For two decades after the dropping of atomic bombs on the Japanese cities of Hiroshima and Nagasaki in 1945 most historians accepted the US government’s justification of its decision to use these weapons: that given the unwillingness of the Japanese government to seriously consider unconditional surrender, the bombings brought the war to a speedy end by allowing the US to avoid a conventional invasion of the Japanese mainland that would have cost hundreds of thousands of American (and Japanese) lives. (See Harry S. Truman’s post-war justifications for this position in the documentary section).
In the 1960s, however, some revisionist historians challenged these claims, arguing that the US decision to use these bombs had little to do with ending the Pacific War. Writing in the context of a broader debate on responsibility for the Cold War, these historians argued that Japan was effectively defeated by mid 1945 but that the US wanted to use its destructive new weapon to intimidate the Soviet Union (especially in Europe) and to end the Pacific War before the Russians became too heavily involved in East Asia. The most prominent advocate of this view was Gar Alperovitz, Atomic Diplomacy: Hiroshima and Potsdam (New York, 1965).
In the mid-1990s the debate over the dropping of the atomic bombs – until this time confined largely to historians – became the focus of public controversy. In 1995 the Smithsonian Air and Space Museum in Washington DC staged an exhibition to mark the fiftieth anniversary of the ending of the Pacific War. The exhibition included the restored forward fuselage of the Enola Gay, a photographic exhibition, and commentary on the bombings. It included discussion of the reasons for the bombing of the Japanese cities, photographs of the Japanese victims of the bombs, and a commentary on the nuclear arms race in the subsequent Cold War era. Various veteran organisations, backed by the US Senate, strongly objected to the format. It was condemned for a lack of patriotism, a lack of respect for US war veterans, and an overly sympathetic view of the Japanese position. In the end the Smithsonian backed down and made major modifications to the exhibition, including dropping references to the subsequent arms race and many pictures of the Japanese victims. The issue sparked a debate over political interference in the re-telling of history and also revived the atomic bomb controversy among historians. The scholarly debate now had the advantage of the large amount of US archival evidence declassified after the 1960s. See Edward T.Linenthal and Tom Engelhardt (eds), History Wars: The Enola Gay and Other Battles for the American Past (New York, 1996); and Robert P. Newman, Enola Gay and the Court of History (New York, 2004).
Despite the release of official documents from the 1970s, the broad outlines of the debate between traditionalist and revisionist historians remained unchanged. The revisionists took issue with traditional views in three main areas. They claimed that the US had ignored the fact that by July 1945 Japan was ready to surrender provided some arrangement could be made for the future of the Emperor Hirohito. Traditional historians continued to argue that the Japanese were divided on the surrender issue and that there was every indication that the war would go on. It was also claimed by the revisionists that the Truman administration delayed Russian involvement in the war and then ignored the significance of the entry of the Soviet Union into the war - which in itself would have been enough to bring about a Japanese surrender. The traditionalists countered that the US supported Russian entry as early as possible and that there was no indication that the attacks by the Red Army on the Japanese positions on the Asian mainland would have allowed the US to avoid an invasion of the Japanese islands. Finally, the two sides argued over whether Truman and others later inflated the estimated number of American casualties in a conventional invasion of Japan, in order to make the use of the atomic bombs seem a palatable alternative. On this second wave of the revisionist attack see Gar Alperovitz, The Decision to Use the Atomic Bomb andthe Architecture of an American Myth (New York, 1995); and Kai Bird and Lawrence Lifschultz (eds.) Hiroshima’s Shadow: Writings on the Denial of History and the Smithsonian Controversy (Stony Creek CT, 1998) Dennis D. Wainstock, The Decision toDrop the Atomic Bomb (Westport CT, 1996). The traditional responses can be found in books such as Robert James Maddox, Weapons for Victory: The Hiroshima Decision Fifty Years Later (Columbia, MO, 1995); and Robert P. Newman, Truman and theHiroshima Cult (East Lansing MI, 1995).
We should also note that other historians added a racial motive for the bombings. John Dower argued that the US waged a racial war in the Pacific against people it considered sub-human. This made use of the atomic bombs justifiable whereas, Dower argued, such weapons would never have been dropped on Germany during the European War. Ronald Takaki in particular cited the racist attitudes held towards the Japanese by Truman, claiming that such attitudes made the decision to use the atomic bombs so much easier. See John Dower, War without Mercy: Race and Power in the Pacific War (New York, 1986); and Ronald Takaki, Hiroshima: Why America Dropped the Atomic Bomb (Boston, 1995).
The last ten years have seen some attempt, in various ways, to deal with what had clearly become a rather polarised debate. These works are dealt with by J. Samuel Walker in a recent essay in Diplomatic History, although he tends to ignore aspects of the racial issue. Walker rightly cites his own work plus that of other historians, including those who have worked more fully in the Japanese archives, engaged in studies of the Emperor Hirohito, and looked at the broad sweep of the Pacific War. See Samuel J. Walker ‘Recent Literature on Truman’s Atomic Bomb Decision: A Search for Middle Ground’ Diplomatic History, Vol. 29, No 2, April 2005, pp. 311-334; Samuel J. Walker, Prompt and Utter Destruction: Truman and the Use of Atomic Bombs against Japan (Chapel Hill, NC, 1997); Richard B Frank, Downfall: The End of the Imperial Japanese Empire (New York, 1999); Sadoa Asada. ‘The Shock of the Atomic Bomb and Japan’s Decision to Surrender- A Reconsideration’ Pacific Historical Review, 67 November 1998, pp 477- 512; Herbert P. Bix, Hirohito and the Making of ModernJapan (New York, 2000); and Tsuyoshi Hasegawa, Racing the Enemy: Stalin, Truman andthe Surrender of Japan (Cambridge, MA, 2005)
On the issue of Japanese surrender, various studies suggest that in July 1945 the government had not decided to surrender and that Hirohito and the militarists had not been prepared to reach such a decision until the entry of the Russians into the war and the dropping of the atomic bombs finally forced the Emperor’s hand. In that sense the traditional view is supported. However, Hasegawa does suggest that the entry of the Russians into the war ended Japanese hopes that the USSR might act as intermediaries with the Americans and may have been even more important than the bombs in the decision to surrender. This at least gives some credence to the revisionist claims that Japan would have surrendered before a US invasion if the bombs had not been dropped. However, there is some danger of hindsight in such a view. Many militants wanted to continue fighting even after Russian entry and after the two bombs had been dropped; they were willing to surrender only because of the Emperor’s orders. Moreover, Truman could not be certain of Japanese intentions. Evidence that the Americans hoped or suspected that Soviet entry might be enough to end the war does not demonstrate that Truman knew that the atomic bombs would not be needed.
On the issue of simply using the bombs in order to head off the Russians in Asia and intimidate them in Europe, the findings suggest that the traditionalists are generally closer to the mark. Truman and his generals first and foremost pursued the war against Japan, and the atomic bombs were an important part of their strategy for ending the war. This, however, is not to say that they were not aware of the race with the Russians or the advantages of being able to demonstrate the destructive power of the new super bomb. Yet such a view has not been disputed by most recent traditional historians, who have seen Truman as a practical statesman with one eye on the post-war world and already dealing with problems with Stalin over Eastern Europe. He and his administration clearly saw advantages in possessing and even using the new bombs, but the issue was what primarily motivated them to do so in August 1945.
On the US casualty issue, the traditional view that the US would have suffered hundreds of thousands of casualties in an invasion of the Japanese mainland has not been supported by these studies. Again, however, the problem of hindsight is important. Truman and his advisers did not know how many American casualties would result from such an invasion, and it is perhaps understandable that they erred on the side of pessimism. Moreover, even the revised estimates presented in recent studies suggest that the human costs of an invasion would have been large. Frank suggests that even on his estimates of over 150,000 US casualties (including 35,000 dead) plus the massive Japanese losses, the atomic bombs would have represented the lesser of two evils and been the more attractive solution for Truman in ending the war. In this sense the traditional interpretation is closer to the truth, even though it exaggerates the likely casualty rate.
On the racial issues, it is true that stereotyping of the Japanese as sub-human was a significant part of US war propaganda. The perceived Japanese treachery at Pearl Harbor also made it easy to justify American revenge bombings on Japanese cities. On the other hand, the massive destruction of German cities throughout the war, including the fire-bombing of Dresden as late as February 1945, showed little in the way of US restraint when dealing with a European enemy. Indeed, the atomic bomb was developed primarily with a view to its use against Nazi Germany; and the weight of evidence suggests that had it not been for Germany’s surrender in May 1945, before development of the atomic bomb had been completed, a German city rather than Hiroshima would have been the first nuclear target. US wartime strategy was to use all means to bring the European and Pacific conflicts to an end as quickly as possible and to minimise American combat casualties. Whether it was correct or not, US military planners during the war had placed a great deal of faith in the use of massive air power to destroy an enemy’s military capacity and will to fight. The US government had always regarded the atomic bomb, from the beginning of its development, as a legitimate weapon of war. It was essentially just a more terrifying type of super bomb to be dropped in the same way as any of the conventional bombs of the war. Truman’s decision to drop the atomic bombs on Japan in order to quickly finish the war fitted in with these American military strategies that had little to do, ultimately, with racial attitudes irrespective of the personal beliefs of the President or for that matter Americans in general. However, provided we keep in mind US military thinking, perhaps racism did make the decision to use the bombs easier even if it was not an overriding factor and we also acknowledge they certainly would have been used against Germany if they had been ready in time.
Overall, the recent studies, have, in various ways, modified but not displaced the traditional views on why the bombs were dropped. Much of the revisionist case is based on the ahistorical assumption that Truman and US policymakers understood Japanese intentions with the same clarity as historians have been able to achieve decades after the event. In any case, the Japanese showed no serious signs of being willing to surrender in July and early August 1945, and the US government was faced with a possible conventional invasion of Japan which would have involved substantial casualties - if not quite the rates earlier figures had suggested. The bomb had been developed in accordance with US military strategies to win both the European and Pacific war as quickly and cheaply as possible and had the bonus of heading off Soviet influences in Asia. The war propaganda that depicted the Japanese as treacherous and sub-human reflected an American racism that may have made such a decision a little easier for Truman.