domestic controls of the atom.

Documents 72A-C: The Attack on Nagasaki:

72A . Cable APCOM 5445 from General Farrell to O’Leary [Groves assistant], August 9, 1945, Top Secret

72B . COMGENAAF 8 cable CMDW 576 to COMGENUSASTAF, for General Farrell, August 9, 1945, Top secret

72C . COMGENAAF 20 Guam cable AIMCCR 5532 to COMGENUSASTAF Guam, August 10, 1945, Top Secret

Source: RG 77, Tinian Files, April-December 1945, box 20, Envelope G Tinian Files, Top Secret

The prime target for the second atomic attack was Kokura, which had a large army arsenal and ordnance works, but various problems ruled that city out; instead, the crew of the B-29 that carried “Fat Man” flew to an alternate target at Nagasaki. These cables are the earliest reports of the mission; the bombing of Nagasaki killed immediately at least 39,000 people, with more dying later. According to Frank, the “actual total of deaths due to the atomic bombs will never be known,” but the “huge number” ranges somewhere between 100,000 and 200,000 people. Barton J. Bernstein and Martin Sherwin have argued that if top Washington policymakers had kept tight control of the delivery of the bomb instead of delegating it to Groves the attack on Nagasaki could have been avoided. The combination of the first bomb and the Soviet declaration of war would have been enough to induce Tokyo’s surrender. By contrast, Maddox argues that Nagasaki was necessary so that Japanese “hardliners” could not “minimize the first explosion” or otherwise explain it away. [61]

Documents 73A-B: Ramsey Letter from Tinian Island

73A : Letter from Norman Ramsey to J. Robert Oppenheimer, undated [mid-August 1945], Secret, excerpts Source: Library of Congress, J. Robert Oppenheimer Papers, box 60, Ramsey, Norman

73B : Transcript of the letter prepared by editor.

Ramsey, a physicist, served as deputy director of the bomb delivery group, Project Alberta. This personal account, written on Tinian, reports his fears about the danger of a nuclear accident, the confusion surrounding the Nagasaki attack, and early Air Force thinking about a nuclear strike force.

X. Toward Surrender

Document 74 : “Magic” – Far East Summary, War Department, Office of Assistant Chief of Staff, G-2, no. 507, August 9, 1945

Within days after the bombing of Hiroshima, U.S. military intelligence intercepted Japanese reports on the destruction of the city. According to an “Eyewitness Account (and Estimates Heard) … In Regard to the Bombing of Hiroshima”: “Casualties have been estimated at 100,000 persons.”

Document 75 : “Hoshina Memorandum” on the Emperor’s “Sacred Decision [ go-seidan] ,” 9-10 August, 1945

Source: Zenshiro Hoshina,  Daitoa Senso Hishi: Hoshina Zenshiro Kaiso-roku  [Secret History of the Greater East Asia War: Memoir of Zenshiro Hoshina] (Tokyo, Japan: Hara-Shobo, 1975), excerpts from Section 5, “The Emperor made  go-seidan  [= the sacred decision] – the decision to terminate the war,” 139-149 [translation by Hikaru Tajima]

Despite the bombing of Hiroshima, the Soviet declaration of war, and growing worry about domestic instability, the Japanese cabinet (whose decisions required unanimity) could not form a consensus to accept the Potsdam Declaration. Members of the Supreme War Council—“the Big Six” [62] —wanted the reply to Potsdam to include at least four conditions (e.g., no occupation, voluntary disarmament); they were willing to fight to the finish. The peace party, however, deftly maneuvered to break the stalemate by persuading a reluctant emperor to intervene. According to Hasegawa, Hirohito had become convinced that the preservation of the monarchy was at stake. Late in the evening of 9 August, the emperor and his advisers met in the bomb shelter of the Imperial Palace.

Zenshiro Hoshina, a senior naval official, attended the conference and prepared a detailed account. With Prime Minister Suzuki presiding, each of the ministers had a chance to state their views directly to Hirohito. While Army Minister Anami tacitly threatened a coup (“civil war”), the emperor accepted the majority view that the reply to the Potsdam declaration should include only one condition not the four urged by “Big Six.” Nevertheless, the condition that Hirohito accepted was not the one that foreign minister Togo had brought to the conference. What was at stake was the definition of the  kokutai  (national policy). Togo’s proposal would have been generally consistent with a constitutional monarchy because it defined the  kokutai  narrowly as the emperor and the imperial household. What Hirohito accepted, however, was a proposal by the extreme nationalist Kiichiro Hiranuma which drew upon prevailing understandings of the  kokutai : the “mythical notion” that the emperor was a living god. “This was the affirmation of the emperor’s theocratic powers, unencumbered by any law, based on Shinto gods in antiquity, and totally incompatible with a constitutional monarchy.” Thus, the Japanese response to the Potsdam declaration opposed “any demand which prejudices the prerogatives of his Majesty as a sovereign ruler.” This proved to be unacceptable to the Truman administration. [63]

Document 76 :“Magic’ – Far East Summary, War Department, Office of Assistant Chief of Staff, G-2, no. 508, August 10, 1945

More intercepted messages on the bombing of Hiroshima.

Documents 77A-B: The First Japanese Offer Intercepted

77A . “Magic” – Diplomatic Summary, War Department, Office of Assistant Chief of Staff, G-2, No. 1233 – August 10, 1945, Top Secret Ultra

77B . Translation of intercepted Japanese messages, circa 10 August 10, 1945, Top Secret Ultra

The first Japanese surrender offer was intercepted shortly before Tokyo broadcast it. This issue of the diplomatic summary also includes Togo’s account of his notification of the Soviet declaration of war, reports of Soviet military operations in the Far East, and intercepts of French diplomatic traffic. A full translation of the surrender offer was circulated separately. The translations differ but they convey the sticking point that prevented U.S. acceptance: Tokyo’s condition that the allies not make any “demand which prejudices the prerogatives of His Majesty as a sovereign ruler.”

Document 78 : Diary Entry, Friday, August 10, 1945, Henry Wallace Diary

Source: Papers of Henry A. Wallace, Special Collections Department, University of Iowa Libraries, Iowa City, Iowa (copy courtesy of Special Collections Department)

Note: The second page of the diary entry includes a newspaper clipping of the Associated Press’s transmission of the Byrnes note. Unfortunately, AP would not authorize the Archive to reproduce this item without payment. Therefore, we are publishing an excised version of the entry, with a link to the  Byrnes note .

Secretary of Commerce (and former Vice President) Henry Wallace provided a detailed report on the cabinet meeting where Truman and his advisers discussed the Japanese surrender offer, Russian moves into Manchuria, and public opinion on “hard” surrender terms. With Japan close to capitulation, Truman asserted presidential control and ordered a halt to atomic bombings. Barton J. Bernstein has suggested that Truman’s comment about “all those kids” showed his belated recognition that the bomb caused mass casualties and that the target was not purely a military one. [64]

Document 79 : Entries for 10-11 August, Robert P. Meiklejohn Diary

In these entries, Meiklejohn discussed how he and others in the Moscow Embassy learned about the bombing of Nagasaki from the “OWI Bulletin.” Entries for 10 and 11 August cover discussion at the Embassy about the radio broadcast announcing that Japan would surrender as long the Emperor’s status was not affected. Harriman opined that “surrender is in the bag” because of the Potsdam Declaration’s provision that the Japanese could “choose their own form of government, which would probably include the Emperor.” Further, “the only alternative to the Emperor is Communism,” implying that an official role for the Emperor was necessary to preserve social stability and prevent social revolution.

Document 80 : Stimson Diary Entries, Friday and Saturday, August 10 and 11, 1945

Stimson’s account of the events of 10 August focused on the debate over the reply to the Japanese note, especially the question of the Emperor’s status.  The U.S. reply , drafted during the course of the day, did not explicitly reject the note but suggested that any notion about the “prerogatives” of the Emperor would be superceded by the concept that all Japanese would be “Subject to the Supreme Commander of the Allied Powers.” The language was ambiguous enough to enable Japanese readers, upon Hirohito’s urging, to believe that they could decide for themselves the Emperor’s future role. Stimson accepted the language believing that a speedy reply to the Japanese would allow the United States to “get the homeland into our hands before the Russians could put in any substantial claim to occupy and help rule it.” If the note had included specific provision for a constitutional monarchy, Hasegawa argues, it would have “taken the wind out of the sails” of the military faction and Japan might have surrendered several days earlier, on August 11 or 12 instead of August 14. [65]

Document 81 : Entries from Walter Brown Diary, 10-11 August 1945

Source:  Clemson University Libraries, Special Collections, Clemson, SC; Mss 243, Walter Brown Papers, box 68, folder 13, “Transcript/Draft B

Brown recounted Byrnes’ debriefing of the 10 August White House meeting on the Japanese peace offer, an account which differed somewhat from that in the Stimson diary .  According to what Byrnes told Brown, Truman, Stimson, and Leahy favored accepting the Japanese note, but Byrnes objected that the United States should “go [no] further than we were willing to go at Potsdam.” Stimson’s account of the meeting noted Byrnes’ concerns (“troubled and anxious”) about the Japanese note and implied that he (Stimson) favored accepting it, but did not picture the debate as starkly as Browns's did.

Document 82 : General L. R. Groves to Chief of Staff George C. Marshall,  August 10, 1945, Top Secret, with a hand-written note by General Marshall

Source: George C. Marshall Papers, George C. Marshall Library, Lexington, VA (copy courtesy of Barton J. Bernstein)

Groves informed General Marshall that he was making plans for the use of a third atomic weapon sometime after 17 August, depending on the weather. With Truman having ordered a halt to the atomic bombings [See document 78], Marshall wrote on Grove's memo that the bomb was “not to be released over Japan without express authority from the President.”

Document 83 : Memorandum of Conversation, “Japanese Surrender Negotiations,” August 10, 1945, Top Secret

Source: Library of Congress Manuscript Division, Papers of W. Averell Harriman, box 181, Chron File Aug 10-12, 1945

Japan’s prospective surrender was the subject of detailed discussion between Harriman, British Ambassador Kerr, and Soviet Foreign Minister Molotov during the evening of August 10 (with a follow-up meeting occurring at 2 a.m.). In the course of the conversation, Harriman received a message from Washington that included the proposed U.S. reply and a request for Soviet support of the reply. After considerable pressure from Harriman, the Soviets signed off on the reply but not before tensions surfaced over the control of Japan--whether Moscow would have a Supreme Commander there as well. This marked the beginning of a U.S.-Soviet “tug of war” over occupation arrangements for Japan. [66]

Document 84 : Admiral Tagaki Diary Entry for 12 August [1945] Source: Takashi Itoh, ed.,  Sokichi Takagi: Nikki to Joho  [Sokichi Takagi: Diary and Documents] (Tokyo, Japan: Misuzu-Shobo, 2000), 926-927 [Translation by Hikaru Tajima]

As various factions in the government maneuvered on how to respond to the Byrnes note, Navy Minister Yonai and Admiral Tagaki discussed the latest developments. Yonai was upset that Chief of Staff Yoshijiro Umezu and naval chief Suemu Toyada had sent the emperor a memorandum arguing that acceptance of the Brynes note would “desecrate the emperor’s dignity” and turn Japan into virtually a “slave nation.” The emperor chided Umezu and Toyoda for drawing hasty conclusions; in this he had the support of Yonai, who also dressed them down. As Yonai explained to Tagaki, he had also confronted naval vice Chief Takijiro Onishi to make sure that he obeyed any decision by the Emperor. Yonai made sure that Takagi understood his reasons for bringing the war to an end and why he believed that the atomic bomb and the Soviet declaration of war had made it easier for Japan to surrender. [67]

Document 85 : Memorandum from Major General Clayton Bissell, Assistant Chief of Staff, G-2, for the Chief of Staff, “Estimate of Japanese Situation for Next 30 Days,” August 12, 1945, Top Secret

Source: National Archives, RG 165, Army Operations OPD, Executive Files 1940-1945, box 12, Exec #2

Not altogether certain that surrender was imminent, Army intelligence did not rule out the possibility that Tokyo would try to “drag out the negotiations” or reject the Byrnes proposal and continue fighting. If the Japanese decided to keep fighting, G-2 opined that “Atomic bombs will not have a decisive effect in the next 30 days.” Richard Frank has pointed out that this and other documents indicate that high level military figures remained unsure as to how close Japan really was to surrender.

Document 86 : The Cabinet Meeting over the Reply to the Four Powers (August 13)

Source:  Gaimusho [Ministry of Foreign Affairs], ed., Shusen Shiroku [Historical Record of the End of the War] (Tokyo: Hokuyosha, 1977-1978), vol. 5, 27-35 [Translated by Toshihiro Higuchi]

The Byrnes Note did not break the stalemate at the cabinet level. An account of the cabinet debates on August 13 prepared by Information Minister Toshiro Shimamura showed the same divisions as before; Anami and a few other ministers continued to argue that the Allies threatened the  kokutai  and that setting the four conditions (no occupation, etc.) did not mean that the war would continue. Nevertheless, Anami argued, “We are still left with some power to fight.” Suzuki, who was working quietly with the peace party, declared that the Allied terms were acceptable because they gave a “dim hope in the dark” of preserving the emperor. At the end of the meeting, he announced that he would report to Hirohito and ask him to make another “Sacred Judgment”. Meanwhile, junior Army officers plotted a coup to thwart the plans for surrender. [68]

Document 87 : Telephone conversation transcript, General Hull and Colonel Seaman [sic] – 1325 – 13 Aug 45, Top Secret

Source: George C. Marshall Library, Lexington, VA, George C. Marshall Papers (copy courtesy of Barton J. Bernstein)

While Truman had rescinded the order to drop nuclear bombs, the war was not yet over and uncertainty about Japan’s next step motivated war planner General John E. Hull (assistant chief of staff for the War Department’s Operations Division), and one of Groves’ associates, Colonel L. E. Seeman, to continue thinking about further nuclear use and its relationship to a possible invasion of Japan. As Hull explained, “should we not concentrate on targets that will be of greatest assistance to an invasion rather than industry, morale, psychology, etc.” “Nearer the tactical use”, Seaman agreed and they discussed the tactics that could be used for beach landings. In 1991 articles, Barton Bernstein and Marc Gallicchio used this and other evidence to develop the argument that concepts of tactical nuclear weapons use first came to light at the close of World War II. [69]

Document 88 : “Magic” – Diplomatic Summary, War Department, Office of Assistant Chief of Staff, G-2, No. 1236 – August 13, 1945, Top Secret Ultra

The dropping of two atomic bombs, the tremendous destruction caused by U.S. bombing, and the Soviet declaration of war notwithstanding, important elements of the Japanese Army were unwilling to yield, as was evident from intercepted messages dated 12 and 13 August. Willingness to accept even the “destruction of the Army and Navy” rather than surrender inspired the military coup that unfolded and failed during the night of 14 August.

Document 89 : “The Second  Sacred Judgment”, August 14, 1945

Source :   Hiroshi [Kaian) Shimomura, S husenki [Account of the End of the War]  (Tokyo, Kamakura Bunko, [1948], 148-152 [Translated by Toshihiro Higuchi]

Frightened by the rapid movement of Soviet forces into Manchuria and worried that the army might launch a coup, the peace party set in motion a plan to persuade Hirohito to meet with the cabinet and the “Big Six” to resolve the stalemate over the response to the Allies. Japan was already a day late in responding to the Byrnes Note and Hirohito agreed to move quickly. At 10:50 a.m., he met with the leadership at the bomb shelter in his palace. This account, prepared by Director of Information Shimomura, conveys the drama of the occasion (as well as his interest in shifting the blame for the debacle to the Army). After Suzuki gave the war party--Umeda, Toyoda, and Anami--an opportunity to present their arguments against accepting the Byrnes Note, he asked the emperor to speak. 

  Hirohito asked the leadership to accept the Note, which he believed was “well intentioned” on the matter of the “national polity” (by leaving open a possible role for the Emperor).  Arguing that continuing the war would reduce the nation “to ashes,” his words about “bearing the unbearable” and sadness over wartime losses and suffering prefigured the language that Hirohito would use in his public announcement the next day. According to Bix, “Hirohito's language helped to transform him from a war to a peace leader, from a cold, aloof monarch to a human being who cared for his people” but “what chiefly motivated him … was his desire to save a politically empowered throne with himself on it.” [70]

Hirohito said that he would make a recording of the surrender announcement so that the nation could hear it. That evening army officers tried to seize the palace and find Hirohito’s recording, but the coup failed. Early the next day, General Anami committed suicide. On the morning of August 15, Hirohito broadcast the message to the nation (although he never used the word “surrender”). A few weeks later, on September 2, 1945 Japanese representatives signed surrender documents on the USS  Missouri , in Tokyo harbor. [71]

Document 90 : “Magic” – Far East Summary, War Department, Office of Assistant Chief of Staff, G-2, no. 515, August 18, 1945

This summary includes an intercepted account of the destruction of Nagasaki.

Document 91 :Washington Embassy Telegram 5599 to Foreign Office, 14 August 1945, Top Secret [72]

Source: The British National Archives, Records of the Foreign and Commonwealth Office,  FO 800/461

With the Japanese surrender announcement not yet in, President Truman believed that another atomic bombing might become necessary. After a White House meeting on 14 August, British Minister John Balfour reported that Truman had “remarked sadly that he now had no alternative but to order an atomic bomb to be dropped on Tokyo.” This was likely emotional thinking spurred by anxiety and uncertainty. Truman was apparently not considering the fact that Tokyo was already devastated by fire bombing and that an atomic bombing would have killed the Emperor, which would have greatly complicated the process of surrender. Moreover, he may not have known that the third bomb was still in the United States and would not be available for use for nearly another week. [73]  As it turned out, a few hours later, at 4:05 p.m., the White House received the Japanese surrender announcement.

XI. Confronting the Problem of Radiation Poisoning

Document 92 : P.L. Henshaw and R.R. Coveyou to H.J. Curtis and K. Z. Morgan, “Death from Radiation Burns,” 24 August 1945, Confidential

Source: Department of Energy Open-Net

Two scientists at Oak Ridge’s Health Division, Henshaw and Coveyou, saw a United Press report in the Knoxville  News Sentinel  about radiation sickness caused by the bombings. Victims who looked healthy weakened, “for unknown reasons” and many died. Lacking direct knowledge of conditions in Hiroshima and Nagasaki, Henshaw and Coveyou had their own data on the biological effects of radiation and could make educated guesses. After reviewing the impact of various atomic bomb effects--blast, heat, flash radiation (prompt effects from gamma waves), and radiation from radioactive substances--they concluded that “it seems highly plausible that a great many persons were subjected to lethal and sub-lethal dosages of radiation in areas where direct blast effects were possibly non-lethal.” It was “probable,” therefore, that radiation “would produce increments to the death rate and “even more probable” that a “great number of cases of sub-lethal exposures to radiation have been suffered.” [74]

Document 93 : Memorandum of Telephone Conversation Between General Groves and Lt. Col. Rea, Oak Ridge Hospital, 9:00 a.m., August 28, 1945, Top Secret

Source: RG 77, MED Records, Top Secret Documents, File no. 5b

Despite the reports pouring in from Japan about radiation sickness among the victims of Hiroshima and Nagasaki, General Groves and Dr. Charles Rea, a surgeon who was head of the base hospital at Oak Ridge (and had no specialized knowledge about the biological effects of radiation) dismissed the reports as “propaganda”. Unaware of the findings of Health Division scientists, Groves and Rhea saw the injuries as nothing more than “good thermal burns.” [75]

Documents 94A-B: General Farrell Surveys the Destruction

94A . Cable CAX 51813 from  USS Teton  to Commander in Chief Army Forces Pacific Administration, From Farrell to Groves, September 10, 1945, Secret

94B . Cable CAX 51948 from Commander in Chief Army Forces Pacific Advance Yokohoma Japan to Commander in Chief Army Forces Pacific Administration, September 14, 1945, Secret

Source: RG 77, Tinian Files, April-December 1945, box 17, Envelope B

A month after the attacks Groves’ deputy, General Farrell, traveled to Japan to see for himself the destruction of Hiroshima and Nagasaki. His vivid account shows that senior military officials in the Manhattan Project were no longer dismissive of reports of radiation poisoning. As Farrell observed in his discussion of Hiroshima, “Summaries of Japanese reports previously sent are essentially correct, as to clinical effects from single gamma radiation dose.” Such findings dismayed Groves, who worried that the bomb would fall into a taboo category like chemical weapons, with all the fear and horror surrounding them. Thus, Groves and others would try to suppress findings about radioactive effects, although that was a losing proposition. [76]

XII. Eisenhower and McCloy’s Views on the Bombings and Atomic Weapons

Document 95 : Entry for 4 October 1945, Robert P. Meiklejohn Diary

In this entry written several months later, Meiklejohn shed light on what much later became an element of the controversy over the Hiroshima-Nagasaki bombings: whether any high level civilian or military officials objected to nuclear use. Meiklejohn recounted Harriman’s visit in early October 1945 to the Frankfurt-area residence of General Dwight Eisenhower, who was finishing up his service as Commanding General, U.S. Army, European Theater. It was Meiklejohn’s birthday and during the dinner party, Eisenhower and McCloy had an interesting discussion of atomic weapons, which included comments alluding to scientists’ statements about what appears to be the H-bomb project (a 20 megaton weapon), recollection of the early fear that an atomic detonation could burn up the atmosphere, and the Navy’s reluctance to use its battleships to test atomic weapons. At the beginning of the discussion, Eisenhower made a significant statement: he “mentioned how he had hoped that the war might have ended without our having to use the atomic bomb.” The general implication was that prior to Hiroshima-Nagasaki, he had wanted to avoid using the bomb.

Some may associate this statement with one that Eisenhower later recalled making to Stimson. In his 1948 memoirs (further amplified in his 1963 memoirs), Eisenhower claimed that he had “expressed the hope [to Stimson] that we would never have to use such a thing against an enemy because I disliked seeing the United States take the lead in introducing into war something as horrible and destructive as this new weapon was described to be.” That language may reflect the underlying thinking behind Eisenhower’s statement during the dinner party, but whether Eisenhower used such language when speaking with Stimson has been a matter of controversy. In later years, those who knew both thought it unlikely that the general would have expressed misgivings about using the bomb to a civilian superior. Eisenhower’s son John cast doubts about the memoir statements, although he attested that when the general first learned about the bomb he was downcast.

Stimson’s diary mentions meetings with Eisenhower twice in the weeks before Hiroshima, but without any mention of a dissenting Eisenhower statement (and Stimson’s diaries are quite detailed on atomic matters). The entry from Meiklejohn’s diary does not prove or disprove Eisenhower’s recollection, but it does confirm that he had doubts which he expressed only a few months after the bombings. Whether Eisenhower expressed such reservations prior to Hiroshima will remain a matter of controversy. [77]

Document 96:  President Harry S. Truman, Handwritten Remarks for Gridiron Dinner, circa 15 December 1945 [78]

Source: Harry S. Truman Library,  President's Secretary's Files,  Speech Files, 1945-1953,  copy on U.S. National Archives Web Site

On 15 December, President Truman spoke about the atomic bombings in his speech at the annual dinner of the Gridiron Club, organized by bureau chiefs and other leading figures of print media organizations. Besides Truman, guests included New York Governor Thomas Dewey (Republican presidential candidate in 1944 and 1948), foreign ambassadors, members of the cabinet and the Supreme Court, the military high command, and various senators and representatives. The U.S. Marine Band provided music for the dinner and for the variety show that was performed by members of the press.  [79]

In accordance with the dinner’s rules that “reporters are never present,” Truman’s remarks were off-the record. The president, however, wrote in long-hand a text that that might approximate what he said that evening. Pages 12 through 15 of those notes refer to the atomic bombing of Japan:

“You know the most terrible decision a man ever had to make was made by me at Potsdam. It had nothing to do with Russia or Britain or Germany. It was a decision to loose the most terrible of all destructive forces for the wholesale slaughter of human beings. The Secretary of War, Mr. Stimson, and I weighed that decision most prayerfully. But the President had to decide. It occurred to me that a quarter of a million of the flower of our young manhood was worth a couple of Japanese cities, and I still think that they were and are. But I couldn’t help but think of the necessity of blotting out women and children and non-combatants. We gave them fair warning and asked them to quit. We picked a couple of cities where war work was the principle industry, and dropped bombs. Russia hurried in and the war ended.”

Truman characterized the Potsdam Declaration as a “fair warning,” but it was an ultimatum. Plainly he was troubled by the devastation and suffering caused by the bombings, but he found it justifiable because it saved the lives of U.S. troops. His estimate of 250,000 U.S. soldiers spared far exceeded that made by General Marshall in June 1945, which was in the range of 31,000 (comparable to the Battle of Luzon) [See Document 26]. By citing an inflated casualty figure, the president was giving a trial run for the rationale that would become central to official and semi-official discourse about the bombings during the decades ahead. [80]  

Despite Truman’s claim that he made “the most terrible” decision at Potsdam, he assigned himself more responsibility than the historical record supports. On the basic decision, he had simply concurred with the judgments of Stimson, Groves, and others that the bomb would be used as soon as it was available for military use. As for targeting, however, he had a more significant role. At Potsdam, Stimson raised his objections to targeting Japan’s cultural capital, Kyoto, and Truman supported the secretary’s efforts to drop that city from the target list [See Documents 47 and 48].  [81]

Where he had taken significant responsibility was by making a decision to stop the atomic bombings just before the Japanese surrender, thereby asserting presidential control over nuclear weapons

The editor thanks Barton J. Bernstein, J. Samuel Walker, Gar Alperovitz, David Holloway, and Alex Wellerstein for their advice and assistance, and Tsuyoshi Hasegawa for kindly providing copies of some of the Japanese sources that were translated for this compilation. Hasegawa’s book,  Racing the Enemy: Stalin, Truman, and the Surrender of Japan  (Cambridge, Harvard University Press, 2005), includes invaluable information on Japanese sources. David Clark, an archivist at the Harry S. Truman Library, and James Cross, Manuscripts Archivist at Clemson University Library’s Special Collections, kindly provided material from their collections. The editor also thanks Kyle Hammond and Gregory Graves for research assistance and Toshihiro Higuchi and Hikaru Tajima (who then were graduate students in history at Georgetown University and the University of Tokyo respectively), for translating documents and answering questions on the Japanese sources. The editor thanks Anna Melyakova (National Security Archive) for translating Russian language material.

Read the documents

I. background on the u.s. atomic project   documents 1a-c: report of the uranium committee.

Document 1A

National Archives, Records of the Office of Scientific Research and Development, Record Group 227 (hereinafter RG 227), Bush-Conant papers microfilm collection, Roll 1, Target 2, Folder 1, "S-1 Historical File, Section A (1940-1941)."

Document 1B

See description of document 1A.

Document 1C

Document 2A

RG 227, Bush-Conant papers microfilm collection, Roll 1, Target 2, Folder 1, "S-1 Historical File, Section II (1941-1942)

Document 2B

Bush-Conant papers, S-1 Historical File, Reports to and Conferences with the President (1942-1944)

See description of document 2A.

National Archives, Record Group 77, Records of the Army Corps of Engineers (hereinafter RG 77), Manhattan Engineering District (MED), Minutes of the Military Policy Meeting (5 May 1943), Correspondence (“Top Secret”) of the Manhattan Engineer District, 1942-1946, microfilm publication M1109 (Washington, D.C.: National Archives and Records Administration, 1980), Roll 3, Target 6, Folder 23, “Military Policy Committee, Minutes of Meetings”

Before the Manhattan Project had produced any weapons, senior U.S. government officials had Japanese targets in mind. Besides discussing programmatic matters (e.g., status of gaseous diffusion plants, heavy water production for reactors, and staffing at Las Alamos), the participants agreed that the first use could be Japanese naval forces concentrated at Truk Harbor, an atoll in the Caroline Islands. If there was a misfire the weapon would be difficult for the Japanese to recover, which would not be the case if Tokyo was targeted. Targeting Germany was rejected because the Germans were considered more likely to “secure knowledge” from a defective weapon than the Japanese. That is, the United States could possibly be in danger if the Nazis acquired more knowledge about how to build a bomb. [9]

RG 77, Correspondence ("Top Secret") of the Manhattan Engineer District, 1942-1946, file 25M

This memorandum from General Groves to General Marshall captured how far the Manhattan Project had come in less than two years since Bush’s December 1942 report to President Roosevelt. Groves did not mention this but around the time he wrote this the Manhattan Project had working at its far-flung installations over 125,000 people ; taking into account high labor turnover some 485,000 people worked on the project (1 out of every 250 people in the country at that time). What these people were laboring to construct, directly or indirectly, were two types of weapons—a gun-type weapon using U-235 and an implosion weapon using plutonium (although the possibility of U-235 was also under consideration). As the scientists had learned, a gun-type weapon based on plutonium was “impossible” because that element had an “unexpected property”: spontaneous neutron emissions would cause the weapon to “fizzle.” [10] For both the gun-type and the implosion weapons, a production schedule had been established and both would be available during 1945. The discussion of weapons effects centered on blast damage models; radiation and other effects were overlooked.

RG 77, Harrison-Bundy Files (H-B Files), folder 69 (copy from microfilm)

Documents 6A-D: President Truman Learns the Secret

Document 6A

G 77, Commanding General’s file no. 24, tab D

Soon after he was sworn in as president following President Roosevelt’s death, Harry Truman learned about the top secret Manhattan Project from briefings by  Secretary of War Stimson and Manhattan Project chief General Groves (who went through the “back door” to escape the watchful press). Stimson, who later wrote up the meeting in his diary, also prepared a discussion paper, which raised broader policy issues associated with the imminent possession of “the most terrible weapon ever known in human history.”

In a background report prepared for the meeting, Groves provided a detailed overview of the bomb project from the raw materials to processing nuclear fuel to assembling the weapons to plans for using them, which were starting to crystallize. With respect to the point about assembling the weapons, Groves and Stimson informed Truman that the first gun-type weapon “should be ready about 1 August 1945” while an implosion weapon would also be available that month. “The target is and was always expected to be Japan.”  

These documents have important implications for the perennial debate over whether Truman “inherited assumptions” from the Roosevelt administration that the bomb would be used when available or that he made  the  decision to do so.  Alperovitz and Sherwin have argued that Truman made “a real decision” to use the bomb on Japan by choosing “between various forms of diplomacy and warfare.” In contrast, Bernstein found that Truman “never questioned [the] assumption” that the bomb would and should be used. Norris also noted that “Truman’s ”decision” amounted to a decision not to override previous plans to use the bomb.” [12]

Document 6B

Henry Stimson Diary, Sterling Library, Yale University (microfilm at Library of Congress)

See description of document 6A.

Document 6C

Record Group 200, Papers of General Leslie R. Groves, Correspondence 1941-1970, box 3, “F”

Document 6D

RG 77, MED Records, Top Secret Documents, File no. 5g

The force of B-29 nuclear delivery vehicles that was being readied for first nuclear use—the Army Air Force’s 509 th Composite Group—required an operational base in the Western Pacific. In late February 1945, months before atomic bombs were ready for use, the high command selected Tinian, an island in the Northern Marianas Islands, for that base.

Library of Congress, Curtis LeMay Papers, Box B-36

As part of the war with Japan, the Army Air Force waged a campaign to destroy major industrial centers with incendiary bombs. This document is General Curtis LeMay’s report on the firebombing of Tokyo--“the most destructive air raid in history”--which burned down over 16 square miles of the city, killed up to 100,000 civilians (the official figure was 83,793), injured more than 40,000, and made over 1 million homeless. [13] According to the “Foreword,” the purpose of the raid, which dropped 1,665 tons of incendiary bombs, was to destroy industrial and strategic targets “ not to bomb indiscriminately civilian populations.” Air Force planners, however, did not distinguish civilian workers from the industrial and strategic structures that they were trying to destroy.

RG 77, MED Records, Top Secret Documents, File no. 5d (copy from microfilm)

On 27 April, military officers and nuclear scientists met to discuss bombing techniques, criteria for target selection, and overall mission requirements. The discussion of “available targets” included Hiroshima, the “largest untouched target not on the 21 st Bomber Command priority list.” But other targets were under consideration, including Yawata (northern Kyushu), Yokohama, and Tokyo (even though it was practically “rubble.”) The problem was that the Air Force had a policy of “laying waste” to Japan’s cities which created tension with the objective of reserving some urban targets for nuclear destruction. [16]

Document 10

RG 77, MED Records, Top Secret Documents, File no. 5g (copy from microfilm)

As director of Los Alamos Laboratory, Oppenheimer’s priority was producing a deliverable bomb, but not so much the effects of the weapon on the people at the target. In keeping with General Groves’ emphasis on compartmentalization, the Manhattan Project experts on the effects of radiation on human biology were at the MetLab and other offices and had no interaction with the production and targeting units. In this short memorandum to Groves’ deputy, General Farrell, Oppenheimer explained the need for precautions because of the radiological dangers of a nuclear detonation. The initial radiation from the detonation would be fatal within a radius of about 6/10ths of a mile and “injurious” within a radius of a mile. The point was to keep the bombing mission crew safe; concern about radiation effects had no impact on targeting decisions. [17]

Document 11

Scientists and officers held further discussion of bombing mission requirements, including height of detonation, weather, radiation effects (Oppenheimer’s memo), plans for possible mission abort, and the various aspects of target selection, including priority cities (“a large urban area of more than three miles diameter”) and psychological dimension. As for target cities, the committee agreed that the following should be exempt from Army Air Force bombing so they would be available for nuclear targeting: Kyoto, Hiroshima, Yokohama, and Kokura Arsenal. Japan’s cultural capital, Kyoto, would not stay on the list. Pressure from Secretary of War Stimson had already taken Kyoto off the list of targets for incendiary bombings and he would successfully object to the atomic bombing of that city. [18]

Document 12

Document 13

Joseph E. Davies Papers, Library of Congress, box 17, 21 May 1945

Document 14

Harrison-Bundy Files relating to the Development of the Atomic Bomb, 1942-1946, microfilm publication M1108 (Washington, D.C.: National Archives and Records Administration, 1980), File 77: "Interim Committee - International Control."

In what Stimson called the “letter of an honest man,” Oswald C. Brewster sent President Truman a profound analysis of the danger and unfeasibility of a U.S. atomic monopoly. [21] An engineer for the Kellex Corporation, which was involved in the gas diffusion project to enrich uranium, Brewster recognized that the objective was fissile material for a weapon. That goal, he feared, raised terrifying prospects with implications for the “inevitable destruction of our present day civilization.” Once the U.S. had used the bomb in combat other great powers would not tolerate a monopoly by any nation and the sole possessor would be “be the most hated and feared nation on earth.” Even the U.S.’s closest allies would want the bomb because “how could they know where our friendship might be five, ten, or twenty years hence.” Nuclear proliferation and arms races would be certain unless the U.S. worked toward international supervision and inspection of nuclear plants.

Document 15

Document 16

At the end of May General Groves forwarded to Army Chief of Staff Marshall a “Plan of Operations” for the atomic bombings. While that plan has not surfaced, apparently its major features were incorporated in this 29 May 1945 message on the “special functions” of the 509th Composite Group sent from Chief of Staff General Lauris Norstad to General Curtis LeMay, chief of the XXI Bomber Command, headquartered in the Marianas Islands. [21A] The Norstad message reviewed the complex requirements for preparing B-29s and their crew for delivering nuclear weapons.  He detailed the mission of the specially modified B-29s that comprised the  509th Composite Group, the “tactical factors” that applied,  training and rehearsal issues, and the functions of “special personnel” and the Operational Studies Group.  The targets listed—Hiroshima, Kyoto, and Niigato—were those that had been discussed at the Target Committee meeting on 28 May, but Kyoto would be dropped when Secretary Stimson objected (although that would remain a contested matter) and Kokura would eventually be substituted.   As part of the Composite Group’s training to drop “special bombs,” it would practice with facsimiles—the conventionally-armed “Pumpkins.” The 509th Composite Group’s cover story for its secret mission was the preparation for the use of “Pumpkins” in battle.

Document 17

Record Group 107, Office of the Secretary of War, Formerly Top Secret Correspondence of Secretary of War Stimson (“Safe File”), July 1940-September 1945, box 12, S-1

Tacitly dissenting from the Targeting Committee’s recommendations, Army Chief of Staff George Marshall argued for initial nuclear use against a clear-cut military target such as a “large naval installation.” If that did not work, manufacturing areas could be targeted, but only after warning their inhabitants. Marshall noted the “opprobrium which might follow from an ill considered employment of such force.” This document has played a role in arguments developed by Barton J. Bernstein that figures such as Marshall and Stimson were “caught between an older morality that opposed the intentional killing of non-combatants and a newer one that stressed virtually total war.” [22]

Document 18

RG 77, MED Records, H-B files, folder no. 100 (copy from microfilm)

With Secretary of War Stimson presiding, members of the committee heard reports on a variety of Manhattan Project issues, including the stages of development of the atomic project,  problems of secrecy, the possibility of informing the Soviet Union, cooperation with “like-minded” powers, the military impact of the bomb on Japan, and the problem of “undesirable scientists.”  In his comments on a detonation over Japanese targets, Oppenheimer mentioned that the “neutron effect would be dangerous to life for a radius of at least two-thirds of a mile,” but did not mention that the radiation could cause prolonged sickness.

Interested in producing the “greatest psychological effect,” the Committee members agreed that the “most desirable target would be a vital war plant employing a large number of workers and closely surrounded by workers’ houses.”  Bernstein argues that this target choice represented an uneasy endorsement of “terror bombing”-the target was not exclusively military or civilian; nevertheless, worker’s housing would include non-combatant men, women, and children. [23] It is possible that Truman was informed of such discussions and their conclusions, although he clung to a belief that the prospective targets were strictly military.

Document 19

Record Group 165, Records of the War Department General and Special Staffs, American-British-Canadian Top Secret Correspondence, Box 504, “ABC 387 Japan (15 Feb. 45)

George A. Lincoln, chief of the Strategy and Policy Group at U.S. Army’s Operations Department, commented on a memorandum by former President Herbert Hoover that Stimson had passed on for analysis. Hoover proposed a compromise solution with Japan that would allow Tokyo to retain part of its empire in East Asia (including Korea and Japan) as a way to head off Soviet influence in the region. While Lincoln believed that the proposed peace teams were militarily acceptable he doubted that they were workable or that they could check Soviet “expansion” which he saw as an inescapable result of World War II. As to how the war with Japan would end, he saw it as “unpredictable,” but speculated that “it will take Russian entry into the war, combined with a landing, or imminent threat of a landing, on Japan proper by us, to convince them of the hopelessness of their situation.” Lincoln derided Hoover’s casualty estimate of 500,000. J. Samuel Walker has cited this document to make the point that “contrary to revisionist assertions, American policymakers in the summer of 1945 were far from certain that the Soviet invasion of Manchuria would be enough in itself to force a Japanese surrender.” [24]

Document 20

Document 21

Henry Stimson Papers, Sterling Library, Yale University (microfilm at Library of Congress)

Stimson and Truman began this meeting by discussing how they should handle a conflict with French President DeGaulle over the movement by French forces into Italian territory. (Truman finally cut off military aid to France to compel the French to pull back). [25] As evident from the discussion, Stimson strongly disliked de Gaulle whom he regarded as “psychopathic.” The conversation soon turned to the atomic bomb, with some discussion about plans to inform the Soviets but only after a successful test. Both agreed that the possibility of a nuclear “partnership” with Moscow would depend on “quid pro quos”: “the settlement of the Polish, Rumanian, Yugoslavian, and Manchurian problems.”

At the end, Stimson shared his doubts about targeting cities and killing civilians through area bombing because of its impact on the U.S.’s reputation as well as on the problem of finding targets for the atomic bomb. Barton Bernstein has also pointed to this as additional evidence of the influence on Stimson of an “an older morality.” While concerned about the U.S.’s reputation, Stimson did not want the Air Force to bomb Japanese cities so thoroughly that the “new weapon would not have a fair background to show its strength,” a comment that made Truman laugh. The discussion of “area bombing” may have reminded him that Japanese civilians remained at risk from U.S. bombing operations.

Document 22

RG 77, MED Records, H-B files, folder no. 76 (copy from microfilm)

Physicists Leo Szilard and James Franck, a Nobel Prize winner, were on the staff of the “Metallurgical Laboratory” at the University of Chicago, a cover for the Manhattan Project program to produce fuel for the bomb. The outspoken Szilard was not involved in operational work on the bomb and General Groves kept him under surveillance but Met Lab director Arthur Compton found Szilard useful to have around. Concerned with the long-run implications of the bomb, Franck chaired a committee, in which Szilard and Eugene Rabinowitch were major contributors, that produced a report rejecting a surprise attack on Japan and recommended instead a demonstration of the bomb on the “desert or a barren island.” Arguing that a nuclear arms race “will be on in earnest not later than the morning after our first demonstration of the existence of nuclear weapons,” the committee saw international control as the alternative. That possibility would be difficult if the United States made first military use of the weapon. Compton raised doubts about the recommendations but urged Stimson to study the report. Martin Sherwin has argued that the Franck committee shared an important assumption with Truman et al.--that an “atomic attack against Japan would `shock’ the Russians”--but drew entirely different conclusions about the import of such a shock. [26]

Document 23

Record Group 107, Office of the Secretary of War, Formerly Top Secret Correspondence of Secretary of War Stimson (“Safe File”), July 1940-September 1945, box 8, Japan (After December 7/41)

Document 24

Document 25

Document 26

Record Group 218, Records of the Joint Chiefs of Staff, Central Decimal Files, 1942-1945, box 198 334 JCS (2-2-45) Mtg 186th-194th

The record of this meeting has figured in the complex debate over the estimates of casualties stemming from a possible invasion of Japan. While post-war justifications for the bomb suggested that an invasion of Japan could have produced very high levels of casualties (dead, wounded, or missing), from hundreds of thousands to a million, historians have vigorously debated the extent to which the estimates were inflated. [29]

Document 27

Document 28

RG 77, MED, H-B files, folder no. 77 (copy from microfilm)

Document 29

Document 30

RG 107, Office of Assistant Secretary of War Formerly Classified Correspondence of John J. McCloy, 1941-1945, box 38, ASW 387 Japan

Document 31

Document 32

Document 33

Naval Aide to the President Files, box 4, Berlin Conference File, Volume XI - Miscellaneous papers: Japan, Harry S. Truman Presidential Library

On 2 July Stimson presented to President Truman a proposal that he had worked up with colleagues in the War Department, including McCloy, Marshall, and Grew. The proposal has been characterized as “the most comprehensive attempt by any American policymaker to leverage diplomacy” in order to shorten the Pacific War. Stimson had in mind a “carefully timed warning” delivered before the invasion of Japan. Some of the key elements of Stimson’s argument were his assumption that “Japan is susceptible to reason” and that Japanese might be even more inclined to surrender if “we do not exclude a constitutional monarchy under her present dynasty.” The possibility of a Soviet attack would be part of the “threat.” As part of the threat message, Stimson alluded to the “inevitability and completeness of the destruction” which Japan could suffer, but he did not make it clear whether unconditional surrender terms should be clarified before using the atomic bomb. Truman read Stimson’s proposal, which he said was “powerful,” but made no commitments to the details, e.g., the position of the emperor. [32]

Document 34

Record Group 353, Records of Interdepartmental and Intradepartmental Committees, Secretary’s Staff Meetings Minutes, 1944-1947 (copy from microfilm)

Document 35

RG 218, Central Decimal Files, 1943-1945, CCS 381 (6-4-45), Sec. 2 Pt. 5

Document 36

Record Group 59, Decimal Files 1945-1949, 740.0011 PW (PE)/7-1645

Document 37

Henry L. Stimson Papers (MS 465), Sterling Library, Yale University (reel 113) (microfilm at Library of Congress)

Still interested in trying to find ways to “warn Japan into surrender,” this represents an attempt by Stimson before the Potsdam conference, to persuade Truman and Byrnes to agree to issue warnings to Japan prior to the use of the bomb. The warning would draw on the draft State-War proclamation to Japan; presumably, the one criticized by Hull (above) which included language about the emperor. Presumably the clarified warning would be issued prior to the use of the bomb; if the Japanese persisted in fighting then “the full force of our new weapons should be brought to bear” and a “heavier” warning would be issued backed by the “actual entrance of the Russians in the war.” Possibly, as Malloy has argued, Stimson was motivated by concerns about using the bomb against civilians and cities, but his latest proposal would meet resistance at Potsdam from Byrnes and other. [34]

Document 38

IV. The Japanese Search for Soviet Mediation   Documents 39A-B: Magic

Document 39A

National Security Agency Mandatory declassification review release.

Beginning in September 1940, U.S. military intelligence began to decrypt routinely, under the “Purple” code-name, the intercepted cable traffic of the Japanese Foreign Ministry. Collectively the decoded messages were known as “Magic.” How this came about is explained in an internal history of pre-war and World War II Army and Navy code-breaking activities prepared by William F. Friedman , a central figure in the development of U.S. government cryptology during the 20 th century. The National Security Agency kept the ‘Magic” diplomatic and military summaries classified for many years and did not release the entire series for 1942 through August 1945 until the early 1990s. [36]

Document 39B

Record Group 457, Records of the National Security Agency/Central Security Service, “Magic” Diplomatic Summaries 1942-1945, box 18.

Document 40

RG 165, Army Operations OPD Executive File #17, Item 13 (copy courtesy of J. Samuel Walker)

Document 41

Record Group 457, Records of the National Security Agency/Central Security Service, “Magic” Diplomatic Summaries 1942-1945, box 18

Document 42

Document 43

Takashi Itoh, ed., Sokichi Takagi: Nikki to Joho [Sokichi Takagi: Diary and Documents] (Tokyo, Japan: Misuzu-Shobo, 2000), 916-917 [Translation by Hikaru Tajima]

Document 44

L.D. Riabev, ed., Atomnyi Proekt SSSR (Moscow: izd MFTI, 2002), Volume 1, Part 2, 335-336

This 10 July 1945 letter from NKVD director V. N. Merkulov to Beria is an example of Soviet efforts to collect inside information on the Manhattan Project, although not all the detail was accurate. Merkulov reported that the United States had scheduled the test of a nuclear device for that same day, although the actual test took place 6 days later. According to Merkulov, two fissile materials were being produced: element-49 (plutonium), and U-235; the test device was fueled by plutonium. The Soviet source reported that the weight of the device was 3 tons (which was in the ball park) and forecast an explosive yield of 5 kilotons. That figure was based on underestimates by Manhattan Project scientists: the actual yield of the test device was 20 kilotons.

Document 45

RG 77, MED Records, Top Secret Documents, File 5e (copy from microfilm)

An elated message from Harrison to Stimson reported the success of the Trinity Test of a plutonium implosion weapon. The light from the explosion could been seen “from here [Washington, D.C.] to “high hold” [Stimson’s estate on Long Island—250 miles away]” and it was so loud that Harrison could have heard the “screams” from Washington, D.C. to “my farm” [in Upperville, VA, 50 miles away] [42]

Document 46

RG 77, MED Records, Top Secret Documents, File no. 4 (copy from microfilm)

Document 47

Barton J. Bernstein, “Truman at Potsdam: His Secret Diary,” Foreign Service Journal, July/August 1980, excerpts, used with author’s permission. [44]

Some years after Truman’s death, a hand-written diary that he kept during the Potsdam conference surfaced in his personal papers. For convenience, Barton Bernstein’s rendition is provided here but linked here are the scanned versions of Truman’s handwriting on the National Archives’ website (for 15-30 July).

Document 48

An important question that Stimson discussed with Marshall, at Truman’s request, was whether Soviet entry into the war remained necessary to secure Tokyo’s surrender. Marshall was not sure whether that was so although Stimson privately believed that the atomic bomb would provide enough to force surrender (see entry for July 23). This entry has been cited by all sides of the controversy over whether Truman was trying to keep the Soviets out of the war. [46] During the meeting on August 24, discussed above, Stimson gave his reasons for taking Kyoto off the atomic target list: destroying that city would have caused such “bitterness” that it could have become impossible “to reconcile the Japanese to us in that area rather than to the Russians.” Stimson vainly tried to preserve language in the Potsdam Declaration designed to assure the Japanese about “the continuance of their dynasty” but received Truman’s assurance that such a consideration could be conveyed later through diplomatic channels (see entry for July 24). Hasegawa argues that Truman realized that the Japanese would refuse a demand for unconditional surrender without a proviso on a constitutional monarchy and that “he needed Japan’s refusal to justify the use of the atomic bomb.” [47]

Document 49

Clemson University Libraries, Special Collections, Clemson, SC; Mss 243, Walter J. Brown Papers, box 10, folder 12, Byrnes, James F.: Potsdam, Minutes, July-August 1945

The degree to which the typed-up version reflects the original is worth investigating. In any event, historians have used information from the diary to support various interpretations. For example, Bernstein cites the entries for 20 and 24 July to argue that “American leaders did not view Soviet entry as a substitute for the bomb” but that the latter “would be so powerful, and the Soviet presence in Manchuria so militarily significant, that there was no need for actual Soviet intervention in the war.” For Brown's diary entry of 3 August 9 1945 historians have developed conflicting interpretations (See discussion of document 57). [48]

Document 50

Document 51

Naval Historical Center, Operational Archives, James Forrestal Diaries

Secretary of the Navy James Forrestal was a regular recipient of “Magic” intercept reports; this substantial entry reviews the dramatic Sato-Togo exchanges covered in the 22 July “Magic” summary (although Forrestal misdated Sato’s cable as “first of July” instead of the 21 st ). In contrast to Alperovitz’s argument that Forrestal tried to modify the terms of unconditional surrender to give the Japanese an out, Frank sees Forrestal’s account of the Sato-Togo exchange as additional evidence that senior U.S. officials understood that Tokyo was not on the “cusp of surrender.” [49]

Document 52

Joseph E. Davies Papers, Library of Congress, Manuscripts Division, box 19, 29 July 1945

VII. Debates among the Japanese – Late July/Early August 1945

Document 53

In the Potsdam Declaration the governments of China, Great Britain, and the United States) demanded the “unconditional surrender of all Japanese armed forces. “The alternative is prompt and utter destruction.” The next day, in response to questions from journalists about the government’s reaction to the ultimatum, Prime Minister Suzuki apparently said that “We can only ignore [ mokusatsu ] it. We will do our utmost to complete the war to the bitter end.” That, Bix argues, represents a “missed opportunity” to end the war and spare the Japanese from continued U.S. aerial attacks. [51] Togo’s private position was more nuanced than Suzuki’s; he told Sato that “we are adopting a policy of careful study.” That Stalin had not signed the declaration (Truman and Churchill did not ask him to) led to questions about the Soviet attitude. Togo asked Sato to try to meet with Soviet Foreign Minister Molotov as soon as possible to “sound out the Russian attitude” on the declaration as well as Japan’s end-the-war initiative. Sato cabled Togo earlier that he saw no point in approaching the Soviets on ending the war until Tokyo had “concrete proposals.” “Any aid from the Soviets has now become extremely doubtful.”

Document 54

Document 55

Document 56

Document 57

Document 58

RG 457, Summaries of Intercepted Japanese Messages (“Magic” Far East Summary, March 20, 1942 – October 2, 1945), box 7, SRS 491-547

Document 59

VIII. The Execution Order   Documents 60A-D: These messages convey the process of creating and transmitting the execution order to bomb Hiroshima. Possibly not wanting to take responsibility for the first use of nuclear weapons, Army Air Force commanders sought formal authorization from Chief of Staff Marshall who was then in Potsdam

Document 60A

RG 77, MED Records, Top Secret Documents, Files no. 5b and 5e (copies from microfilm)

These messages convey the process of creating and transmitting the execution order to bomb Hiroshima.  Possibly not wanting to take responsibility for the first use of nuclear weapons, Army Air Force commanders sought formal authorization from Chief of Staff Marshall who was then in Potsdam. [55] On 22 July Marshall asked Deputy Chief of Staff Thomas Handy to prepare a draft; General Groves wrote one which went to Potsdam for Marshall’s approval. Colonel John Stone, an assistant to commanding General of the Army Air Forces Henry H. “Hap” Arnold, had just returned from Potsdam and updated his boss on the plans as they had developed. On 25 July Marshall informed Handy that Secretary of War Stimson had approved the text; that same day, Handy signed off on a directive which ordered the use of atomic weapons on Japan, with the first weapon assigned to one of four possible targets—Hiroshima, Kokura, Niigata, or Nagasaki. “Additional bombs will be delivery on the [targets] as soon as made ready by the project staff.”

Document 60B

See description of document 60A.

Document 60C

Document 60D

Document 60E

Document 61

RG 77, MED Records, Top Secret Documents, File no. 5

With more information on the Alamogordo test available, Groves provided Marshall with detail on the destructive power of atomic weapons. Barton J. Bernstein has observed that Groves’ recommendation that troops could move into the “immediate explosion area” within a half hour demonstrates the prevalent lack of top-level knowledge of the dangers of nuclear weapons effects. [56] Groves also provided the schedule for the delivery of the weapons: the components of the gun-type bomb to be used on Hiroshima had arrived on Tinian, while the parts of the second weapon to be dropped were leaving San Francisco. By the end of November over ten weapons would be available, presumably in the event the war had continued.

Document 62A

RG 77, Tinian Files, April-December 1945, box 21 (copies courtesy of Barton Bernstein)

Document 62B

See description of document 62A.

Document 62C

Document 63

RG 77, MED Records, Top Secret Documents, File no. 5b (copy from microfilm)

Document 64

Clemson University Libraries, Special Collections, Clemson, SC; Mss 243, Walter J. Brown Papers, box 68, folder 13, “Transcript/Draft B

Returning from the Potsdam Conference, sailing on the U.S.S. Augusta , Truman learned about the atomic bombing of Hiroshima and announced it twice, first to those in the wardroom (socializing/dining area for commissioned officers), and then to the sailors’ mess. Still unaware of radiation effects, Truman emphasized the explosive yield. Later, he met with Secretary of State Byrnes and they discussed the Manhattan Project’s secrecy and the huge expenditures. Truman, who had been chair of the Senate Special Committee to Investigate the National Defense Program, said that “only on the appeal of Secretary of War Stimson did he refrain and let the War Department continue with the experiment unmolested.”

Document 65

A. Zolotarev, ed., Sovetsko-Iaponskaia Voina 1945 Goda: Istoriia Voenno-Politicheskogo Protivoborstva Dvukh Derzhav v 30–40e Gody (Moscow: Terra, 1997 and 2000), Vol. 7 (1), 340-341.

Document 66

Library of Congress Manuscript Division, Papers of W. Averell Harriman, box 181, Chron File Aug 5-9, 1945.

Documents 67A-B: Early High-level Reactions to the Hiroshima Bombing

Document 67A

Gaimusho (Ministry of Foreign Affairs) ed. Shusen Shiroku (The Historical Records of the End of the War), annotated by Jun Eto, volume 4, 57-60 [Excerpts] [Translation by Toshihiro Higuchi]

Excerpts from the Foreign Ministry's compilation about the end of the war show how news of the bombing reached Tokyo as well as how Foreign Minister's Togo initially reacted to reports about Hiroshima. When he learned of the atomic bombing from the Domei News Agency, Togo believed that it was time to give up and advised the cabinet that the atomic attack provided the occasion for Japan to surrender on the basis of the Potsdam Declaration. Togo could not persuade the cabinet, however, and the Army wanted to delay any decisions until it had learned what had happened to Hiroshima. When the Foreign Minister met with the Emperor, Hirohito agreed with him; he declared that the top priority was an early end to the war, although it would be acceptable to seek better surrender terms--probably U.S. acceptance of a figure-head emperor--if it did not interfere with that goal. In light of those instructions, Togo and Prime Minister Suzuki agreed that the Supreme War Council should meet the next day. [59a]

Document 67B

Takashi Itoh, ed., Sokichi Takagi: Nikki to Joho [Sokichi Takagi: Diary and Documents] (Tokyo, Japan: Misuzu-Shobo, 2000), 923-924 [Translation by Hikaru Tajima]

Document 68

Document 69

Library of Congress Manuscript Division, Papers of W. Averell Harriman, box 181, Chron File Aug 5-9, 1945

Document 70

W.A. Harriman Papers, Library of Congress, box 211, Robert Pickens Meiklejohn World War II Diary At London and Moscow March 10, 1941-February 14, 1946, Volume II (Privately printed, 1980 [Printed from hand-written originals]) (Reproduced with permission)

Document 71

Documents 72A-C: The Attack on Nagasaki

Document 72A

RG 77, Tinian Files, April-December 1945, box 20, Envelope G Tinian Files, Top Secret

Document 72B

See description of document 72A.

Document 72C

Document 73A

Library of Congress, J. Robert Oppenheimer Papers, box 60, Ramsey, Norman

Document 73B

See description of document 73A.

Document 74

Document 75

Zenshiro Hoshina, Daitoa Senso Hishi: Hoshina Zenshiro Kaiso-roku [Secret History of the Greater East Asia War: Memoir of Zenshiro Hoshina] (Tokyo, Japan: Hara-Shobo, 1975), excerpts from Section 5, “The Emperor made go-seidan [= the sacred decision] – the decision to terminate the war,” 139-149 [translation by Hikaru Tajima]

Zenshiro Hoshina, a senior naval official, attended the conference and prepared a detailed account. With Prime Minister Suzuki presiding, each of the ministers had a chance to state their views directly to Hirohito. While Army Minister Anami tacitly threatened a coup (“civil war”), the emperor accepted the majority view that the reply to the Potsdam declaration should include only one condition not the four urged by “Big Six.” Nevertheless, the condition that Hirohito accepted was not the one that foreign minister Togo had brought to the conference. What was at stake was the definition of the kokutai (national policy). Togo’s proposal would have been generally consistent with a constitutional monarchy because it defined the kokutai narrowly as the emperor and the imperial household. What Hirohito accepted, however, was a proposal by the extreme nationalist Kiichiro Hiranuma which drew upon prevailing understandings of the kokutai : the “mythical notion” that the emperor was a living god. “This was the affirmation of the emperor’s theocratic powers, unencumbered by any law, based on Shinto gods in antiquity, and totally incompatible with a constitutional monarchy.” Thus, the Japanese response to the Potsdam declaration opposed “any demand which prejudices the prerogatives of his Majesty as a sovereign ruler.” This proved to be unacceptable to the Truman administration. [63]

Document 76

Document 77A

The first Japanese surrender offer was intercepted shortly before Tokyo broadcast it. This issue of the diplomatic summary also includes Togo’s account of his notification of the Soviet declaration of war, reports of Soviet military operations in the Far East, and intercepts of French diplomatic traffic.

Document 77B

A full translation of the surrender offer was circulated separately. The translations differ but they convey the sticking point that prevented U.S. acceptance: Tokyo’s condition that the allies not make any “demand which prejudices the prerogatives of His Majesty as a sovereign ruler.”

Document 78

Papers of Henry A. Wallace, Special Collections Department, University of Iowa Libraries, Iowa City, Iowa (copy courtesy of Special Collections Department)

Note: The second page of the diary entry includes a newspaper clipping of the Associated Press’s transmission of the Byrnes note. Unfortunately, AP would not authorize the Archive to reproduce this item without payment. Therefore, we are publishing an excised version of the entry, with a link to the Byrnes note .

Document 79

Document 80

Stimson’s account of the events of 10 August focused on the debate over the reply to the Japanese note, especially the question of the Emperor’s status. The U.S. reply , drafted during the course of the day, did not explicitly reject the note but suggested that any notion about the “prerogatives” of the Emperor would be superceded by the concept that all Japanese would be “Subject to the Supreme Commander of the Allied Powers.” The language was ambiguous enough to enable Japanese readers, upon Hirohito’s urging, to believe that they could decide for themselves the Emperor’s future role. Stimson accepted the language believing that a speedy reply to the Japanese would allow the United States to “get the homeland into our hands before the Russians could put in any substantial claim to occupy and help rule it.” If the note had included specific provision for a constitutional monarchy, Hasegawa argues, it would have “taken the wind out of the sails” of the military faction and Japan might have surrendered several days earlier, on August 11 or 12 instead of August 14. [65]

Document 81

Clemson University Libraries, Special Collections, Clemson, SC; Mss 243, Walter Brown Papers, box 68, folder 13, “Transcript/Draft B

Brown recounted Byrnes’ debriefing of the 10 August White House meeting on the Japanese peace offer, an account which differed somewhat from that in the Stimson diary. According to what Byrnes told Brown, Truman, Stimson, and Leahy favored accepting the Japanese note, but Byrnes objected that the United States should “go [no] further than we were willing to go at Potsdam.” Stimson’s account of the meeting noted Byrnes’ concerns (“troubled and anxious”) about the Japanese note and implied that he (Stimson) favored accepting it, but did not picture the debate as starkly as Browns's did.

Document 82

George C. Marshall Papers, George C. Marshall Library, Lexington, VA (copy courtesy of Barton J. Bernstein)

Groves informed General Marshall that he was making plans for the use of a third atomic weapon sometime after 17 August, depending on the weather. With Truman having ordered a halt to the atomic bombings [See document 78], Marshall wrote on Grove's memo that the bomb was “not to be released over Japan without express authority from the President.”

Document 83

Library of Congress Manuscript Division, Papers of W. Averell Harriman, box 181, Chron File Aug 10-12, 1945

Document 84

Takashi Itoh, ed., Sokichi Takagi: Nikki to Joho [Sokichi Takagi: Diary and Documents] (Tokyo, Japan: Misuzu-Shobo, 2000), 926-927 [Translation by Hikaru Tajima]

Document 85

National Archives, RG 165, Army Operations OPD, Executive Files 1940-1945, box 12, Exec #2

Document 86

Gaimusho [Ministry of Foreign Affairs], ed., Shusen Shiroku [Historical Record of the End of the War] (Tokyo: Hokuyosha, 1977-1978), vol. 5, 27-35 [Translated by Toshihiro Higuchi]

The Byrnes Note did not break the stalemate at the cabinet level. An account of the cabinet debates on August 13 prepared by Information Minister Toshiro Shimamura showed the same divisions as before; Anami and a few other ministers continued to argue that the Allies threatened the kokutai and that setting the four conditions (no occupation, etc.) did not mean that the war would continue. Nevertheless, Anami argued, “We are still left with some power to fight.” Suzuki, who was working quietly with the peace party, declared that the Allied terms were acceptable because they gave a “dim hope in the dark” of preserving the emperor. At the end of the meeting, he announced that he would report to Hirohito and ask him to make another “Sacred Judgment”. Meanwhile, junior Army officers plotted a coup to thwart the plans for surrender. [68]

Document 87

George C. Marshall Library, Lexington, VA, George C. Marshall Papers (copy courtesy of Barton J. Bernstein)

Document 88

Document 89

Hiroshi [Kaian) Shimomura, Shusenki [Account of the End of the War] (Tokyo, Kamakura Bunko, [1948], 148-152 [Translated by Toshihiro Higuchi]

Frightened by the rapid movement of Soviet forces into Manchuria and worried that the army might launch a coup, the peace party set in motion a plan to persuade Hirohito to meet with the cabinet and the “Big Six” to resolve the stalemate over the response to the Allies. Japan was already a day late in responding to the Byrnes Note and Hirohito agreed to move quickly. At 10:50 a.m., he met with the leadership at the bomb shelter in his palace. This account, prepared by Director of Information Shimomura, conveys the drama of the occasion (as well as his interest in shifting the blame for the debacle to the Army). After Suzuki gave the war party--Umeda, Toyoda, and Anami--an opportunity to present their arguments against accepting the Byrnes Note, he asked the emperor to speak.

Hirohito asked the leadership to accept the Note, which he believed was “well intentioned” on the matter of the “national polity” (by leaving open a possible role for the Emperor). Arguing that continuing the war would reduce the nation “to ashes,” his words about “bearing the unbearable” and sadness over wartime losses and suffering prefigured the language that Hirohito would use in his public announcement the next day. According to Bix, “Hirohito's language helped to transform him from a war to a peace leader, from a cold, aloof monarch to a human being who cared for his people” but “what chiefly motivated him … was his desire to save a politically empowered throne with himself on it.” [70]

Hirohito said that he would make a recording of the surrender announcement so that the nation could hear it. That evening army officers tried to seize the palace and find Hirohito’s recording, but the coup failed. Early the next day, General Anami committed suicide. On the morning of August 15, Hirohito broadcast the message to the nation (although he never used the word “surrender”). A few weeks later, on September 2, 1945 Japanese representatives signed surrender documents on the USS Missouri , in Tokyo harbor. [71]

Document 90

Document 91

The British National Archives, Records of the Foreign and Commonwealth Office, FO 800/461

With the Japanese surrender announcement not yet in, President Truman believed that another atomic bombing might become necessary. After a White House meeting on 14 August, British Minister John Balfour reported that Truman had “remarked sadly that he now had no alternative but to order an atomic bomb to be dropped on Tokyo.” This was likely emotional thinking spurred by anxiety and uncertainty. Truman was apparently not considering the fact that Tokyo was already devastated by fire bombing and that an atomic bombing would have killed the Emperor, which would have greatly complicated the process of surrender. Moreover, he may not have known that the third bomb was still in the United States and would not be available for use for nearly another week. [73] As it turned out, a few hours later, at 4:05 p.m., the White House received the Japanese surrender announcement.

Document 92

Department of Energy Open-Net

Two scientists at Oak Ridge’s Health Division, Henshaw and Coveyou, saw a United Press report in the Knoxville News Sentinel about radiation sickness caused by the bombings. Victims who looked healthy weakened, “for unknown reasons” and many died. Lacking direct knowledge of conditions in Hiroshima and Nagasaki, Henshaw and Coveyou had their own data on the biological effects of radiation and could make educated guesses. After reviewing the impact of various atomic bomb effects--blast, heat, flash radiation (prompt effects from gamma and neutron radiation), and radiation from radioactive substances--they concluded that “it seems highly plausible that a great many persons were subjected to lethal and sub-lethal dosages of radiation in areas where direct blast effects were possibly non-lethal.” It was “probable,” therefore, that radiation “would produce increments to the death rate and “even more probable” that a “great number of cases of sub-lethal exposures to radiation have been suffered.” [74]

Document 93

RG 77, MED Records, Top Secret Documents, File no. 5b

Document 94A

RG 77, Tinian Files, April-December 1945, box 17, Envelope B

See description of document 94B

Document 94B

XII. Eisenhower and McCloy’s Views on the Bombings and Atomic Weapons

Document 95

Document 96

Harry S. Truman Library, President's Secretary's Files, Speech Files, 1945-1953, copy on U.S. National Archives Web Site

On 15 December, President Truman spoke about the atomic bombings in his speech at the annual dinner of the Gridiron Club, organized by bureau chiefs and other leading figures of print media organizations. Besides Truman, guests included New York Governor Thomas Dewey (Republican presidential candidate in 1944 and 1948), foreign ambassadors, members of the cabinet and the Supreme Court, the military high command, and various senators and representatives. The U.S. Marine Band provided music for the dinner and for the variety show that was performed by members of the press. [79]

Truman characterized the Potsdam Declaration as a “fair warning,” but it was an ultimatum. Plainly he was troubled by the devastation and suffering caused by the bombings, but he found it justifiable because it saved the lives of U.S. troops. His estimate of 250,000 U.S. soldiers spared far exceeded that made by General Marshall in June 1945, which was in the range of 31,000 (comparable to the Battle of Luzon) [See Document 26]. By citing an inflated casualty figure, the president was giving a trial run for the rationale that would become central to official and semi-official discourse about the bombings during the decades ahead. [80]

Despite Truman’s claim that he made “the most terrible” decision at Potsdam, he assigned himself more responsibility than the historical record supports. On the basic decision, he had simply concurred with the judgments of Stimson, Groves, and others that the bomb would be used as soon as it was available for military use. As for targeting, however, he had a more significant role. At Potsdam, Stimson raised his objections to targeting Japan’s cultural capital, Kyoto, and Truman supported the secretary’s efforts to drop that city from the target list [See Documents 47 and 48]. [81]

[1] . The World Wide Web includes significant documentary resources on these events. The Truman Library has published a helpful collection of archival documents , some of which are included in the present collection. A collection of transcribed documents is Gene Dannen’s “ Atomic Bomb: Decision .” For a print collection of documents, see Dennis Merrill ed.,  Documentary History of the Truman Presidency: Volume I: The Decision to Drop the Atomic Bomb on Japan  (University Publications of America, 1995). A more recent collection of documents, along with a bibliography, narrative, and chronology, is Michael Kort’s  The Columbia Guide to Hiroshima and the Bomb  (New York: Columbia University Press, 2007). An important  on-line collection focuses on the air-raids of Japanese cities and bases, providing valuable context for the atomic attacks.

[2] . For the early criticisms and their impact on Stimson and other former officials, see Barton J. Bernstein, “Seizing the Contested Terrain of Early Nuclear History: Stimson, Conant, and Their Allies Explain the Decision to Use the Atomic Bomb,”  Diplomatic History  17 (1993): 35-72, and James Hershberg,  James B. Conant: Harvard to Hiroshima and the Making of the Nuclear Age  (Stanford, Stanford University Press, 1995), 291-301.

For Stimson’s article, see “The Decision to Use the Atomic Bomb,”  Harper’s  194 (February 1947): 97-107. Social critic Dwight MacDonald published trenchant criticisms immediately after Hiroshima-Nagasaki; see  Politics Past: Essays in Political Criticism  (New York: Viking, 1972), 169-180.

[3] . The proposed script for the Smithsonian exhibition can be seen at Philipe Nobile,

Judgment at the Smithsonian  (New York: Matthews and Company, 1995), pp. 1-127. For reviews of the controversy, see Barton J. Bernstein, “The Struggle Over History: Defining the Hiroshima Narrative,” ibid., 128-256, and Charles T. O’Reilly and William A. Rooney,  The Enola Gay and The Smithsonian  (Jefferson, NC: McFarland and Company, 2005).

[4] . For the extensive literature, see the references in J. Samuel Walker , Prompt and Utter Destruction: Truman and the Use of Atomic Bombs against Japan,  Third Edition (Chapel Hill: University of North Carolina Press, 2016) at 131-136, as well as Walker’s, “Recent Literature on Truman’s Atomic Bomb Decision: A Search for Middle Ground,”  Diplomatic History  29 (April 2005): 311-334. For more recent contributions, see Sean Malloy,  Atomic Tragedy: Henry L. Stimson and the Decision to Use the Bomb Against Japan  (Ithaca: Cornell University Press, 2008), Andrew Rotter,  Hiroshima: The World's Bomb  (New York: Oxford, 2008), Campbell Craig and Sergey Radchenko,  The Atomic Bomb and the Origins of the Cold War  (New Haven, Yale University Press, 2008), Wilson D. Miscamble,  The Most Controversial Decision: Truman, the Atomic Bombs, and the Defeat of Japan  (New York: Cambridge University Press, 2011). Also important to take into account is John Dower’s extensive discussion of Hiroshima/Nagasaki in context of the U.S. fire-bombings of Japanese cities in  Cultures of War: Pearl Harbor/Hiroshima/9-11/Iraq  (New York, W. Norton, 2010), 163-285.

[5] . The editor particularly benefited from the source material cited in the following works: Robert S. Norris,  Racing for the Bomb: General Leslie S. Groves, The Manhattan Project’s Indispensable Man  (South Royalton, VT: Steerforth Press, 2002); Gar Alperovitz,  The Decision to Use the Bomb and the Architecture of an American Myth  (New York: Alfred E. Knopf, 1995); Richard B. Frank , Downfall: The End of the Imperial Japanese Empire  (New York: Random House, 1999), Martin Sherwin,  A World Destroyed: Hiroshima and the Origins of the Arm Race  (New York, Vintage Books, 1987), and as already mentioned, Hasegawa’s  Racing the Enemy: Stalin, Truman, and the Surrender of Japan  (Cambridge, Harvard University Press, 2005 ).  Barton J. Bernstein’s numerous articles in scholarly publications (many of them are listed in Walker’s assessment of the literature) constitute an invaluable guide to primary sources. An article that Bernstein published in 1995, “The Atomic Bombings Reconsidered,”  Foreign Affairs  74 (1995), 135-152, nicely summarizes his thinking on the key issues.   Noteworthy publications since 2015 include Michael D. Gordin and G. John Ikenberry, eds., The Age of Hiroshim a (Princeton: Princeton University Press, 2019); Sheldon Garon, “On the Transnational Destruction of Cities: What Japan and the United States Learned from the Bombing of Britain and Germany in the Second World War,” Past and Present 247 (2020): 235-271; Katherine E. McKinney, Scott Sagan, and Allen S. Weiner, “Why the Atomic Bombing of Hiroshima Would Be Illegal Today,” The Bulletin of the Atomic Scientist s 76 (2020); Gregg Mitchell, The Beginning or the End: How Hollywood and America Learned  to Stop Worrying and Love the Bomb (New York: The New Press, 2020); Steve Olson, The Apocalypse Factory: Plutonium and the Making of the Atomic Age (New York: W.W. Norton, 2020); Neil J. Sullivan, The Prometheus Bomb: The Manhattan Project and Government in the Dark  (Lincoln, NE: University of Nebraska Press/Potomac Books, 2016); Alex Wellerstein; Restricted Data: The History of Nuclear Secrecy in the United States,  (Chicago: University of Chicago Press, forthcoming, 2020), a memoir by a Hiroshima survivor, Taniguchi Sumitero, The Atomic  Bomb on My Back: A Life Story of Survival and Activism (Montpelier, VT: Rootstock Publishing, 2020), and a collection of interviews, Cynthia C. Kelly, ed., The Manhattan Project: The Birth of the Atomic Bomb in the Words of Its Creators, Eyewitnesses, and Historians (Black Dog & Leventhal, 2020).

[6] . Malloy (2008), 49-50. For more on the Uranium Committee, the decision to establish the S-1 Committee, and the overall context, see James G. Hershberg , James B. Conant: Harvard to Hiroshima and the Making of the Nuclear Age  (Stanford, Stanford University Press, 1995), 140-154.

[7] . Sean Malloy, “`A Very Pleasant Way to Die’: Radiation Effects and the Decision to Use the Atomic Bomb against Japan,”  Diplomatic History  36 (2012), especially 523. For an important study of how contemporary officials and scientists looked at the atomic bomb prior to first use in Japan, see Michael D. Gordin,  Five Days in August: How World War II Became a Nuclear War  (Princeton: Princeton University Press, 2007).

[8] . Norris, 169.

[9] . Malloy (2008), 57-58.

[10] . See also Norris, 362.

[11] . For discussion of the importance of this memorandum, see Sherwin, 126-127, and Hershberg , James B. Conant , 203-207.

[12] . Alperovitz, 662; Bernstein (1995), 139; Norris, 377.

[13] . Quotation and statistics from Thomas R. Searle, “`It Made a Lot of Sense to Kill Skilled Workers’: The Firebombing of Tokyo in March 1945,  The Journal of Military History  55 (2002):103. More statistics and a detailed account of the raid is in Ronald Schaffer,  Wings of Judgment: American Bombing in World War II  (New York: Oxford University Press, 1985), 130-137.

[14] . Searle, “`It Made a Lot of Sense to Kill Skilled Workers,’” 118. For detailed background on the Army Air Force’s incendiary bombing planning, see Schaffer (1985) 107-127. On Stimson, see Schaffer (1985), 179-180 and Malloy (2008), 54. For a useful discussion of the firebombing of Tokyo and the atomic bombings, see Alex Wellerstein, “Tokyo vs. Hiroshima,”  Restricted Data: The Nuclear Secrecy Blog ,  22 September 2014

[15] . See for example, Bernstein (1995), 140-141.

[16] . For useful discussion of this meeting and the other Target Committee meetings, see Norris, 382-386.

[17] . Malloy, “A Very Pleasant Way to Die,” 531-534.

[18] . Schaffer,  Wings of Judgment , 143-146.

[19] . Alperovitz argues that the possibility of atomic diplomacy was central to the thinking of Truman and his advisers, while Bernstein, who argues that Truman’s primary objective was to end the war quickly, suggests that the ability to “cow other nations, notably the Soviet Union” was a “bonus” effect. See Bernstein (1995), 142.

[20] . Alperovitz, 147; Robert James Maddox,  Weapons for Victory: The Hiroshima Decision Fifty Years Later  (Columbia: University of Missouri Press, 1995), 52; Gabiel Kolko,  The Politics of War: The World and United States Foreign Policy, 1943-1945  (New York: Pantheon Books, 1990), 421-422. As Alperovitz notes, the Davies papers include variant diary entries and it is difficult to know which are the most accurate.

[21] . Malloy (2008), 112

[21A] . Vincent Jones, Manhattan: The Army and the Atomic Bomb (Washington, D.C.: U.S. Army Center of Military History, 1985), 529.

[22] . Bernstein (1995), 146. See also Barton J. Bernstein, “Looking Back: Gen. Marshall and the Atomic Bombing of Japanese Cities,” Arms Control Today , November 2015.

[23] . Bernstein (1995), 144. See also Malloy (2008), at 116-117, including the argument that 1) Stimson was deceiving himself by accepting the notion that a “vital war plant …surrounded by workers’ houses” was a legitimate military target, and 2) that Groves was misleading Stimson by withholding the Target Committee’s conclusions that the target would be a city center.

[24] . Walker (2005), 320.

[25] . Frank Costigliola,  France and the United States: The Cold Alliance Since World War II  (New York, Twayne, 1992), 38-39.

[26] . Barton J. Bernstein, Introduction to Helen S. Hawkins et al. editors,  Toward a Livable World: Leo Szilard and the Crusade for Nuclear Arms Control  (Cambridge: MIT Press, 1987), xxx-xxv; Sherwin, 210-215.

[27] . Herbert P. Bix,  Hirohito and the Making of Modern Japan  (New York: HarperCollins Publishers, 2000), 523.

[28] . Walker (2005), 319-320.

[29] . For a review of the debate on casualty estimates, see Walker (2005), 315, 317-318, 321, 323, and 324-325.

[30] . Hasegawa, 105; Alperovitz, 67-72; Forrest Pogue,  George C. Marshall: Statesman, 1945-1959  (New York: Viking, 1987), 18. Pogue only cites the JCS transcript of the meeting; presumably, an interview with a participant was the source of the McCloy quote.

[31] . Alperovitz, 226; Bernstein, “Understanding the Atomic Bomb and the Japanese Surrender,”  Diplomatic History  19 (1995), 237, note 22.

[32] . Malloy (2008), 123-124.

[33] . Alperovitz, 242, 245; Frank, 219.

[34] . Malloy (2008), 125-127.

[35] . Bernstein, introduction,  Toward a Livable World , xxxvii-xxxviii.

[36] . “Magic” summaries for post-August 1945 remain classified at the National Security Agency. Information from the late John Taylor, National Archives. For background on Magic and the “Purple” code, see John Prados,  Combined Fleet Decoded: The Secret History of American Intelligence and the Japanese Navy in World War II (  New York: Random House, 1995), 161-172 and David Kahn,  The Codebreakers: The Story of Secret Writing  (New York: Scribner, 1996), 1-67.

[37] . Alperovitz, 232-238.

[38] . Maddox, 83-84; Hasegawa, 126-128. See also Walker (2005), 316-317.

[39] . Hasegawa, 28, 121-122.

[40] . Peter Grose,  Gentleman Spy: The Life of Allen Dulles  (Boston: Houghton Mifflin, 1994), 170-174, 248-249.

[41] . David Holloway, “Barbarossa and the Bomb: Two Cases of Soviet Intelligence in World War II,” in Jonathan Haslam and Karina Urbach, eds.,  Secret Intelligence in the European States System, 1918-1989  (Stanford: Stanford University Press, 2014), 63-64. For the inception of the Soviet nuclear program and the role of espionage in facilitating it, see Holloway,  Stalin and the Bomb  (New Haven, Yale University Press, 1994).

[42] . For the distances, see Norris, 407.

[43] . For on-line resources on the first atomic test .

[44] . Bernstein’s detailed commentary on Truman’s diary has not been reproduced here except for the opening pages where he provides context and background.

[45] . Frank, 258; Bernstein (1995), 147; Walker (2005), 322. See also Alex Wellerstein’s “ The Kyoto Misconception ”

[46] . Maddox, 102; Alperovitz, 269-270; Hasegawa, 152-153.

[47] . Hasegawa, 292.

[48] . Bernstein, “Understanding the Atomic Bomb and the Japanese Surrender,”  Diplomatic History  19 (1995), 146-147; Alperovitz, 415; Frank, 246.

[49] . Alperovitz, 392; Frank, 148.

[50] . Alperovitz, 281-282. For Davies at Potsdam, see Elizabeth Kimball MacLean,  Joseph E. Davies: Envoy to the Soviets  (Westport, CT: Praeger, 1992), 151-166

[51] . Hasegawa, 168; Bix, 518.

[52] . Bix, 490, 521.

[53] . Alperovitz, 415; Frank, 246.

[54] . Frank, 273-274; Bernstein, “The Alarming Japanese Buildup on Southern Kyushu, Growing U.S. Fears and Counterfactual Analysis: Would the Planned November 1945 Invasion of Southern Kyushu Have Occurred?”  Pacific Historical Review  68 (1999): 561-609.

[55] . Maddox, 105.

[56] . Barton J. Bernstein, "'Reconsidering the 'Atomic General': Leslie R. Groves,"  The Journal of Military History  67 (July 2003): 883-920. See also Malloy, “A Very Pleasant Way to Die,” 539-540.

[57] . For casualty figures and the experience of people on the ground, see Frank, 264-268 and 285-286, among many other sources. Drawing on contemporary documents and journals, Masuji Ibuse’s novel  Black Rain  (Tokyo, Kodansha, 1982) provides an unforgettable account of the bombing of Hiroshima and its aftermath. For early U.S. planning to detonate the weapon at a height designed to maximize destruction from mass fires and other effects, see Alex Wellerstein, “ The Height of the Bomb .”

[58] . Sadao Asada, “The Shock of the Atomic Bomb and Japan’s Decision to Surrender: A Reconsideration,”  Pacific Historical Review  67 (1998): 101-148; Bix, 523; Frank, 348; Hasegawa, 298. Bix appears to have moved toward a position close to Hasegawa’s; see Bix, “Japan's Surrender Decision and the Monarchy: Staying the Course in an Unwinnable War,”  Japan Focus  . For emphasis on the “shock” of the atomic bomb, see also Lawrence Freedman and Saki Dockrill, “Hiroshima: A Strategy of Shock,” in Saki Dockrill, ed.,  From Pearl Harbor to Hiroshima : the Second World War in Asia and the Pacific, 1941-1945  (New York, St. Martin’s Press, 1994), 191-214. For more on the debate over Japan’s surrender, see Hasegawa’s important edited book,  The End of the Pacific War: A Reappraisal  (Stanford: Stanford University Press, 2007), with major contributions by Hasegawa, Holloway, Bernstein, and Hatano.

[59] . Melvyn P. Leffler, “Adherence to Agreements: Yalta and the Experiences of the Early Cold War,”  International Security  11 (1986): 107; Holloway, “Barbarossa and the Bomb,” 65.

[59a] . For more on these developments, see Asada, "The Shock of the Atomic Bomb and Japan's Decision to Surrender: A Reconsideration," 486-488.

[60] . Hasegawa, 191-192.

[61] . Frank, 286-287; Sherwin, 233-237; Bernstein (1995), 150; Maddox, 148.

[62] . The Supreme War Council comprised the prime minister, foreign minister, army and navy ministers, and army and navy chiefs of staff; see Hasegawa, 72 .

[63] . For the maneuverings on August 9 and the role of the  kokutai , see Hasegawa, 3-4, 205-214

[64] . For Truman’s recognition of mass civilian casualties, see also his  letter to Senator Richard Russell, 9 August 1945.

[65] . Hasegawa, 295.

[66] . For “tug of war,” see Hasegawa, 226-227.

[67] . Hasegawa, 228-229, 232.

[68] . Hasegawa, 235-238.

[69] . Barton J. Bernstein, “Eclipsed by Hiroshima and Nagasaki: Early Thinking about Tactical Nuclear Weapons,”  International Security  15 (Spring 1991): 149-173; Marc Gallicchio, “After Nagasaki: General Marshall’s Plans for Tactical Nuclear Weapons in Japan,”  Prologue  23 (Winter 1991): 396-404. Letters from Robert Messer and Gar Alperovitz, with Bernstein’s response, provide insight into some of the interpretative issues. “Correspondence,”  International Security  16 (Winter 1991/1992): 214-221.

[70] . Bix, “Japan's Surrender Decision and the Monarchy: Staying the Course in an Unwinnable War,”  Japan Focus .

[71] . For Hirohito' surrender speech--the actual broadcast and a translation--see  Japan Times , August 2015.

[72] . Cited by Barton J. Bernstein, “Eclipsed by Hiroshima and Nagasaki: Early Thinking About Tactical Nuclear Weapons,”  International Security  15 (1991) at page 167. Thanks to Alex Wellerstein for the suggestion and the archival link.

[73] . For further consideration of Tokyo and more likely targets at the time, see Alex Wellerstein, “Neglected Niigata,”  Restricted Data: The Nuclear Secrecy Blog, 9 October 2015.

[74] . See Malloy, “A Very Pleasant Way to Die,” 541-542.

[75] . For Groves and the problem of radiation sickness, see Norris, 339-441, Bernstein, “Reconsidering the ‘Atomic General’: Leslie R. Groves,”  Journal of Military History  67 (2003), 907-908, and Malloy, “A Very Pleasant Way to Die,” 513-518 and 539-542

[76] . See Janet Farrell Brodie, “Radiation Secrecy and Censorship after Hiroshima and Nagasaki,”  The Journal of Social History  48 (2015): 842-864.

[77] . For Eisenhower’s statements, see  Crusade in Europe  (Garden City: Doubleday, 1948), 443, and  Mandate for Change  (Garden City: Doubleday, 1963), 312-313. Barton J. Bernstein’s 1987 article, “Ike and Hiroshima: Did He Oppose It?”  The Journal of Strategic Studies  10 (1987): 377-389, makes a case against relying on Eisenhower’s memoirs and points to relevant circumstantial evidence. For a slightly different perspective, see Malloy (2007), 138

[78] . Cited in Barton J. Bernstein, “Truman and the A-Bomb: Targeting Noncombatants, Using the Bomb, and His Defending the "Decision,”  The Journal of Military History  62 (1998), at page 559. Thanks to Alex Wellerstein for the suggestion and the archival link.

[79] . “Truman Plays Part of Himself in Skit at Gridiron Dinner,” and “List of Members and Guests at the Gridiron Show,”  The Washington Post , 16 December 1945.

[80] . For varied casualty figures cited by Truman and others after the war, see Walker,  Prompt and Utter Destruction: Truman and the Use of Atomic Bombs Against Japan , 101-102.

[81] . See also ibid., 59.

National Museum of Nuclear Science & History

Debate over the Bomb: An Annotated Bibliography

• Bombings of Hiroshima and Nagasaki

More than seventy years after the end of World War II, the decision to drop the atomic bombs on Hiroshima and Nagasaki  remains controversial . Historians and the public continue to debate if the bombings were justified, the causes of Japan’s surrender, the casualties that would have resulted if the U.S. had invaded Japan, and more. Some historians, often called “traditionalists,” tend to argue that the bombs were necessary in order to save American lives and prevent an invasion of Japan. Other experts, usually called “revisionists,” claim that the bombs were unnecessary and were dropped for other reasons, such as to intimidate the Soviet Union. Many historians have taken positions between these two poles. These books and articles provide a range of perspectives on the atomic bombings. This is not an exhaustive list, but should illustrate some of the different arguments over the decision to use the bombs.

Bibliography on the Debate over the Bomb

• Alperovitz, Gar.  Atomic Diplomacy: Hiroshima and Potsdam . New York: Simon and Schuster, 1965.

——-.  The Decision to Use the Atomic Bomb and the Architecture of an American Myth . New York: Knopf, 1995.

Alperovitz, a prominent revisionist historian, argues that the bombs were unnecessary to force Japan’s surrender. In particular, he posits that the Japanese were already close to surrender and that bombs were primarily intended as a political and diplomatic weapon against the Soviet Union.

• Bernstein, Barton. “Understanding the Atomic Bomb and the Japanese Surrender: Missed Opportunities, Little-Known Near Disasters, and Modern Memory.”  Diplomatic History  19 (Spring 1995): 227-73.

Bernstein challenges the notions that the Japanese were ready to surrender before Hiroshima and that the atomic bombings were primarily intended to intimidate the Soviet Union. He also questions traditionalist claims that the U.S. faced a choice between dropping the bomb and an invasion, and that an invasion would lead to hundreds of thousands of American casualties.

• Bird, Kai, and Lawrence Lifschultz, eds.  Hiroshima’s Shadow: Writings on the Denial of History and the Smithsonian Controversy . Stony Creek, CT: Pamphleteer’s Press, 1998.

This collection of essays and primary source documents, written primarily from a revisionist perspective, provides numerous critiques of the use of the atomic bombs. It includes a foreword by physicist  Joseph Rotblat , who left the Manhattan Project in 1944 on grounds of conscience.

• Bix, Herbert P.  Hirohito and the Making of Modern Japan . New York: Perennial, 2000.

This Pulitzer Prize-winning biography of the Japanese emperor asserts that the Japanese did not decide to surrender until after the bombings and the Soviet invasion of Manchuria. Bix attributes responsibility for the bombings to Hirohito’s “power, authority, and stubborn personality” and President Truman’s “power, determination, and truculence.”

• Craig, Campbell and Radchenko, Sergey.  The Atomic Bomb and the Origins of the Cold War .  New Haven, CT: Yale University Press, 2008.

A provocative study of the entrance of the atomic bomb onto the global stage. It questions the various influences impacting the United States’ decision to drop the bomb, and discusses the Manhattan Project’s role in orchestrating the bipolar conflict of the Cold War.

• Dower, John W.  Cultures of War: Pearl Harbor/Hiroshima/9-11/Iraq . New York: W. W. Norton, 2010.

Dower states that the U.S. used the bombs in order to end the war and save American lives, but asserts that Truman could have waited a few weeks before dropping the bombs to see if the Soviet invasion of Manchuria would compel Japan to surrender. He argues that Truman employed “power politics” in order to keep the Soviet Union in check, and criticizes both Japanese and American leaders for their inability to make peace.

• Feis, Herbert.  Between War and Peace: The Potsdam Conference . Princeton, NJ: Princton University Press, 1960.

Feis presents a blow-by-blow account of the proceedings at the Potsdam Conference that sought to plan the postwar world. He gives particular attention to the discussion of atomic weapons that took place at the conference, noting how it impacted the negotiations of Harry Truman and the American delegation.

• Frank, Richard B.  Downfall: The End of the Imperial Japanese Empire . New York: Penguin Books, 1999.

Frank contends that the Japanese were not close to surrendering before the bombing of Hiroshima. He also concludes that 33,000-39,000 American soldiers would have been killed in an invasion, much lower than the figures usually given by traditionalists.

• Fussell, Paul.  Thank God for the Atom Bomb and Other Essays . New York: Summit Books, 1988.

In the title essay, Fussell, a World War II veteran, vividly recalls the war’s brutality and defends the bombings as a tragic necessity.

• Giangreco, D.M.  Hell to Pay: Operation Downfall and the Invasion of Japan, 1945-1947 . Annapolis, MD: Naval Institute Press, 2009.

Giangreco defends estimates that an invasion of Japan would have cost hundreds of thousands of American lives, and challenges the argument that using the bombs was unjustified.

• Gordin, Michael D.  Five Days in August: How World War II Became a Nuclear War . Princeton, NJ: Princeton University Press, 2007.

Gordin argues that Hiroshima and Nagasaki stemmed from American decisionmakers’ belief that the bombs were merely an especially powerful conventional weapon. He claims U.S. leaders did not “clearly understand the atomic bomb’s revolutionary strategic potential.”

• Ham, Paul.  Hiroshima Nagasaki: The Real Story of the Atomic Bombings and Their Aftermath . Basingstoke, UK: Picador, 2015.

Ham demonstrates that misunderstandings and nationalist fury from both Allied and Axis powers led to the use of the atomic bombs. Ham also gives powerful witness to its destruction through the eyes of eighty survivors, from twelve-year-olds forced to work in war factories to wives and children who faced the holocaust alone.

• Hasegawa, Tsuyoshi.  Racing the Enemy: Stalin, Truman and the Surrender of Japan . Cambridge: Belknap Press of Harvard University Press, 2005.

In this history of the end of World War II from American, Japanese, and Soviet perspectives, Hasegawa determines that the Soviet invasion of Manchuria was the primary factor in compelling the Japanese to surrender.

• Hersey, John.  Hiroshima . New York: Alfred A. Knopf, 1946.

Hersey’s book-length article, which appeared in the  New Yorker  one year after the bombing of Hiroshima, profiles six survivors of the attack. It helped give the American public a new picture of the human impact of the bomb and brought about a groundswell of negative opinion against nuclear weapons.

• Lifton, Robert Jay, and Greg Mitchell.  Hiroshima in America: A Half Century of Denial . New York: Avon Books, 1995.

Written from a revisionist perspective, this book assesses President Truman’s motivations for authorizing the atomic bombings and traces the effects of the bombings on American society.

• Maddox, Robert James.  Weapons for Victory: The Hiroshima Decision Fifty Years Later . Columbia, MO: University of Missouri Press, 1995.

This analysis contends that Japan had not decided to surrender before Hiroshima, states that the U.S. did not believe the Soviet invasion would force Japan to surrender, and challenges the idea that American officials greatly exaggerated the costs of a U.S. invasion of mainland Japan.

• Malloy, Sean.  Atomic Tragedy: Henry L. Stimson and the Decision to Use the Bomb Against Japan .  Ithaca, NY: Cornell University Press, 2008. 

Traces the U.S. government’s decision to drop the atomic bombs on Japan, using the life of Secretary of War Henry L. Stimson as a lens. This biography frames the contested decision as a moral question faced by American policy makers. 

• Miscamble, Wilson D.  The Most Controversial Decision: Truman, the Atomic Bombs, and the Defeat of Japan . New York: Cambridge University Press, 2011.

In this short history, Miscamble critiques various revisionist arguments and posits that the bomb was militarily necessary. He also discusses whether the bombings of Hiroshima and Nagasaki were morally justified.

• Newman, Robert P.  Truman and the Hiroshima Cult . East Lansing, MI: Michigan State University Press, 1995.

Newman argues that Truman made a legitimate military decision to bring the war to an end as quickly as possible. He claims the bombings ultimately saved lives and assails what he calls a “cult” of victimhood surrounding the attacks.

• Rotter, Andrew J.  Hiroshima: The World’s Bomb . Oxford: Oxford University Press, 2008.

This international history of the race to develop the bomb asserts that Truman was primarily motivated by a desire to end the war as quickly as possible, with a minimal loss of American lives. Rotter states that the shocks caused by the atomic bombings and the Soviet invasion of Manchuria were both pivotal to Japan’s surrender.

• Stimson, Henry L. “ The Decision to Use the Atomic Bomb .”  Harper’s Magazine  194:1167 (February 1947): 97-107.

Writing a year and a half after Hiroshima and Nagasaki, former Secretary of War Stimson defends the U.S. decision. He documents the refusal of the Japanese to surrender and estimates that an Allied invasion would have resulted in one million American casualties and many more Japanese deaths.

• Walker, J. Samuel.  Prompt and Utter Destruction: Truman and the Use of Atomic Bombs Against Japan . Chapel Hill: University of North Carolina Press, 2004.

In a concise critique of both traditionalist and revisionist interpretations of Truman’s decision, Walker concludes that the primary motivation for the use of the bombs was to end World War II as quickly as possible.

• Zeiler, Thomas W.  Unconditional Defeat: Japan, America, and the End of World War II . Wilmington, DE: Rowman & Littlefield, 2003.

This history chronicles the brutality of the fighting between the U.S. and Japan in the Pacific. Zeiler concludes that the bombings of Hiroshima and Nagasaki were mostly motivated by military, rather than political, reasons.  

If you have suggestions for resources that should be listed here, please  contact us .

Truman announces Japanese surrender.

Hiroshima Atomic Dome Memorial. Photo by Dmitrij Rodionov, Wikimedia Commons.

Nagasaki, October 1945

Paul Tibbets and the Enola Gay. Courtesy of the Joseph Papalia Collection.

Was It Right?

Most of the debate over the atomic bombing of Japan focuses on the unanswerable question of whether it was necessary. But that skirts the question of its morality.  

I imagine that the persistence of that question irritated Harry Truman above all other things. The atomic bombs that destroyed the cities of Hiroshima and Nagasaki fifty years ago were followed in a matter of days by the complete surrender of the Japanese empire and military forces, with only the barest fig leaf of a condition—an American promise not to molest the Emperor. What more could one ask from an act of war? But the two bombs each killed at least 50,000 people and perhaps as many as 100,000. Numerous attempts have been made to estimate the death toll, counting not only those who died on the first day and over the following week or two but also the thousands who died later of cancers thought to have been caused by radiation. The exact number of dead can never be known, because whole families—indeed, whole districts—were wiped out by the bombs; because the war had created a floating population of refugees throughout Japan; because certain categories of victims, such as conscript workers from Korea, were excluded from estimates by Japanese authorities; and because as time went by, it became harder to know which deaths had indeed been caused by the bombs. However many died, the victims were overwhelming civilians, primarily the old, the young, and women; and all the belligerents formally took the position that the killing of civilians violated both the laws of war and common precepts of humanity. Truman shared this reluctance to be thought a killer of civilians. Two weeks before Hiroshima he wrote of the bomb in his diary, “I have told [the Secretary of War] Mr. Stimson to use it so that military objectives and soldiers and sailors are the target and not women and children.” The first reports on August 6, 1945, accordingly described Hiroshima as a Japanese army base.

This fiction could not stand for long. The huge death toll of ordinary Japanese citizens, combined with the horror of so many deaths by fire, eventually cast a moral shadow over the triumph of ending the war with two bombs. The horror soon began to weigh on the conscience of J. Robert Oppenheimer, the scientific director of the secret research project at Los Alamos, New Mexico, that designed and built the first bombs. Oppenheimer not only had threatened his health with three years of unremitting overwork to build the bombs but also had soberly advised Henry Stimson that no conceivable demonstration of the bomb could have the shattering psychological impact of its actual use. Oppenheimer himself gave an Army officer heading for the Hiroshima raid last minute instructions for proper delivery of the bomb.

Don’t let them bomb through clouds or through an overcast. Got to see the target. No radar bombing; it must be dropped visually. ... Of course, they must not drop it in rain or fog. Don't let them detonate it too high. The figure fixed on is just right. Don't let it go up or the target won’t get as much damage.

These detailed instructions were the result of careful committee work by Oppenheimer and his colleagues. Mist or rain would absorb the heat of the bomb blast and thereby limit the conflagration, which experiments with city bombing in both Germany and Japan had shown to be the principal agent of casualties and destruction. Much thought had also been given to finding the right city. It should be in a valley, to contain the blast; it should be relatively undamaged by conventional air raids, so that there would be no doubt of the bomb's destructive power; an educated citizenry was desired, so that it would understand the enormity of what had happened. The military director of the bomb project, General Leslie Groves, thought the ancient Japanese imperial capital of Kyoto would be ideal, but Stimson had spent a second honeymoon in Kyoto, and was afraid that the Japanese would never forgive or forget its wanton destruction; he flatly refused to leave the city on the target list. Hiroshima and Nagasaki were destroyed instead. On the night of August 6 Oppenheimer was thrilled by the bomb's success. He told an auditorium filled with whistling, cheering, foot-stomping scientists and technicians that he was sorry only that the bomb had not been ready in time for use on Germany. The adrenaline of triumph drained away following the destruction of Nagasaki, on August 9. Oppenheimer, soon offered his resignation and by mid-October had severed his official ties. Some months later he told Truman in the White House, “Mr. President, I have blood on my hands.” Truman was disgusted by this cry-baby attitude. “I told him,” Truman said later, “the blood was on my hands—let me worry about that.” Till the end of his life Truman insisted that he had suffered no agonies of regret over his decision to bomb Hiroshima and Nagasaki, and the pungency of his language suggests that he meant what he said. But it is also true that he ordered a halt to the atomic bombing on August 10, four days before the Japanese Emperor surrendered, and the reason, according to a Cabinet member present at the meeting, was that “he didn’t like the idea of killing ... ‘all those kids.’” Was it right? Harry Truman isn’t the only one to have disliked the question. Historians of the war, of the invention of the atomic bomb, and of its use on Japan have almost universally chosen to skirt the question of whether killing civilians can be morally justified. They ask instead, Was it necessary? Those who say it was necessary argue that a conventional invasion of Japan, scheduled to begin on the southernmost island of Kyushu on November 1, 1945, would have cost the lives of large numbers of Americans and Japanese alike. Much ink has been spilled over just how large these numbers would have been. Truman in later life sometimes said that he had used the atomic bomb to save the lives of half a million or even a million American boys who might have died in an island-by-island battle to the bitter end for the conquest of Japan. Where Truman got those numbers is hard to say. In the spring of 1945, when it was clear that the final stage of the war was at hand, Truman received a letter from former President Herbert Hoover urging him to negotiate an end to the war in order to save the “500,000 to 1 million American lives” that might be lost in an invasion. But the commander of the invasion force, General Douglas MacArthur, predicted nothing on that scale. In a paper prepared for a White House strategy meeting held on June 18, a month before the first atomic bomb was tested, MacArthur estimated that he would suffer about 95,000 casualties in the first ninety days—a third of them deaths. The conflict of estimates is best explained by the fact that they were being used at the time as weapons in a larger argument. Admirals William Leahy and Ernest J. King thought that Japan could be forced to surrender by a combination of bombing and naval blockade. Naturally they inflated the number of casualties that their strategy would avoid. MacArthur and other generals, convinced that the war would have to be won on the ground, may have deliberately guessed low to avoid frightening the President. It was not easy to gauge how the battle would go. From any conventional military perspective, by the summer of 1945 Japan had already lost the war. The Japanese navy mainly rested on the bottom of the ocean; supply lines to the millions of Japanese soldiers in China and other occupied territories had been severed; the Japanese air force was helpless to prevent the almost nightly raids by fleets of B-29 bombers, which had been systematically burning Japanese cities since March; and Japanese petroleum stocks were close to gone. The battleship Yamato , dispatched on a desperate mission to Okinawa in April of 1945, set off without fuel enough to return. But despite this hopeless situation the Japanese military was convinced that a “decisive battle” might inflict so many casualties on Americans coming ashore in Kyushu that Truman would back down and grant important concessions to end the fighting. Japan’s hopes were pinned on “special attack forces,” a euphemism for those engaged in suicide missions, such as kamikaze planes loaded with explosives plunging into American ships, as had been happening since 1944. During the spring and summer of 1945 about 8,000 aircraft, along with one-man submarines and “human torpedoes,” had been prepared for suicide missions, and the entire Japanese population had been exhorted to fight, with bamboo spears if necessary, as “One Hundred Million Bullets of Fire.” Military commanders were so strongly persuaded that honor and even victory might yet be achieved by the “homeland decisive battle” that the peace faction in the Japanese cabinet feared an order to surrender would be disobeyed. The real question is not whether an invasion would have been a ghastly human tragedy, to which the answer is surely yes, but whether Hoover, Leahy, King, and others were right when they said that bombing and blockade would end the war. Here the historians are on firm ground. American cryptanalysts had been reading high-level Japanese diplomatic ciphers and knew that the government in Tokyo was eagerly pressing the Russians for help in obtaining a negotiated peace. The sticking point was narrow: the Allies insisted on unconditional surrender; the Japanese peace faction wanted assurances that the imperial dynasty would remain. Truman knew this at the time. What Truman did not know, but what has been well established by historians since, is that the peace faction in the Japanese cabinet feared the utter physical destruction of the Japanese homeland, the forced removal of the imperial dynasty, and an end to the Japanese state. After the war it was also learned that Emperor Hirohito, a shy and unprepossessing man of forty-four whose first love was marine biology, felt pressed to intervene by his horror at the bombing of Japanese cities. The devastation of Tokyo left by a single night of firebomb raids on March 9–10, 1945, in which 100,000 civilians died, had been clearly visible from the palace grounds for months thereafter. It is further known that the intervention of the Emperor at a special meeting, or gozen kaigin , on the night of August 9–10 made it possible for the government to surrender. The Emperor’s presence at a gozen kaigin is intended to encourage participants to put aside all petty considerations, but at such a meeting, according to tradition, the Emperor does not speak or express any opinion whatever. When the cabinet could not agree on whether to surrender or fight on, the Premier, Kantaro Suzuki, broke all precedent and left the military men speechless when he addressed Hirohito, and said, “With the greatest reverence I must now ask the Emperor to express his wishes.” Of course, this had been arranged by the two men beforehand. Hirohito cited the suffering of his people and concluded, “The time has come when we must bear the unbearable.” After five days of further confusion, in which a military coup was barely averted, the Emperor broadcast a similar message to the nation at large in which he noted that “the enemy has begun to employ a new and most cruel bomb. ... “ Are those historians right who say that the Emperor would have submitted if the atomic bomb had merely been demonstrated in Tokyo Bay, or had never been used at all? Questions employing the word “if” lack rigor, but it is very probable that the use of the atomic bomb only confirmed the Emperor in a decision he had already reached. What distressed him was the destruction of Japanese cities, and every night of good bombing weather brought the obliteration by fire of another city. Hiroshima, Nagasaki, and several other cities had been spared from B-29 raids and therefore offered good atomic-bomb targets. But Truman had no need to use the atomic bomb, and he did not have to invade. General Curtis LeMay had a firm timetable in mind for the 21st Bomber Command; he had told General H. H. (“Hap”) Arnold, the commander in chief of the Army Air Corps, that he expected to destroy all Japanese cities before the end of the fall. Truman need only wait. Steady bombing, the disappearance of one city after another in fire storms, the death of another 100,000 Japanese civilians every week or ten days, would sooner or later have forced the cabinet, the army, and the Emperor to bear the unbearable. Was it right? The bombing of cities in the Second World War was the result of several factors: the desire to strike enemies from afar and thereby avoid the awful trench-war slaughter of 1914–1918; the industrial capacity of the Allies to build great bomber fleets; the ability of German fighters and anti-aircraft to shoot down attacking aircraft that flew by daylight or at low altitudes; the inability of bombers to strike targets accurately from high altitudes; the difficulty of finding all but very large targets (that is, cities) at night; the desire of airmen to prove that air forces were an important military arm; the natural hardening of hearts in wartime; and the relative absence of people willing to ask publicly if bombing civilians was right. “Strategic bombing” got its name between the wars, when it was the subject of much discussion. Stanley Baldwin made a deep impression in the British House of Commons in 1932 when he warned ordinary citizens that bombing would be a conspicuous feature of the next war and that “the bomber will always get through.” This proved to be true, although getting through was not always easy. The Germans soon demonstrated that they could shoot down daytime low-altitude “precision” bombers faster than Britain could build new planes and train new crews. By the second year of the war the British Bomber Command had faced the facts and was flying at night, at high altitudes, to carry out “area bombing.” The second great discovery of the air war was that high-explosive bombs did not do as much damage as fire. Experiments in 1942 on medieval German cities on the Baltic showed that the right approach was high-explosive bombs first, to smash up houses for kindling and break windows for drafts, followed by incendiaries, to set the whole alight. If enough planes attacked a small enough area, they could create a fire storm—a conflagration so intense that it would begin to burn the oxygen in the air, creating hundred-mile-an-hour winds converging on the base of the fire. Hamburg was destroyed in the summer of 1943 in a single night of unspeakable horror that killed perhaps 45,000 Germans. While the British Bomber Command methodically burned Germany under the command of Sir Arthur Harris (called Bomber Harris in the press but Butch—short for “Butcher”—by his own men), the Americans quietly insisted that they would have no part of this slaughter but would instead attack “precision” targets with “pinpoint” bombing. But American confidence was soon eroded by daylight disasters, including the mid-1943 raid on ball-bearing factories in Schweinfurt, in which sixty-three of 230 B-17s were destroyed for only paltry results on the ground. Some Americans continued to criticize British plans for colossal city-busting raids as "baby-killing schemes," but by the end of 1943, discouraged by runs of bad weather and anxious to keep planes in the air, the commander of the American Air Corps authorized bombing “by radar”—that is, attacks on cities, which radar could find through cloud cover. The ferocity of the air war eventually adopted by the United States against Germany was redoubled against Japan, which was even better suited for fire raids, because so much of the housing was of paper and wood, and worse suited for “precision” bombing, because of its awful weather and unpredictable winds at high altitudes. On the night of March 9–10, 1945, General LeMay made a bold experiment: he stripped his B-29s of armament to increase bomb load and flew at low altitudes. As already described, the experiment was a brilliant success. By the time of Hiroshima more than sixty of Japan’s largest cities had been burned, with a death toll in the hundreds of thousands. No nation could long resist destruction on such a scale—a conclusion formally reached by the United States Strategic Bombing Survey in its Summary Report ( Pacific War ): “Japan would have surrendered [by late 1945] even if the atomic bombs had not been dropped, even if Russia had not entered the war [on August 8], and even if no invasion had been planned or contemplated.” Was it right? There is an awkward, evasive cast to the internal official documents of the British and American air war of 1939–1945 that record the shift in targets from factories and power plants and the like toward people in cities. Nowhere was the belief ever baldly confessed that if we killed enough people, they would give up; but that is what was meant by the phrase “morale bombing,” and in the case of Japan it worked. The mayor of Nagasaki recently compared the crime of the destruction of his city to the genocide of the Holocaust, but whereas comparisons—and especially this one—are invidious, how could the killing of 100,000 civilians in a day for a political purpose ever be considered anything but a crime? Fifty years of argument over the crime against Hiroshima and Nagasaki has disguised the fact that the American war against Japan was ended by a larger crime in which the atomic bombings were only a late innovation—the killing of so many civilians that the Emperor and his cabinet eventually found the courage to give up. Americans are still painfully divided over the right words to describe the brutal campaign of terror that ended the war, but it is instructive that those who criticize the atomic bombings most severely have never gone on to condemn all the bombing. In effect, they give themselves permission to condemn one crime (Hiroshima) while enjoying the benefits of another (the conventional bombing that ended the war). Ending the war was not the only result of the bombing. The scale of the attacks and the suffering and destruction they caused also broke the warrior spirit of Japan, bringing to a close a century of uncontrolled militarism. The undisguisable horror of the bombing must also be given credit for the following fifty years in which no atomic bombs were used, and in which there was no major war between great powers. It is this combination of horror and good results that accounts for the American ambivalence about Hiroshima. It is part of the American national gospel that the end never justifies the means, and yet it is undeniable that the end—stopping the war with Japan—was the immediate result of brutal means. Was it right? When I started to write this article, I thought it would be easy enough to find a few suitable sentences for the final paragraph when the time came, but in fact it is not. What I think and what I feel are not quite in harmony. It was the horror of Hiroshima and fear of its repetition on a vastly greater scale which alarmed me when I first began to write about nuclear weapons (often in these pages), fifteen years ago. Now I find I have completed some kind of ghastly circle. Several things explain this. One of them is my inability to see any significant distinction between the destruction of Tokyo and the destruction of Hiroshima. If either is a crime, then surely both are. I was scornful once of Truman’s refusal to admit fully what he was doing; calling Hiroshima an army base seemed a cruel joke. Now I confess sympathy for the man—responsible for the Americans who would have to invade; conscious as well of the Japanese who would die in a battle for the home islands; wielding a weapon of vast power; knowing that Japan had already been brought to the brink of surrender. It was the weapon he had. He did what he thought was right, and the war ended, the killing stopped, Japan was transformed and redeemed, fifty years followed in which this kind of killing was never repeated. It is sadness, not scorn, that I feel now when I think of Truman's telling himself he was not “killing ‘all those kids.’” The bombing was cruel, but it ended a greater, longer cruelty. They say that the fiftieth anniversaries of great events are the last. Soon after that the people who took part in them are all dead, and the young have their own history to think about, and the old questions become academic. It will be a relief to move on.

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Bombing of Hiroshima and Nagasaki

By: History.com Editors

Updated: April 18, 2023 | Original: November 18, 2009

On August 6, 1945, during World War II (1939-45), an American B-29 bomber dropped the world’s first deployed atomic bomb over the Japanese city of Hiroshima. The explosion immediately killed an estimated 80,000 people; tens of thousands more would later die of radiation exposure. Three days later, a second B-29 dropped another A-bomb on Nagasaki, killing an estimated 40,000 people. Japan’s Emperor Hirohito announced his country’s unconditional surrender in World War II in a radio address on August 15, citing the devastating power of “a new and most cruel bomb.”

The Manhattan Project

Even before the outbreak of war in 1939, a group of American scientists—many of them refugees from fascist regimes in Europe—became concerned with nuclear weapons research being conducted in Nazi Germany . In 1940, the U.S. government began funding its own atomic weapons development program, which came under the joint responsibility of the Office of Scientific Research and Development and the War Department after the U.S. entry into World War II . The U.S. Army Corps of Engineers was tasked with spearheading the construction of the vast facilities necessary for the top-secret program, codenamed “The Manhattan Project ” (for the engineering corps’ Manhattan district).

Over the next several years, the program’s scientists worked on producing the key materials for nuclear fission—uranium-235 and plutonium (Pu-239). They sent them to Los Alamos, New Mexico , where a team led by J. Robert Oppenheimer worked to turn these materials into a workable atomic bomb. Early on the morning of July 16, 1945, the Manhattan Project held its first successful test of an atomic device —a plutonium bomb—at the Trinity test site at Alamogordo, New Mexico.

No Surrender for the Japanese

By the time of the Trinity test, the Allied powers had already defeated Germany in Europe . Japan, however, vowed to fight to the bitter end in the Pacific, despite clear indications (as early as 1944) that they had little chance of winning. In fact, between mid-April 1945 (when President Harry Truman took office) and mid-July, Japanese forces inflicted Allied casualties totaling nearly half those suffered in three full years of war in the Pacific, proving that Japan had become even more deadly when faced with defeat. In late July, Japan’s militarist government rejected the Allied demand for surrender put forth in the Potsdam Declaration, which threatened the Japanese with “prompt and utter destruction” if they refused.

General Douglas MacArthur and other top military commanders favored continuing the conventional bombing of Japan already in effect and following up with a massive invasion, codenamed “Operation Downfall.” They advised Truman that such an invasion would result in U.S. casualties of up to 1 million. In order to avoid such a high casualty rate, Truman decided–over the moral reservations of Secretary of War Henry Stimson, General Dwight Eisenhower and a number of the Manhattan Project scientists–to use the atomic bomb in the hopes of bringing the war to a quick end. Proponents of the A-bomb—such as James Byrnes, Truman’s secretary of state—believed that its devastating power would not only end the war, but also put the U.S. in a dominant position to determine the course of the postwar world.

Why Did the U.S. Bomb Hiroshima and Nagasaki?

Hiroshima, a manufacturing center of some 350,000 people located about 500 miles from Tokyo, was selected as the first target. After arriving at the U.S. base on the Pacific island of Tinian, the more than 9,000-pound uranium-235 bomb was loaded aboard a modified B-29 bomber christened Enola Gay (after the mother of its pilot, Colonel Paul Tibbets). The plane dropped the bomb—known as “Little Boy”—by parachute at 8:15 in the morning, and it exploded 2,000 feet above Hiroshima in a blast equal to 12-15,000 tons of TNT, destroying five square miles of the city.

Hiroshima’s devastation failed to elicit immediate Japanese surrender, however, and on August 9 Major Charles Sweeney flew another B-29 bomber, Bockscar , from Tinian. Thick clouds over the primary target, the city of Kokura, drove Sweeney to a secondary target, Nagasaki, where the plutonium bomb “Fat Man” was dropped at 11:02 that morning. More powerful than the one used at Hiroshima, the bomb weighed nearly 10,000 pounds and was built to produce a 22-kiloton blast. The topography of Nagasaki, which was nestled in narrow valleys between mountains, reduced the bomb’s effect, limiting the destruction to 2.6 square miles.

HISTORY Vault: Hiroshima - 75 Years Later

Marking the anniversary of the 1945 Hiroshima bombing, this special—told entirely from the first-person perspective of leaders, physicists, soldiers and survivors—provides a unique understanding of the most devastating experiment in human history.

Aftermath of the Bombing

At noon on August 15, 1945 (Japanese time), Emperor Hirohito announced his country’s surrender in a radio broadcast. The news spread quickly, and “Victory in Japan” or “V-J Day” celebrations broke out across the United States and other Allied nations. The formal surrender agreement was signed on September 2, aboard the U.S. battleship Missouri, anchored in Tokyo Bay.

Because of the extent of the devastation and chaos—including the fact that much of the two cities' infrastructure was wiped out—exact death tolls from the bombing of Hiroshima and Nagasaki remain unknown. However, it's estimated roughly 70,000 to 135,000 people died in Hiroshima and 60,000 to 80,000 people died in Nagasaki, both from acute exposure to the blasts and from long-term side effects of radiation. 

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National Archives News

The Atomic Bombing of Hiroshima and Nagasaki, August 1945

Photograph of Hiroshima after the atomic bomb. (National Archives Identifier 22345671 )

The United States bombings of the Japanese cities of Hiroshima and Nagasaki on August 6 and August 9, 1945, were the first instances of atomic bombs used against humans, killing tens of thousands of people, obliterating the cities, and contributing to the end of World War II. The National Archives maintains the documents that trace the evolution of the project to develop the bombs, their use in 1945, and the aftermath.

Online Exhibits

The Atomic Bombing of Hiroshima and Nagasaki   features a letter written by Luis Alvarez, a physicist who worked on the Manhattan Project, on August 6, 1945, after the first atomic bomb was dropped on Hiroshima, Japan.

[Photograph: The atomic cloud rising over Nagasaki, Japan, August 9, 1945. National Archives Identifier 535795 ]

A People at War looks at the 509 Composite Group, the unit selected to carry the atomic bomb to Hiroshima.

[Photograph: Col. Paul Tibbets, Jr., waves from the cockpit of the Enola Gay before departing for Hiroshima, August 6, 1945. National Archives Identifier  535737 ]

Photograph Gallery

"Little Boy" atomic bomb being raised into plane on Tinian Island before the flight to Hiroshima. National Archives Identifier  76048583

Hiroshima after the atomic bomb. National Archives Identifier  22345671

Hiroshima after the atomic bomb. National Archives Identifier  22345679

Hiroshima after the atomic bomb. National Archives Identifier  22345680

Hiroshima after the atomic bomb. National Archives Identifier  148728174

Nuclear weapon of the "Fat Man" type, the kind detonated over Nagasaki, Japan. National Archives Identifier  175539928

The atomic cloud rising over Nagasaki, Japan. National Archives Identifier  535795

Nagasaki after the atomic bomb. National Archives Identifier  39147824

Nagasaki after the atomic bomb. National Archives Identifier  39147850

Additional Photographs

Atomic Bomb Preparations at Tinian Island, 1945

Photographs used in the report Effects of the Atomic Bomb on Hiroshima, Japan

Manhattan Project Notebook

Atomic bomb/Enola Gay preparations for the bombing missions

Post-bombing aerial and on-the-ground images of Hiroshima

Empty bottle of Chianti Bertolli wine signed by scientists who worked on the Manhattan Project

Archival Film

Hiroshima and Nagasaki Effects, 1945

The Last Bomb ,  a 1945 film, done in Technicolor, by the Army Air Forces Combat Camera Units and Motion Picture Units covering the B-29 bombing raids on Japan

Effects on the human body of radiation from the atomic bomb

Additional Records

Photos: Atomic Bomb Preparations at Tinian Island, 1945

Atomic bomb/ Enola Gay preparations for the bombing missions

Post-Hiroshima bombing aerial and on-the-ground images

Color image of Hiroshima after bombing

Manhattan Project records from Oak Ridge, TN

Blogs and Social Media Posts

Unwritten Record:  Atomic Bombings of Hiroshima and Nagasaki

Unwritten Record:  Witness to Destruction: Photographs and Sound Recordings Documenting the Hiroshima Bombing

Forward with Roosevelt:  Found in the Archives: The Einstein Letter

Pieces of History:  Little Boy: The First Atomic Bomb

Pieces of History:  Harry Truman and the Bomb

Pieces of History:  Morgantown Ordnance Works (part of the Manhattan Project) Panoramas, 1940–1942

Today's Document:  Petition from Manhattan Project Scientists to President Truman

For Educators

Docs Teach resources on the atomic bomb

Teaching with Documents:  Photographs and Pamphlet about Nuclear Fallout

Kennedy Library: “The Presidency in the Nuclear Age”

At the Presidential Libraries

Roosevelt Library: Albert Einstein’s letter to FDR regarding the atomic bomb

Truman Library: “The Decision to Drop the Atomic Bomb ”

Truman Library: Additional records on the bombing of Hiroshima

Truman Library:  President Truman's Diary Entry for July 17, 1945 (the day before Truman learned that the United States had successfully tested the world's first atomic bomb)

Truman Library: Memo for the Record, Manhattan Project, July 20, 1945

Truman Library: Petition from Leo Szilard and other scientists to President Truman

Eisenhower Library: Atoms for Peace

Kennedy Library: “ The Presidency in the Nuclear Age: The Race to Build the Bomb and the Decision to Use It”

Home — Essay Samples — History — Hiroshima — A Discussion of Whether The US Bombing of Hiroshima and Nagasaki Was Justified

A Discussion of Whether The Us Bombing of Hiroshima and Nagasaki Was Justified

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Published: Nov 6, 2018

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Was the United States Justified in Using the Atomic Bomb?

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Reasons why Bombing Japan was not justified Essay

Introduction, works cited.

The dropping of the atomic bombs on Hiroshima and Nagasaki are still one of the most controversial happenings in recent history. Historians have passionately debated whether the bombings were essential, the effect that they had in ending the war in the Pacific Region, and what other alternatives were on hand for the United States.

These very same questions were also debatable during that time, as American decision makers deliberated on how to put to use powerful new technology and what the long-term impact of atomic weaponry would be on the Japanese (Hasegawa 96). This essay presents a debate on reasons why the U.S. was not justified in using the atomic bomb on Japan.

Most historians who have been taking part in the debate on how World War II ended have based much of their focus on why the U.S. decided to drop the atomic bomb. Despite the much emphasis placed on this matter, there has been little attention directed on the role played by the Japanese in ending the war.

Even less information is available on soviet-decision-making and their joining the war against Japan. One of the major obstacles, which were overcome only recently, was the absence of a historian who was fluent in English, Japanese and Russian to enable him to examine the major materials, which included government, military, and intelligence memos and reports in all the three languages. This explains in part why most of the available literature on the subject only touches on the American side of the story.

One of the reasons why bombing Japan was not justified is because America had other options, which they could have used to compel Japan to surrender. In his 2005 milestone study titled Racing the Enemy: Stalin, Truman, and the Surrender of Japan , historian Tsuyoshi Hasegawa critically examines the threefold wartime relationship between America, Japan, and the Soviet Union.

What comes out from this careful study is the fact that America had other options that they could have pursued instead of the bombings but which they chose to ignore. According to Hasegawa (100), the Soviet leader Joseph Stalin had indicated to America that he would attack Japan on 15 August 1945.

This meant that America had up to 15 th August to force Japan to surrender in order to prevent the Soviet union from joining the war something that would make Truman and his government to appear weak. Contrary to the claim that Americans used the bomb as a last resort, Hasegawa disagrees and claims that the early August date was chosen to counter the Soviets’ impeding attack in order to prevent them from joining the war.

In fact, the diligent research done by Hasegawa dispels the notion that the bombings weakened Japan’s position thus leading to their surrender.

According to the historian, the myth that the bombings weakened Japan’s will to fight and that they saved both Japanese and American soldiers is only meant to justify Truman’s decision and help in easing the conscience of the American people. According to Hasegawa, this myth lacks any historical backing since there is enough evidence to show that there were other alternatives besides the use of the bombs but Truman and his administration chose to ignore them.

Historians claim that Truman’s main worry was that allowing Stalin to enter the war would be an important strategic gain for him and this would pose a big threat to American interests in the region. With a deadline to beat, the only option that remained for Truman and his administration was to use the atomic bomb (Hasegawa 101).

Although Japan had not yet given a public indication that it intended to surrender, insiders knew that the country could not continue with the war and surrender was imminent.

This admission is contained in intelligence reports showing that Truman was privy to information that Japan had abandoned its goal of victory and was instead planning on how to harmonize its national pride with losing the war. With this kind of information, it is clear that America had no justification whatsoever to use the bombs since it was only a matter of time before the Japanese admitted defeat.

The second reason that makes the American bombing unjustified is the deeply flawed casualty claims. As it is, the exact number of Allied and Japanese lives that were likely to be lost during the intended invasion remains unknown. However, it is evident that those who supported the bombing have escalated the prediction of those who could have died from the earlier prediction of 45,000 given by the U.S. War Department.

Ten years after the bombings, Truman claimed that George Marshall feared losing close to a half million soldiers if the war was not brought to an abrupt close. This contradicted the claims by Stimson the Secretary of War who two years after the war had claimed that over a million people were dead, wounded, or missing.

In a 1991 address to congress, George Bush claimed that Truman’s decision to drop the bomb ‘spared’ millions of American lives. Four years after the claims by Bush, a crewmember of Bock’s car, the plane that dropped one of the bombs stated that the bombing preserved the lives of over six million people.

Over the years, historians have provided evidence to show that the casualty figures offered by Truman and his bombing supporters were seriously flawed. One historian claimed that the people who supported the high casualty claims relied upon strained readings and omitted crucial material, which in effect limited their research and cast a shadow of doubt on their findings.

Hasegawa and other anti-bombing historians did not refute the claim that Truman was concerned at the possibility of America losing many lives during the invasion, but the projected numbers were way below the exaggerated figures provided after the war to rationalize the bombings.

Such inflated figures, along with Japan’s presumed rejection of surrendering is usually a part of the debate on why the atomic bombs were necessary but from the proffered evidence, these claims are highly questionable.

Another reason to prove that the bombing was not justified is derived from looking at the real reasons why Japan surrendered. According to political analysts, postwar interviews with numerous Japanese military and civilian leaders showed that Japan could have given in before November 1, which is the date that the U.S. had planned to invade the country.

This was not because Japan was afraid of atomic bombs or the impeding Soviet entry but because they had no reason to continue fighting in a war, which they were certain to lose. This conclusion definitely supports the view that the bombings were not in any way necessary to end the war and their use was therefore unjustified.

Historians project that given the huge impact that the Soviet entry into the war and the air-naval blockade imposed by the Allied forces, there is high possibility that Japan would have surrendered before any invasion since its resources to support the war had dwindled. Historians question why Truman was not willing to avoid the costly invasion of Japan by allowing the Soviet entry instead of dropping the bombs.

The question of Truman and his administration not knowing about Japan’s intention to surrender does not arise since historians have discovered records showing that Truman was in possession of intercepted and decoded Japanese intelligence communication, which showed their willingness to surrender.

As Hasegawa (110) rightly put it, if Truman and his ilk really wanted to desist from using the atomic bomb as it was claimed after the war, then why was the intelligence reports in the intercepted cables ignored? According to the historian, stressing the decisive role of the atomic bombs in ending the war was meant to weaken the importance of soviet entry into the war thus making inconsequential the Soviet role in ending the war. This was meant to display the super weapon that was only possessed by the United States.

The dropping of the atomic bombs on Hiroshima (August 6, 1945) and Nagasaki (August 9, 1945) is still one of the most debated topics in modern history. According to most historians, the bombings were unjustified because there were other available options to end the war but they were ignored.

Contrary to the claim that Americans used the bomb as a last resort, most historians disagree and claim that the early August date was chosen to counter the Soviets’ impeding attack on August 15 1945. This ensured that America got the credit for ending the war.

Hasegawa, Tsuyoshi. Racing the Enemy: Stalin, Truman, and the Surrender of Japan . Harvard University Press, 2005. 89-112. Print.

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"Reasons why Bombing Japan was not justified." IvyPanda , 30 Nov. 2023, ivypanda.com/essays/reasons-why-bombing-japan-was-not-justified/.

IvyPanda . (2023) 'Reasons why Bombing Japan was not justified'. 30 November.

IvyPanda . 2023. "Reasons why Bombing Japan was not justified." November 30, 2023. https://ivypanda.com/essays/reasons-why-bombing-japan-was-not-justified/.

1. IvyPanda . "Reasons why Bombing Japan was not justified." November 30, 2023. https://ivypanda.com/essays/reasons-why-bombing-japan-was-not-justified/.

Bibliography

IvyPanda . "Reasons why Bombing Japan was not justified." November 30, 2023. https://ivypanda.com/essays/reasons-why-bombing-japan-was-not-justified/.

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Atomic Bomb Justified

On August 6th, 1945, an American B-29 bomber named “Enola Gay” dropped the world’s first Atomic bomb on Hiroshima in Japan. The nuclear explosion killed nearly 90 percent of the cities population, killing 75,000 people from the point of impact and thousands more dying from Radiation Poisoning later on. Three days later, on August 9th, a second B-29 bomber named “Bockscar” dropped a second Atomic bomb on the Japanese city, Nagasaki. This bomb killed 40,000 people on impact with over 60,000 more people dying after from Radiation Poisoning.

The Atomic bomb was a new technology to everyone worldwide and its raw destructive power was enough for the Japanese Emperor Hirohito to agree to the Americans unconditional surrender terms. The terms were to release all prisoners of war, end the fighting and to agree with the Potsdam declaration. Perspective 1: Michihiko Hachiya – Japanese Michihiko Hachiya was Medical Practitioner who survived the Hiroshima bombing in 1945 and kept a diary of his experience. Hachiya’s diary covers the period from August 6 1945 to September 30 August.

Hachiya describes the effects of the Atomic bomb blast from its first flash early in the morning as he rested from his night shift at the hospital. The force of the blast stripped all the clothes from his body, but his wife and him survived. They both received serious burns to their bodies from the Nuclear Radiation. Hachiya said when he was in the hospital everything was quiet, he adds to that by saying linguistic silence sometimes is necessary for victims. Mainly because it’s a psychological reaction to an extreme situation with which humans cannot cope.

He explains it, “Kind of like a psychic numbing, in which victims cannot find an adequate emotional response to the apocalyptic imagery they receive. ” Hachiya emphasizes the horrific nature of the event behind the general atmosphere of inarticulacy. Hachiya said himself and many people thought that when the Atomic bomb went off that the apocalypse had started, they genuinely thought it was the end of the world . Hachiya spent many hours after the bomb had went off in the hospital helping the injured and wounded.

Many people didn’t know what had happened, but as information surfaced about a bomb, many people started to realise what had really happened. Hachiya was disgusted at what the Americans had done. He later mentions in his diary that him and the people around him felt like they were rats in a lab experiment, and to make it worse the Americans didn’t even know what the radiation would do. Hachiya was a Medicinae Doctor and had a basic understanding of what radiation was, but not to the level that was delivered by the bomb.

Hachiya was disgusted that the Americans would use such an Avant Garde technology and the fact they didn’t know the capability of its damage, infuriated him further. Hachiya believes that the Americans didn’t need to drop the bomb to stop the war, they just needed to give it time. He believes everything would have sorted itself out, with not many more lives lost. “It is as in a bad dream, I see shadows come, species ghosts walking with outstretched arms, I wonder why, why did they need to do this to my people. ” Hachiya compares the bombing to a bad dream , therefore reinforcing his disliking of what occurred.

Hachiya said in his diary that he had so many questions. He wanted to know why the Americans thought it was justified to do what they did. Why were they willing to kill so many people just to save their own, and Why did they use a Nuclear bomb when they didn’t know what the repercussions would be. When Hachiya found out that the Americans thought that killing thousands of Japanese would save up to a million American soldiers and that was a justifiable reason to drop the bomb, he was absolutely outraged. He couldn’t wrap his head around the fact that the Americans were willing to kill civilians just to save their own. I had this numb feeling, nothing would come out of my mouth, there was complete silence, nothing could describe how I felt. ”

Hachiya has a biased perspective towards the Japanese, as he is Japanese and was in Hiroshima, Japan when the bomb was dropped. Hachiya holds this perspective because he is Japanese and the bomb directly affected his life and the people around him. Hachiya was punished by the bomb and all its after effects because of something that he had no control over. Hachiya did understand what the Japanese were doing in World War 2, but he doesn’t believe the Americans retaliation was justified or necessary.

As Hachiya was a doctor he was concerned for all his patients and all the work he would have to do caused by the aftermath. He was very busy for the following weeks attending to the injured and sick. This is when he gained further knowledge that it was a radiation bomb. As he was the senior doctor at the hospital, he was also in charge of all the other doctors, which was a burden on him. Perspective 2: Henry L. Stimson – American Henry L. Stimson was an American Statesman, Lawyer and a Republican Party Politician.

Stimson served under Democrats Franklin D. Roosevelt and Harry S. Truman. During World War II he took charge of raising and training 13 million soldiers and airmen, supervised the spending of a third of the nation’s GDP on the Army and the Air Forces, helped formulate military strategy, and oversaw the building and use of the atomic bombs. In the early stages of World War 2 Stimson added a note in his diary saying, “Roosevelt brought up the event that we are likely to be attacked perhaps next Monday, for the Japanese are notorious for making an attack without warning, and the question was what we should do.

The question was how we should maneuver them into the position of firing the first shot without allowing too much danger to ourselves. ” From this entry Stimson confirms that roosevelt has a feeling that the Japanese were going to attack. In the days leading upto the bombs being dropped it is believed that Truman never signed anything official to allow the bombs to be dropped, they were just dropped with no signed confirmation. In the part of the war Stimson was Truman’s right hand man, his go to guy with hard situations like this.

When talking to Stimson about whether it is ethical to drop the bomb Truman was reportedly very keen to test out his country’s new technology, even without knowing the repercussions. Stimson was also keen to use the bomb, so with having his right hand man on his side Truman was set on using them. Stimson’s quote aimed at Truman; “The President so far has struck me as a man who is trying hard to keep his balance. He certainly has been very receptive to all my efforts in these directions. ”

As Stimson was Secretary of War, he was directed as the leader of the Manhattan Project by Harry Truman. The Manhattan Project was a research and development project that produced the first nuclear weapons during World War II. It was led by the United States with the support of the United Kingdom and Canada. The Americans got their best scientists to try and develop a new destructive technology to give them the upper hand in wars . There scientists succeeded and developed the world’s first Nuclear bombs. They had two varients, a Uranium bomb and a Plutonium.

The Uranium bomb was used on Hiroshima and the Plutonium dropped on Nagasaki. Stimson got a lot of appraisal as the bombs were ready for use in early 1945 and they were needed only a couple months later. Everyone saw Stimson as a hero as he was able to get the bombs developed in time for use. Henry was happy to have been apart of the development of the bombs that urged the Japanese to surrender. Stimson saw the attacks on Hiroshima and Nagasaki as payback for the Japanese attack on Pearl harbour earlier in the war, As said in the Harper’s Magazine article.

But I think the bomb instead constitutes merely a first step in a new control by man over the forces of nature too revolutionary and dangerous to fit into old concepts. ” But it wasn’t only Stimson that saw it as backpack, Harry Truman also viewed it is partial payback for what the Japanese did at Pearl Harbour. Stimson said this is one of the main reasons that the bombs being dropped was justified and worth it. In the Harper’s Magazine, Stimson stated that by using the new Atomic Bombs , would save up to one million lives if used. The Americans estimated that if they used the bombs it would save one million Americans, this is just soldiers.

It would save future soldiers that would be enlisted to fight. Stimson said saving one million lives is worth killing over 100,000 people , especially because they would have been American. And with them saving over one million lives means that it was 100 percent justified to drop the bombs. Stimson was American, so he had a bias towards the Americans in the war. Stimson was Truman’s right hand man and had a direct say in whether the bombs should’ve been dropped or not. He wants to use the bombs to see how effective the new technology was and if they had succeeded in their making of the atomic bomb.

He also estimated that the bomb would save over one million lives in the future if the bomb was dropped, that was enough justification for him to give the go ahead for the bombs to be used. Perspective 3: My Perspective I believe that the Americans choice to drop the atomic bomb was not justified. They said that it would save up to a million lives if dropped, and that was their main motive to use it. But they had no way of proving that it would save upto one million people. I believe that was a copout to use the bomb.

I also honestly believe that Harry Truman was also desperate to test out the Atomic bomb , therefore pushing for the bombs to be tested on Japan. Truman had been pushing his officials to agree with him that dropping the atomic bombs was good, and would help the Americans and their allies win the war. “I realize the tragic significance of the atomic bomb.. . having found the bomb, we have used it. We have used it against those who attacked us without warning at Pearl Harbor , against those who have starved and beaten and executed American prisoners of war, against those who have abandoned all pretense of obeying international laws of warfare.

We have used it in order to shorten the agony of young Americans. We shall continue to use it until we completely destroy Japan’s power to make war. Only a Japanese surrender will stop us. ” I believe that in this quote, Truman is trying to play the sympathy card, trying to get people to genuinely think that he didn’t want to use the bomb, but in the end of the day the compiled evidence showing that he was wanting to drop the bomb points towards everything saying he did. As mentioned in the quote above, Truman sees the dropping of the two bombs as payback for Pearl Harbour.

So with motives to get payback they used the new atomic technology. He wanted to get revenge for the attack on Pearl harbour by the Japanese earlier in World War 2. He also wants to get revenge for all the American people who starved, got beaten and executed as prisoners of war. From what I can see from this, is that Truman wasn’t worried about making sure he would save future American soldiers lives, but it was an attempt at getting stone cold revenge. But if you think about it an American president should not be seeking revenge.

I find that distasteful. So in the big picture, Truman wants revenge and Stimson wants to save future civilians. But in this case obviously Truman got the final choice as he was the President at the time and Stimson was only the Secretary of War. But if you think about it, that was the perspectives they wanted the public to know about. I think that they were both eager to try out the new atomic bomb . By them using the bomb it also gave them an upperhand in wars as people would find out that they have this new deadly technology and were willing to use it.

It was an intimidation tactic, and they executed it considering the bombs pretty much ended the war. To sum everything up, I believe the it was not reasonable or justified for the Americans to use the new founded Atomic technology on the Japanese. Mainly because they didn’t know enough about it to understand the damage it could and would do. From the evidence I’ve seen, it is pretty obvious that the Americans were keen on testing out the bombs and therefore went through with the act. It was inhumane and not necessary to use such a avant garde technology. I believe the bombing of Hiroshima and Nagasaki should never have happened.

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War History Online

Ending the Deadliest Conflict in Human History: Why Did Japan Surrender in World War II?

Posted: April 15, 2024 | Last updated: April 15, 2024

The Japanese surrender in World War II brought to a close one of the darkest and deadliest chapters in human history. While the Germans waved the white flag in May 1945, it took the Empire of Japan several more months to admit they'd been defeated. Most believe the atomic bombings of Hiroshima and Nagasaki were the only reason the country surrendered, but, in reality, there were several factors at play.

Atomic bombings of Hiroshima and Nagasaki

Two key events that led to Japan's surrender were the atomic bombings on Hiroshima and Nagasaki . On the morning of August 6, 1945, the former was subjected to an attack that decimated the city and inflicted a devastating human toll, with between 90,000-146,000 killed both during Little Boy 's detonation and after, due to the effects of radiation exposure and burns to the skin.

Just three days later, on August 9, Nagasaki experienced a similar fate, with the Boeing B-29 Superfortress Bockscar dropping the atomic bomb Fat Man on the city, located some 261 miles from Hiroshima. Just like the latter, Nagasaki suffered extensive losses, with between 60,000-80,000 citizens perishing within four months of the attack.

Between both detonations, it's estimated around 129,000-226,000 people lost their lives - a truly devastating number.

The atomic bombs not only demonstrated the US military's superiority, but also signalled the emergence of a new and terrifying era in warfare. The realization that further nuclear attacks could obliterate Japanese cities forced leadership to reconsider their position; the fear of additional devastation, coupled with the understanding that conventional defenses were futile against such power, significantly influenced Japan's decision to surrender.

Declaration of war by the Soviet Union

Compounding the despair following the atomic bombings, the Soviet Union's declaration of war against Japan on August 8, 1945, dealt yet another severe blow to the Japanese military's hopes. Officials hadn't believed the Red Army to be much of a threat, with it assumed the Imperial Japanese Army (IJA) wouldn't have to face Joseph Stalin 's soldiers until Spring 1946. Emperor Hirohito had also previously requested  the Soviet dictator act as an intermediary between Japan and the United States.

As a result, the Japanese military and Hirohito were shocked by the sudden Soviet invasion of Manchuria , which saw 650 of the 850 troops occupying the region killed or wounded in the first two days of combat. This declaration of war by the Soviet Union eradicated any hope Japan had for a mediated peace and highlighted the nation's growing geopolitical isolation.

Faced with the prospect of a two-front war, Japanese leaders recognized the futility of their situation - Hirohito himself even begged military officials to reconsider a surrender.

Japan's military resources were beginning to dwindle

By 1945, Japan found itself in an increasingly untenable position. Years of sustained conflict had severely diminished its military capabilities, with the United States particularly to blame. The country's strategic island-hopping campaign had effectively isolated Japan, severing its connections to occupied territories in the Pacific. This isolation was compounded by a stringent naval blockade and a relentless aerial bombing campaign that targeted Japanese cities and industrial centers, crippling the nation's war effort.

The scarcity of vital resources caused by this led to widespread suffering and hardship among the Japanese populace. Food and fuel shortages became acute, with the average civilian's caloric intake dropping to an unhealthy 1,680 per day. There was also a shortage in working-age males, given the majority of those able to fight had been recruited into the military.

The realization that the war was unwinnable, given the dire state of the nation's military and resources, became a key factor in leadership's decision to surrender.

Japan wanted to preserve its Emperor system

A unique aspect of Japan's surrender negotiations was the desire to preserve the emperor system; the government insisted on maintaining the position as a non-negotiable term. The fear that unconditional surrender would lead to the dismantling of the monarchy was a significant concern, influencing the decision-making process at the highest levels.

What ultimately came from the discussions was the " Humanity Declaration ," in which Hirohito agreed to a "Symbolic" emperor system, which saw a denial of the emperor's divinity and, instead, positioned him as "the symbol of the State and of the unity of the people."

Essentially, the emperor, while still a figurehead, would no longer hold the most political power. Instead, a new constitution would be adopted.

Facilitating Japan's surrender

The process of facilitating Japan's surrender was marked by significant diplomatic and communicative efforts. Behind the scenes, diplomats and intermediaries worked tirelessly to establish a channel of communication between Japan and the Allied forces. These efforts were aimed at finding a mutually acceptable solution that would allow the country to surrender while addressing the concerns of all parties involved.

With all the aforementioned factors piling on top of the each other, the decision was ultimately made for Japan to surrender, with Emperor Hirohito announcing the news to the public via a radio broadcast on August 15, 1945.

The first time he'd spoken to average citizens directly, the emperor explained , "The war has lasted for nearly four years. Despite the best that has been done by everyone - the gallant fighting of the military and naval forces, the diligence and assiduity of our servants of the state, and the devoted service of our one hundred million people - the war situation has developed not necessarily to Japan's advantage, while the general trends of the world have turned against her interest."

More from us: Paul Tibbets Dropped the Atomic Bomb on Hiroshima and Was Given No Funeral or Gravestone

Just over two weeks later, aboard the American battleship USS Missouri (BB-63), the Japanese Instrument of Surrender was signed. Those present included representatives from the Empire of Japan and the Allied nations, with the most notable being Gen. Douglas MacArthur, Fleet Adm. Chester Nimitz and Chief of the Japanese Army General Staff Gen. Yoshijirō Umezu.

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