In the months and years after the atomic bombs were dropped on Japan in August 1945, those in some way involved in the decision offered a variety of reasons for their actions. Let us begin this pivotal chapter with statements from four such people. We can start with Robert R. Wilson, the young Princeton physicist who came to Los Alamos in 1943 imagining himself as Hans Castorp arriving at Thomas Mann’s Magic Mountain. Why test, then drop the bomb? Wilson’s reminiscence here came nearly a quarter century after the Pacific War had ended:
Perhaps events were moving just too incredibly fast. We were all at the climax of the project—just on the verge of exploding the test bomb in the desert. Every faculty, every thought, every effort was directed toward making that a success. I think that to have asked us to pull back at that moment would have been as unrealistic and unfair as it would be to ask a pugilist to sense intellectually the exact moment his opponent has weakened to the point where eventually he will lose, and then to have the responsibility of stopping the fight just at that point.
There was momentum behind the scientists’ decision to build the bomb. The momentum carried through construction of the test gadget, the test itself, and the decision to use the bomb against an opponent—or such is the implication of Wilson’s analogy. Once under way, the Manhattan Project became a means that required an end, a force of logic that could be satisfied only by resolution in the cause of battle—that is, against people.1
The second statement comes from a more familiar source: Harry S. Truman, who became President of the United States following Franklin Roosevelt’s death on 12 April 1945 and was in office when the bombs were dropped and the war against Japan ended. More than anyone, Truman made the decision to use atomic bombs, though a search for a particular document or statement by Truman actually authorizing the bombings is curiously unfulfilling. In any case, it was to his president that Samuel McCrea Cavert, the general secretary of the Federal Council of Churches of Christ in America, wrote on 9 August, just after the second atomic bomb had been dropped on Nagasaki. Many Christians, Cavert wrote, were ‘deeply disturbed over [the] use of atomic bombs against Japanese cities’; the weapons were ‘indiscriminate’ and set an ‘extremely dangerous precedent’. Truman replied tersely on the 11th. ‘My dear Mr Cavert,’ he began:
Nobody is more disturbed over the use of Atomic bombs than I am but I was frankly disturbed over the unwarranted attack by the Japanese on Pearl Harbor and their murder of our prisoners of war. The only language they seem to understand is the one we have been using to bombard them.
When you have to deal with a beast you have to treat him as a beast. It is most regrettable but nevertheless true.
Vengeance, then, was part of Truman’s motive: the Japanese had attacked first, and treacherously, and had mistreated American prisoners. Evidently, too, the Japanese were impervious to reason, understanding only force, war’s lingua franca. And, most memorably, there is Truman’s description of the Japanese as ‘a beast’, vicious, violent, less than human. Atomic bombs were necessary, according to this logic, and they were legitimate, because no one cared that or how a beast was exterminated, least of all the beast.2
Statement three comes from Truman’s successor as President, Dwight D. Eisenhower. It is actually two comments, combined as many other historians have combined them, but in fact recorded in two different places. In 1945 Eisenhower was commander of Allied Forces in Europe, and in this role he attended the conference at Potsdam, where the Big Three—Truman, Joseph Stalin, and (temporarily, as it turned out) Winston Churchill—discussed the fate of Central and Eastern Europe and the endgame of the war against Japan. In the first volume of his memoirs, published eighteen years later—that is, after his presidency—Eisenhower recounted that Secretary of War Henry Stimson had told him at Potsdam that the atomic bomb would be dropped on Japan. The general recalled his reaction:
I voiced to him my grave misgivings, first on the basis of my belief that Japan was already defeated and that dropping the bomb was completely unnecessary, and secondly because I thought that our country should avoid shocking world opinion by the use of a weapon whose employment was, I thought, no longer mandatory as a measure to save American lives. It was my belief that Japan was, at that very moment, seeking some way to surrender with a minimum loss of ‘face’.
Then, the quotable coda, which appeared not in the memoirs but in Newsweek in November 1963: ‘It wasn’t necessary to hit them with that awful thing.’3
The passages suggest, in the first place, the possibility that a leading American general distinguished between the use of a nuclear weapon and other forms of warfare, judging the first ‘unnecessary’ and ‘awful’, more awful at least than other weapons already being used. More significantly, it suggests that there may have been reasons other than the quest for swift and sure victory why Truman decided to use bomb(s) anyway. Surely Stimson would have taken seriously the military judgment of his general (Japan was looking to surrender); surely he would have accepted Eisenhower’s logic that the atomic bomb was not necessary to win the war. That he apparently did neither of these things—that he did not refrain from recommending use of the bomb—must therefore mean that Stimson had other reasons to want his president to use it. Revisionist historians, indeed, have found in the Eisenhower quotations evidence that, for Stimson, Secretary of State James Byrnes, and Truman, the real target of the atomic bomb—Japan being, as Eisenhower said, all but defeated without it—was the Soviet Union. If atomic bombs were dropped on Japan, the war would end more quickly, depriving the Soviets of much involvement in the war’s endgame and thus of a prominent place in the postwar occupation authority in Japan. And if the United States dropped atomic bombs, the Soviet leadership might be intimidated by American power and become more agreeable in negotiations on the political future of Germany and Eastern Europe, already a matter of friction between the Allies.4
One more statement, this from Stimson himself. Henry Stimson, who was 77 years old in 1945, was a dedicated public servant who played a critical role in the drama of the atomic bomb. It was he who told Truman, hours after Truman became President, of the existence of ‘a new explosive of almost unbelievable destructive power’ then under development, who chaired the secret Interim Committee that advised the President about how to use the bomb, and who removed the city of Kyoto from the bombs’ target list, overriding the objections of Leslie Groves. By early 1947, as the Cold War intensified, there were rumblings in US policy circles and in the American press that the bombs had been aimed primarily at the Soviets, not the Japanese, and had thus been militarily unnecessary. Stimson responded, in the February issue of Harper’s magazine, with ‘The Decision to Use the Atomic Weapon’, a piece meant to disarm critics by revealing the inside version of official deliberation in the months leading up to the bombing of Hiroshima. Why, then, did the United States drop the bomb?
My chief purpose [Stimson wrote] was to end the war in victory with the least cost in the lives of the men in the armies which I had helped to raise. In the light of the alternatives which, on a fair estimate, were open to us I believe that no man, in our position and subject to our responsibilities, holding in his hands a weapon of such possibilities for accomplishing this purpose and saving those lives, could have failed to use it and afterwards looked his countrymen in the face.
The bomb, according to Stimson, was not used for some nefarious or secret reason, but because it promised to end the war sooner and thus save lives. It was American lives that Stimson cherished and mentioned in the passage, but in his following paragraph he noted that, by ending the war, the atomic bombs ended the firebombing of Japanese cities and the blockade of Japan by US ships and thus saved Japanese lives too. The atomic bomb was justified as the most humane way to prosecute, then terminate, the atrocious war.5
It will be noted that all four of these statements were made after the bombs had been dropped: Truman’s within a couple of days, Stimson’s over a year later, Eisenhower’s nearly two decades and Wilson’s a quarter of a century afterwards. Perhaps Truman had not had much time to think before sending a response to Samuel Cavert, but the others had had plenty of time, and were surely conscious that they were setting down their positions for posterity on a subject fraught with controversy. During the war itself, in the heat of battle, most scientists, generals, and statesmen had neither the time nor the inclination to ask themselves whether the atomic bombs should be used. The modifier ‘most’ is essential here, since, as we will see, there were those (not Eisenhower) who urged at the time that the bombs not be dropped, that an alternative be found to end the war that did not involve using nuclear weapons against undefended cities. These arguments were either ignored or considered and rejected. The context in which they were made was that of total war against an enemy widely regarded as ruthless and disinclined to surrender unless utterly defeated. Franklin Roosevelt had insisted early in 1943 that Germany, Italy, and Japan surrender without condition; not only the capacity of the Axis nations to make war but their ideological tendency to do so must be expunged. Harry Truman accepted the demand for unconditional surrender as part of his predecessor’s legacy. Defeat alone was insufficient; the enemy must be destroyed. Atomic bombs would facilitate his destruction.
The Manhattan Project began because of fears that Nazi Germany would move rapidly to build an atomic bomb, and that a bomb in Nazi keeping would mean catastrophe for the civilized world. When President Roosevelt had agreed, on 9 October 1941, to move ahead with developing an atomic bomb, Germany and its allies had established control over much of Europe, had substantial forces in North Africa that appeared to threaten also the Middle East, had waged war from the air against Great Britain (with serious psychological though without decisive strategic results), and, the preceding June, had broken the Molotov-Ribbentrop Pact of 1939 and invaded the Soviet Union, with frightening success to that point. The United States and Germany were not yet at war, but their relations were icy and their ships were firing at each other in the North Atlantic, as American vessels carried supplies and munitions to Britain and the Soviet Union and provided cover against German submarines for their own ships and others. War came, by German declaration, two months later. Through 1942, as the Americans improved the coordination and tightened the secrecy of their bomb effort, as Ernest Lawrence began producing minute amounts of uranium 235 in his Berkeley Calutrons and Enrico Fermi built his atomic pile in a University of Chicago squash court under the aegis of Arthur Compton’s energized Met Lab, and as Leslie Groves went from colonel to general as he took vociferous command of what was now the Manhattan Project, the German grip on power started gradually to loosen. The Battle of Britain went the way of the Royal Air Force; the invasion of the Soviet Union sputtered, then stalled. The German atomic bomb project was frustrated by decentralization, scientific missteps, and lack of sympathy at the political top, though the Allies did not know this. In the summer of 1942 the first American bombs struck targets in occupied Europe. The Battle of the Atlantic turned in the Allies’ favor. In November, while workers in Chicago skidded on residue from Fermi’s graphite and Groves and Robert Oppenheimer sealed their functional courtship by agreeing to build the bomb at Los Alamos, American and British troops were landing in North Africa (Operation Torch) to begin the destruction of the Nazi empire from the outside in. Winston Churchill called the strategy ‘closing the ring’.
As the scientists moved to Los Alamos in the spring of 1943 and construction progressed at the massive plants at Oak Ridge and Hanford, German military reverses multiplied. The invasion of North Africa bore fruit that May, when Allied forces defeated the German Afrika Corps and took a quarter of a million prisoners. The tide turned in the Atlantic that spring too, as the Americans and Canadians built supply ships more quickly than German U-boats could sink them and improvements in Allied sub detection and defense took hold. In April the Germans lost fifteen subs to Allied attack; in May the figure was forty, and their commander, Karl Donitz, was forced to pull them back. The Allies, who had lost over 1,800 ships to the Germans in 1942, would sacrifice barely 800 in 1943. The Germans surrendered at Stalingrad on 2 February, prompting propaganda minister Joseph Goebbels to admit publicly the growing seriousness of the German military position and to exhort his audience to greater efforts. The Soviets marshaled a counteroffensive. That summer the British and the Americans attacked Sicily, and Allied troops set foot in Italy in early September, prompting a near-immediate Italian surrender.
The Germans fought on, in Italy and Eastern and Western Europe. As the Manhattan Project scientists, along with Groves, confronted problems—not enough atomic fuel, puzzles concerning bomb size and implosion and how best to trigger the weapon—Allied troops continued to tighten the circle. Rome was finally captured on 5 June 1944. The Russians liberated Romania, Bulgaria, Yugoslavia, Poland, and Hungary through the year and into 1945. Stalin had chafed while awaiting a British-American assault across the English Channel; D-Day came finally on 6 June, and France was restored in August. Everywhere, German armies were falling back and ordinary Germans were dying. And yet there might still be surprises, as in the German counterattack at the Battle of the Bulge in December 1944. That the Germans were not close to having an atomic bomb was established with certainty by Alsos only in the spring of 1945— indeed, the Germans had started building a new atomic pile in Haigerloch that February. Until they were sure that Hitler was dead and Germany defeated, those working on the American bomb felt they could not afford to let up, and they did not.