Why Did the Truman Administration Decide to Drop the Atomic Bombs on Japan in 1945?

On the month of August 1945, President Harry Truman administered the drop of two atomic bombs on Hiroshima and Nagasaki, Japan, which killed an estimated 150,000 people. Why he did this has been a huge focus of historical debate and will be the focus of this essay. The main claims are deliberated amongst two historical groups. Traditionalists felt it was a means to bring a swift end to the war as “the longer [it]… lasted, the more Americans [would be] killed”. Revisionists oppose this and argue that Truman actually used the atomic bomb as a diplomatic tool to intimidate the Soviet Union. As significant as these arguments are though, there are many other valid reasons that contributed to Truman’s decision. His predecessor, Franklin Roosevelt, launched the Manhattan Project in 1940, a top-secret program in which scientists and technicians carried out research on how to build the atomic bomb. Thus Truman may well have been just carrying on Roosevelt’s desire to use it. Finally, on top of this historians have argued that Truman felt that dropping the atomic bomb was an act of revenge against Japan for bombing Pearl Harbor during the war. The chief motivation for the Truman administration to drop the bombs however was to prevent Soviet influence from spreading even further like it had done in Europe by this time. This fear eventually culminated into the Cold War.

The main reason as to why the Truman administration dropped the atomic bombs was to intimidate the Soviet Union. Alperovitz strongly argues this case. He argues that the atomic bomb was a diplomatic tool in which Truman aimed to “limit Soviet political influence in Asia”. Simply, Truman wanted to drop the bomb before Soviet leader, Stalin, entered the war with Japan as he was aware of the expanding influence he was exerting in Europe, fearful that this would occur in the Far East too. There is strong evidence that validates this. In July 1945, Truman delayed the Potsdam meeting in which himself, Stalin and British Prime Minister, Churchill would discuss how to deal with the aftermath of the war. This suggests that he was buying his time, allowing a successful test of the atomic bomb to be carried out in secret which did in fact occur. This enabled Truman to order the drop of the bomb in the days before the Soviet Union was meant to invade Japan in August. Secretary of State, James Byrnes justified this himself, “we wanted to get through with the Japanese phase of the war before Russia got involved”. Another assertion that Alperovitz makes is that “Japan was defeated and preparing to surrender before the atomic bomb was used”. Robert Butow emphasizes that Japan’s decision to surrender “had long been taking shape” due to the large-scale B-29 bombing raids carried out by America in which after one night in Tokyo, 100,000 civilians died. This was confirmed by American air force General Curtis LeMay who boasted that Japan was being driven “back to the stone age”. Therefore, it is clear that Truman was primarily concerned with demonstrating America’s military might out of fear of Soviet influence spreading in the Far East.

Alternatively, this argument can be disputed by the fact that Truman dropped the atomic bombs to prevent further deaths of Americans and the Japanese and to bring a swift end to the war. Truman stated this in a personal letter on 9th August 1945, “my object is to save as many American lives as possible” whilst also emphasizing his “humane feeling” towards Japanese civilians. Historian, Herbert Feis adopts this argument as well. He feels that the use of the atomic bomb was solely a “military” decision – to “end the war victoriously as soon as possible”. This is supported further by the fact that the ongoing relentless war had come at a huge cost for both countries. In February 1945, America had lost more than 20,000 casualties during the invasion of Iwo Jima. Additionally, during the battle for Okinawa from April-June 1945, America incurred a further 50,000 casualties whilst Japan lost more than 100,000. This shows the dropping of the atomic bomb was a moral decision, to preserve life and put an end to future invasions which would cause the number of fatalities to rise. Contemporaries of the time challenge Alperovitz’ argument as they felt that Japan’s refusal to surrender led the Truman administration to use the atomic bomb to bring the war to a swift end. Secretary of War, Henry Stimson, announced in February 1947 that using the atomic bomb was necessary militarily as despite the huge loss of life in battles like the ones mentioned above, Japan was still committed to a total war and continued to deploy huge numbers of soldiers. Thus Stimson believed that a “tremendous shock”- the atomic bomb - had to be administered to gain a surrender and ultimately an end to the war. However, this is not a persuasive argument. As seen before, Truman did not drop the bomb for the goal of achieving a surrender as he and his administration were aware that Japan was defeated in the war already. The atomic bomb was merely a catalyst, finalizing Japan’s decision to surrender once and for all. Thus putting an end to the war was not the main reason for the dropping of the atomic bomb.

The claim that the use of the atomic bombs was revenge against Japan for its cruel war atrocities is also a valid one in terms of examining Truman’s reasoning behind dropping it in 1945. It has been argued that the bombing of Pearl Harbor in particular could have “generated the momentum for dropping the atomic bombs”. Truman was deeply disturbed over this attack as it was unexpected and unjustified, during peacetime. Over 2,000 civilians were killed and more than nineteen ships were sunk or disabled. Therefore, this prompted a motive of retribution for Truman and his administration, which can evidently be seen in a statement