The Biggest Decision: Why We Had To Drop The Atomic Bomb


Nor was that all. Regardless of the emperor’s actual role in Japanese aggression, which is still debated, much wartime propaganda had encouraged Americans to regard Hirohito as no less a war criminal than Adolf Hitler or Benito Mussolini. Although Truman said on several occasions that he had no objection to retaining the emperor, he understandably refused to make the first move. The ultimatum he issued from Potsdam on July 26 did not refer specifically to the emperorship. All it said was that occupation forces would be removed after “a peaceful and responsible” government had been established according to the “freely expressed will of the Japanese people.” When the Japanese rejected the ultimatum rather than at last inquire whether they might retain the emperor, Truman permitted the plans for using the bombs to go forward.

Reliance on MAGIC intercepts and the “peace feelers” to gauge how near Japan was to surrender is misleading in any case. The army, not the Foreign Office, controlled the situation. Intercepts of Japanese military communications, designated ULTRA , provided no reason to believe the army was even considering surrender. Japanese Imperial Headquarters had correctly guessed that the next operation after Okinawa would be Kyushu and was making every effort to bolster its defenses there.

General Marshall reported on July 24 that there were “approximately 500,000 troops in Kyushu” and that more were on the way. ULTRA identified new units arriving almost daily. MacArthur’s G-2 reported on July 29 that “this threatening development, if not checked, may grow to a point where we attack on a ratio of one (1) to one (1) which is not the recipe for victory.” By the time the first atomic bomb fell, ULTRA indicated that there were 560,000 troops in southern Kyushu (the actual figure was closer to 900,000), and projections for November 1 placed the number at 680,000. A report, for medical purposes, of July 31 estimated that total battle and non-battle casualties might run as high as 394,859 for the Kyushu operation alone . This figure did not include those men expected to be killed outright, for obviously they would require no medical attention. Marshall regarded Japanese defenses as so formidable that even after Hiroshima he asked MacArthur to consider alternate landing sites and began contemplating the use of atomic bombs as tactical weapons to support the invasion.

The thirty-day casualty projection of 31,000 Marshall had given Truman at the June 18 strategy meeting had become meaningless. It had been based on the assumption that the Japanese had about 350,000 defenders in Kyushu and that naval and air interdiction would preclude significant reinforcement. But the Japanese buildup since that time meant that the defenders would have nearly twice the number of troops available by “X-day” than earlier assumed. The assertion that apprehensions about casualties are insufficient to explain Truman’s use of the bombs, therefore, cannot be taken seriously. On the contrary, as Winston Churchill wrote after a conversation with him at Potsdam, Truman was tormented by “the terrible responsibilities that rested upon him in regard to the unlimited effusions of American blood.”

Some historians have argued that while the first bomb might have been required to achieve Japanese surrender, dropping the second constituted a needless barbarism. The record shows otherwise. American officials believed more than one bomb would be necessary because they assumed Japanese hard-liners would minimize the first explosion or attempt to explain it away as some sort of natural catastrophe, precisely what they did. The Japanese minister of war, for instance, at first refused even to admit that the Hiroshima bomb was atomic. A few hours after Nagasaki he told the cabinet that “the Americans appeared to have one hundred atomic bombs . . . they could drop three per day. The next target might well be Tokyo.”

Even after both bombs had fallen and Russia entered the war, Japanese militants insisted on such lenient peace terms that moderates knew there was no sense even transmitting them to the United States. Hirohito had to intervene personally on two occasions during the next few days to induce hardliners to abandon their conditions and to accept the American stipulation that the emperor’s authority “shall be subject to the Supreme Commander of the Allied Powers.” That the militarists would have accepted such a settlement before the bombs is farfetched, to say the least.