Was the 1945 nuclear attack on Nagasaki a military priority?

Nagasaki before and after the bomb

IB History HL Internal Assessment


 Section A - Plan of Investigation (224 words)

    In order to investigate the question "Was the 1945 nuclear attack on Nagasaki a military priority?" one must consider the origin of the Manhattan project, President Truman's official military reasons for using atomic weapons, why it was decided to launch the bomb instead of an invasion and why Nagasaki was chosen as a target. In addition, it is important to observe Japan's capability to continue the war, its policies prior to and following the nuclear attacks and whether weapon impacted capitulation. Alternate reasons for accepting defeat will also be discussed in order to conclude if the Nagasaki bomb facilitated defeat and was therefore a military priority; the moral implications of the attack will not be considered.
    Evidence has been extracted from a variety of primary sources including Truman's diaries, telegrams and other military documents relating to the bombing. In particular, Stimson's justification of the attacks was crucial to this investigation because his strong personal control over the Manhattan project suggests understanding of both U.S. reasons for the bombing as well as the facts the USA wanted to propagate. Secondary material such as books and websites were selected as to how they supported or contradicted Stimson's view: Gordin's 2005 analysis was a useful source as his revisionist perspective presented alternative factors for Japanese surrender, arguing that the nuclear weapons were not necessary to induce defeat.

Section B - Summary of Evidence (647 words)

    The development of the atomic bomb under the U.S. Manhattan Project began in 1942 in case it would be of use against Germany. Following Germany's defeat in May 1945,  the weapon came into consideration for ending the Pacific War against Japan.
    Japan already perceived itself as a defeated nation: beginning in early 1945, the U.S. naval blockade imposed on Japan had diminished its industry, food supply and ability to continue fighting. Between July 11-26, the U.S. intercepted Japanese telegraphs expressing a hope to "terminate the war" with Russia helping to negotiate an favourable peace. However, the Potsdam Proclamation, issued on July 26, called for unconditional surrender including the removal of the emperor system. This was rejected because Japan wished to maintain its sovereignty, subsequently adopting the policy of fighting aggressively in the hope of discouraging the U.S. from invading until peace was declared.
    As a result, the U.S. anticipated a costly victory  and did not want to commit to a lengthy  invasion. Truman estimated a potential loss of  500,000 lives,  writing in his diary that he aimed for the bombs to "completely destroy Japan's power to make war... [shortening] the agony of war".  The Hiroshima attack on August 6 did not prove to be decisive: Japan did not surrender nor seem pressured by the nuclear attack.
    The choice to target Nagasaki was dictated by weather conditions preventing the planned attack on Kokura. Nagasaki was considered important as it was a major harbour, a densely populated area and home to heavy industry such as Mitsubishi factories, maximising the bomb's destructive potential. As an ancient city and religious centre with high literacy levels, it was anticipated that its residents would be "better able to appreciate the significance of the weapon", indicating that Nagasaki was chosen as a secondary target in order to exploit the psychological terror of the bombing. 
    On August 9, Nagasaki was bombed, killing 35,000 to 40,000 people. Following Hiroshima's death toll of 70,000, the Nagasaki bomb is said to have confirmed surrender: Emperor Hirohito believed that the emergence of "such a new weapon" made it "less possible" for Japan to continue the war  and the chief cabinet secretary later stated that the war could have ended in a similar way even if the Soviets had remained neutral .  American statesman Henry L. Stimson wrote in 1947 that the bomb had succeeded as a psychological weapon in bringing about Japanese surrender.
    The Japanese government, led by the war party, claimed that it would "never surrender as a result of air raids” even after the events of Nagasaki. As Hiroshima had not provoked surrender, U.S. decision-makers doubted that a second attack would be able to end the war immediately and anticipated that at least a third would be necessary before launching the scheduled invasion on November 1. At most, it was hoped that the war would be shortened by several months. While the bomb's scientific success was praised immediately, the role of the weapon in ending the war was emphasised only after Japan had surrendered. Prior to his, the U.S war cabinet similarly equated the bomb to previous firebombing campaigns.
    The Soviet declaration of war on Japan exerted pressure the bomb had not, causing the Emperor to urge the government to accept the Potsdam Declaration and surrender.  Its involvement meant that Japan could be fighting a two-front war as Soviets, already situated in Japanese-held Manchuria, were ordered to attack Japan's northern and southern isles. This influenced Japan's unconditional surrender as no strategy remained and it could no longer hope for the Soviet Union to mediate for an acceptable peace.
    On August 15, Japan accepted surrender based on Potsdam terms.

Section C - Evaluation of Sources (391 words)

Source A -  Five Days in August: How World War II Became a Nuclear War by Michael D. Gordin
Written by a professor of history at Princeton University in 2005, the source is a revisionist interpretation sixty years after the bomb was dropped: its purpose is to challenge the notion that nuclear weapons ended the Pacific War, suggesting that the bombs were never expected to end the conflict and that official statements claiming that the bombs had always been capable of doing so were generated after the war had ended. The source is valuable because it centres on alternative reasons for Japanese capitulation including the threat of Soviet entry to the war, an angle that the other Western sources used in this investigation did not suggest. Furthermore, Gordin's book is useful because it challenges the definition of whether or not the bomb "worked", writing that in the initial stages of war planning the bomb would be considered a success if it managed to detonate. The source mentions plans for further nuclear weapons, indicating that the Nagasaki attack was not anticipated to be decisive and therefore not militarily necessary.  However, it is limited in that it does not originate from Japan, which undermines the ability to take into consideration its political effect as well as that on morale in general.

Source B: The Decision to Use the Atomic Bomb by Henry Lewis Stimson
Written by Stimson in 1947, who was secretary of war at the time of the dropping of the bomb, this article was released in response to "[comment
s] about 
decision" to use atomic weapons in order to justify them. As a source released only two years after the end of the war, it is valuable because it is indicative of the mindframe of the U.S. government during this time: Stimson's account is crucial when considering the nuclear attacks because he led the project and his analysis details why the atomic bombs were used and how the project developed, providing insightful information on how the U.S. government wanted the bombing to be perceived as well as the psychological impact of the bomb on surrender. However, the source is limited in that it fails to acknowledge details pertaining to the Japanese perspective: although Stimson acknowledges intercepting telegrams, he emphasises the "Japanese
" over Japan's desire for a mediated peace. Furthermore, the article was published at the beginning of the Cold War and may have been influenced by the implementation of propaganda; Stimson's purpose to defend the bombing would be unlikely to outline any governmental mistakes.

Section D - Analysis (582)
    This investigation is important within its historic context because the nuclear attack on Nagasaki was part of first atomic campaign ever used in warfare. As the final bomb used prior to Japan's surrender, Nagasaki generated much controversy as to whether or not the use of nuclear weapons concluded the Pacific War. Due to his personal control over the project, Stimson's explanation of factors prompting the USA to detonate the bomb is crucial when judging its military necessity. Furthermore, his 1947 justification of the attacks would influence memoirs later published by Truman and subsequently affect how the bomb was perceived by the U.S. public. Gordin deromanticizes the bomb's legacy and describes how Nagasaki was never anticipated to end the war, undermining its necessity the as the USA readied itself for a "November invasion" of Kyushu.
    Stimson claims that Nagasaki was militarily necessary because it achieved the
intended" purpose of "[devastating] the Japanese homeland". Stimson cites the bomb's psychological impact as a means of achieving this: already crippled by blockades and military recession, "the 
 would shatter the obstinacy of the Japanese War Party. Furthermore, Stimson writes that an invasion could "cost
 casualties" and suggested that the bomb would conclude the war.
This estimate was echoed by Truman in his official memoirs - yet "military planners before Hiroshima had placed the number [between 20,000 and 46,000] American lives" . With each draft of Truman's book, these figures were progressively increased - "[the first draft estimating] a million... casualties with at least 300,000 dead..."- until set at 500,000 deaths upon its publication in 1955 . These discrepancies imply that the justification of the attacks was adapted to convincing the  West of their necessity.
    Nagasaki was not a military priority becaue Japan had long anticipated defeat. In February 1945, Prince Konoe declared this was "inevitable" and by July, Japan sought an opportunity to mediate for peace while maintaining sovereignty.  Despite intercepting telegrams detailing this wish, the U.S. did not initiate further negotiations, instead proceeding to plan nuclear attacks. Gordin stresses that atomic weapons were never considered to be decisive:  "after Hiroshima, 'work' meant shortening the war by a few months... only after 14 August did 'work' mean 'end the war'". While planning a third bomb, "the sudden surrender... caught Washington... off-guard" because the bombs were perceived as preparation for the scheduled invasion.
    Psychological warfare, although suggested by Stimson as an effective means to induce Japanese surrender, did not have a momentous impact: leaders found it "hard to differentiate" between firebombing and nuclear bombs, claiming Japan would "never surrender as a result of air raids". On the other hand, the Soviet declaration of war left Japan without a prospect of attaining favourable terms: it had lost a mediator and gained an enemy threatening to revive a multi-front war Japan could impossibly uphold. Emperor Hirohito urged the government to surrender as a result.
    The atomic bomb's "epochal" status can be attributed to the coincidence that it occurred parallel to the decisive Soviet entry. However, the Nagasaki attack did not impact any factors that would cause Japan to surrender and was instead regarded as a conventional bombing. Hiroshima had not induced surrender; there was no reason to believe Nagasaki - a target second to Kokura - would achieve this.

Section E - Conclusion (122 words)
    The 1945 attack on Nagasaki cannot be described as a military priority: while the use of a second nuclear weapon may have had a confirmatory impact on Japan's decision to accept unconditional surrender, it had long considered itself defeated. The U.S. decision to use the weapon was based on weakening Japan prior to an invasion rather than ending the war immediately. Despite its great destructive power, the Japanese response to the atomic bomb was similar to their regard of previous firebombing whereas the Soviet entry to the war brought about its strategic bankruptcy and eventual surrender. To conclude, neither the context nor the impact of the Nagasaki bomb justified its necessity and the idea that it was decisive is a post-war creation.

Section F - List of Sources

Asada, Sadao. "The Shock of the Atomic Bomb and Japan's Decision to Surrender: A     Reconsideration." The Pacific Historical Review 67.4 (1998): 477-512. University of     California Press, 16 Mar. 2009. Web. 12 Sept. 2012.

    "Atomic Bomb Records & Newspapers." Atomic Bomb Records. Archives.com, n.d. Web. 25 Mar.     2013. .

Bernstein, Barton J. "A Postwar Myth: 500,000 U.S. Lives Saved." Bulletin of the Atomic     Scientists June-July 1986: 38-39. Print.

Dionisi, David J. American Hiroshima : The Reasons Why and a Call to Strengthen America's     Democracy. Victoria, B.C.: Trafford, 2005. Print.

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

"The Manhattan Project -- Its Long-term Influences." DOE Research and Development (R&D)     Accomplishments. DOE Research and Development (R&D) Accomplishments, 15 Oct.     2012. Web. 03 Nov. 2012. .

Marshall Cavendish Corporation. World and Its Peoples: Eastern and Southern Asia. New York:     Marshall Cavendish, 2008. 1075. Print.

Mearsheimer, John J. The Tragedy of Great Power Politics. New York: Norton, 2001. Print.

Morris, Peter W. G. "The Manhattan Project." The Management of Projects. London: T. Telford,     1994. Print.

"Nagasaki." Institute for Structure and Nuclear Astrophysics, n.d. Web. 20 Sept. 2012.     .

"Proclamation Defining Terms for Japanese Surrender." Potsdam Declaration / Birth of the     Constitution in Japan. National Diet Library, n.d. Web. 23 Sept. 2012.     .

Stimson, Henry L. "The Decision to Use the Atomic Bomb." Harper’s Magazine Feb. 1947.      Columbia University. Web. 20 Sept. 2012.     .

Truman, Harry S., and Robert H. Ferrell. Off the Record: The Private Papers of Harry S. Truman.     New York: Harper & Row, 1980. Print.

Derry, J. A, and Ramsey, N. F. ."Memorandum for: Major General L.R. Groves. Subject: Summary     of Target Committee Meetings on 10 and 11 May 1945" The National Security Archive - The     George Washington University. The George Washington University. 12 May 1945. Web. 19     Sept. 2012.

Wilson, Ward. "The Winning Weapon? Rethinking Nuclear Weapons in Light of     Hiroshima."     International Security 31.4 (2007): 162-79. Print.

Yagami, Kazuo. "War and Its Aftermath." Konoe Fumimaro and the Failure of Peace in Japan:     1937-1941 : A Critical Appraisal of the Three-time Prime Minister. Jefferson, N.C. [u.a.:     McFarland, 2006. 141. Print.


Plan of Investigation:

During a press release by the Japanese government, Prime Minister Suzuki made a statement regarding the Potsdam Declaration, the United States terms for Japanese surrender, saying that with regards to the document the government of Japan would “mokusatsu-suru” it. This was translated to mean that the Japanese would ignore the ultimatum, unsurprising to some who had come to expect the suicidal “no-surrender” attitude from the Japanese. However, upon further reflection on the actual meaning of the word from a Japanese perspective and the actions taken by the Japanese to pursue peace since the beginning of 1945 this raises a question as to what had actually been meant by the word.  Did the Japanese intend to snub the Allies’ Potsdam Declaration by using the word “mokusatsu”?

I will examine what the meaning of the word mokusatsu actually means from a Japanese perspective as well as the context that the press conference was held in.  This will allow me to see if the statement was ever even meant to cross through diplomatic channels or whether it was only meant for the Japanese people. I will also examine the real reasons behind the Truman administration’s decision to deploy atomic weapons to see if the word actually had any influence on the decision or whether it was decided on from the start.
I will be using two primary sources: Alperovitz’s The Decision to use the Atomic Bomb and Torikai’s Voices of the Invisible Presence: Diplomatic Interpreters in Post-World War. Alperovits, has a special understanding of the intricacies of United States foreign policy and its history on account of his work in the State Department and US House of Representatives.  His book, which has been cited by over 70 similar books, details the rationales of the Truman administration to drop the bomb.  Being a veteran Japanese diplomatic interpreter, Torikai provides a crucial cultural knowledge of the word and it’s meaning within Japanese society and also on the difficulties and pitfalls of diplomatic interpretation she has knowledge of due to her experience. 

Summary of Evidence:

Before the US dropped the bomb on Hiroshima and Nagasaki in August 1945, Japan was effectively defeated and ready to capitulate . As early as January of that year, Japanese intermediaries were expressing an interest in agreeing on the Atlantic Charter’s terms of surrender, as it would allow them to keep the Imperial system intact .  Alperovitz writes that “there could no longer be any real doubt as to the Japanese intentions; the maneuvers were overt and explicit and, most of all, official acts1.”  Following the bombings, the Lord Privy Seal Koichi Kido, a close advisor to the Emperor, stated, “Our decision to seek a way out of this war, was made in early June before any atomic bomb had been dropped and Russia had not entered the war. It was already our decision .” 

    Formal diplomatic channels between the United States and Japan had been closely maintained by Foreign Minister Togo. However, on July 27, Japanese officials heard Captain EM Zacharias, acting official spokesman for the United States Army, issue a broadcast statement threatening Japan with virtual destruction unless there was “unconditional surrender with its attendant benefit as laid down by the Atlantic Charter”.    In addition, the broadcast contained a veiled threat that the Soviet Union would enter the war if Japan did not surrender quickly.  On one hand, the broadcast served as a way to give the war-weary Japanese people hope that the costly war would be coming to an end and despite their defeat, the Imperial dynasty would be preserved under the Atlantic Charter.  However, President Harry S. Truman and Secretary of State James Byrnes had altered the language of the Potsdam Treaty to read, “… eliminated for all time the authority and influence of those who have deceived and misled the people of Japan in embarking on world conquest”, which could be broadly interpreted as not only fingering the military as being responsible for the war but also the “God-Emperor who’s authority and influence had been used at every stage to lead the Japanese people into conquest .” 

    The change came as a shock to Japanese diplomats and was seen as a “counter blast” to their initiatives to find peace with the United States. In addition, the sudden change put a tremendous burden on Foreign Minister Togo who now needed more time to clarify what the change would mean for Japan and to investigate the possibility of a Soviet invasion.   Additionally, he had to satisfy the conflicting goals of the Emperor to find peace at all costs and the Japanese military heads who demanded an honorable surrender that retained the Imperial system, or at least the Emperor.   In an effort to buy time for the cabinet to clarify their position on the new treaty, Prime Minister Suzuki responded to an eager press with the word “mokusatsu” in a rushed press conference.  The foreign press translated the word to mean that the Japanese government was “ignoring” the declaration and were determined to fight to the end.  Truman, fearful of the growing Soviet threat and wary of an invasion to take over the country, authorized the use of atomic weapons. 

Evaluation of Sources:

    The book Voices of the Invisible Presence: Diplomatic Interpreters in Post-World War II Japan was published in 2009 and written by Kumiko Torikai.  The book analyzes the training and function of diplomatic interpreters in post-war Japan and their importance in translating the social, political, and economic aspects of the post-war years.  Pages 33 and 35, focusing on the Potsdam Declaration were of particular interest to this investigation as they focused specifically on how the word “mokusatsu” was interpreted and on how it was seen from a Japanese perspective verses a Western one. The author, Japanese women, is the Director of the English Language Program at Rikkyo University and has been a professor since 1997.  Torikai has over 30 years of experience as an interpreter and interviewer. However, Torikai is not a historian and does not have access to the archive. That being said, her expertise as a diplomatic interpreter who is Japanese fills a niche that is vital to this investigation.


The author of The Decision to Use the Atomic Bomb, Gar Alperovitz, is a political economist and president of the National Center for Economic Alternatives.  He also served as Senior Research Scientist in the Department of Government and Politics at the University of Maryland and is a Fellow of the Institute for Policy Studies. As a Fellow of King’s College, Cambridge, and the Institute of Politics at Harvard, he has served as Legislative Assistant in the U.S. House of Representatives, legislative Director in the U.S. Senate, and Special Assistant in the Department of State. 

    Having been published in 2010, The Decision to Use the Atomic Bomb offers a modern perspective of the events leading up to the decision to drop the bomb on Japan and takes a controversial stance asserting that the United States did not need to deploy atomic weapons to force Japan to surrender.  For the purposes of this investigation I found that the book contributed detailed accounts and insights of the events that led up to the Potsdam Conference and augmented my understanding of the sequence of events that led towards the two atomic bombings of Japan.  I decided to use this book because other historians often use Alperovitz as a reference. 

    However, in condemning the bombings the book fails to acknowledge key relevant topics such as the casualties sustained by Americans during the Pacific Campaign and the fighting resolve that the Japanese have demonstrated time and again, often willing to take their own lives than surrender.  The damage inflicted by the atomic bombs also lacks context by not including the damage inflicted in other areas of conflict such as Russia and Germany.  The book also treats the decision as a black and white affair and fails to take into account the fact that it was a complex decision contributed to by multiple people in a stressful and “fog of war” atmosphere. 


    It is difficult to determine whether Truman’s decision to drop the bomb stemmed from his uncertainty over Japanese surrender or from his fear of an aggressive Soviet Union. Torikai thinks that the perceived meaning of the word “mokusatsu” was instrumental in the decision and that Truman was led to believe that the Japanese were unwilling to surrender based on the language of their reply. 
The Allies were under “real pressure” at Potsdam to neutralize or marginalize the growing threat of the Soviet Union as well as end the war quickly.   This in turn put pressure on Japan to respond quickly and decisively to the Potsdam Declaration. Unfortunately, it was radically different than the Atlantic Charter that allowed the “right of all peoples to choose the form of government under which they will live”.  This new declaration included language that called for “eliminating for all time the authority and influence of those who have deceived and misled the people of Japan into embarking on world conquest”.13 Alperovitz writes that even those who had supported the Administrations position regarding the changes, like The New York Times, pointed out that the language of the changes was broad enough to include not just the military caste but also the Emperor of Japan as culprits in starting the war.  Kumiko Torikai argues that under pressure to buy time to adjust to sudden changes in the terms of surrender, the Prime Minister, 77-year-old Suzuki Kantaro, held a press conference and said:

My thinking is that the joint declaration is virtually the same as the Cairo Declaration. The government of Japan does not consider it having any crucial value. We simply mokusatsu-suru. The only alternative for us is to be determined to continue our fight till the end . 

The only semi-official Domei Press translated Suzuki’s comment into English as “the Japanese government ignores this, and we are determined to continue our fight in the war till the end”.15 U.S. and U.K. press then reported this statement as “Japan rejects Potsdam Declaration” and “Japan Officially Turns Down Allied Surrender Ultimatum”.   Consequently, Truman took this as another case of Japanese “death before dishonor” fanaticism and as evidence that the only way to end the war was to make the Japanese people face the threat of total annihilation.  However, it was clear that this was not the outcome that the Japanese government intended.  As early as January 1945 the Japanese had been sending out intermediaries to the Allies expressing their willingness to surrender under the terms of the Atlantic Charter.  

The statement issued by Suzuki was not meant to be interpreted as the Japanese government ignoring the peace treaty. The problem came from the translation of the word ‘mokusatsu” from Japanese to English.  Torikai takes from Ohno Susumu, professor emeritus of Gakushuin University to describe the word “mokusatsu” as a delicate phrase reflecting the mentality of the Japanese people in interpersonal communication.  The word is meant to mean pretending not to notice a mistake made by others so as to avoid downgrading yourself.19  In this case, the Japanese Prime minister meant to buy time for the cabinet to react to the likelihood of a Soviet invasion if they did not surrender and whether or not the new Potsdam Declaration edited by Truman and Byrnes could accuse the Emperor along with top generals of being prime instigators of the war by failing to mention the post war status of the Emperor in the Potsdam Declaration.   Interestingly, Hasegwa Saji of the Domei Press, who was allegedly responsible for translating the Prime Minister’s statement admitted unofficially in 1970 that he should have translated “mokusatsu” as “no comment” instead of “ignore” but admitted that he was not aware of the expression at the time.

It was never the intention of the Japanese government to spurn the Allies. They had exhaustedly tried to signal to them that they were willing to agree to the terms of the Atlantic Charter only to be taken completely by surprise when the new Potsdam Declaration was announced to the public, which called into doubt the immunity of the Emperor from being tried as a war criminal.  The shocked Japanese government was then forced to make a public announcement regarding the Declaration for the people as well as to by time in order for the government to figure out how to deal with the situation, resulting in the Prime Minster issuing a statement that was mistranslated and interpreted as yet another refusal of peace.  Alperovitz contends that the mistranslation did not effect Truman’s decision.  Torikai believes it played a role.  In hindsight, it seems as though the atomic bomb solution for Japan was not necessary for ending the war, especially since the Emperor system remained.

Alperovitz, G. (1995). The Decision to Use the Atomic Bomb. In G. Alperovitz, The Decision to Use the Atomic Bomb (p. Chapter 32). New York, NY: Random House.
Black, D. J. (2007). The Second World War, V.3: The Japanese War, 1941-1945. Ashgate.
Chappell, J. D. (1997). Before the Bomb: How America Approached the End of the Pacific War. University Press of Kentucky.
Gar Alperovitz. (n.d.). About Gar. Retrieved July 2013, from Gar Alperovitz: http://www.garalperovitz.com/about-gar/
Ham, P. (2012). Hiroshima Nagasaki . Random House.
Hellegers, D. M. (2002). We, the Japanese People: Washington. Stanford University Press.
Hoffmann, S.-L. (2011). Human Rights in the Twentieth Century . Cambridge University Press.
Institute for Historical Review. (1997, May-June). Was Hiroshima Necessary? Retrieved July 2013, from Institute for Historical Review: http://www.ihr.org/jhr/v16/v16n3p-4_Weber.html
Iriye, A. (2009). Power and Culture: The Japanese-American War, 1841-1945. Harvard University Press.
Nimmo, W. F. (2001). Stars and Stripes Across the Pacific: The United States, Japan, and Asia/Pacific Region, 1895-1945. Greenwood Publishing Group.
Torikai, K. (2009). Voices of the Invisible Presence: Diplomatic Interpreters in Post-World War. In K. Torikai, Voices of the Invisible Presence: Diplomatic Interpreters in Post-World War (pp. 33-38). John Benjamins Publishing Co.
Torikai, K. (2009). Voices of the Invisible Presence: Diplomatic Interpreters in Post-World War. Retrieved July 2013, from Google Books: http://books.google.com/books?id=I1nu69nmlxgC&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false