This post is a continuation of our series on the atomic bomb.

III. Leading Up to the Bomb

The Americans had captured Iwo Jima and Okinawa, with heavy casualties. They had destroyed most of the Japanese navy and almost all Japanese shipping. (The Japanese were very poor at both submarine and antisubmarine warfare. American subs sank Japanese ships virtually as they pleased.) American battleships were pounding coastal zones on Honshu and hundreds of B-29s had been hitting Japanese cities every day since February. A total of 260,000 people were killed in the March-August 1945 camapign of terror bombings against Japanese cities.

But the Japanese would not surrender.

The destruction continued relentlessly, at virtually no loss to the American bomber crews but at appalling cost to Japan; by July 60 percent of the ground area of the country's sixty largest cities and towns had been burnt out. As MacArthur and other military hardheads had argued, however, the devastation did not seem to deflect the Japanese government to continuing the war. In early April (1945), after failing to draw China into a separate peace, Koiso had been replaced as Prime Minister by a moderate figurehead, the seventy-eight-year-old Admiral Kantaro Suzuki; Tojo, though a deposed Prime Minister, nevertheless retained a veto over cabinet decisions through his standing in the army, and he and other militarists were determined to fight it out to the end. This determination exacted sacrifices which even Hitler had not demanded of the Germans in the closing months of the war. The food ration was reduced below the 1500 calories necessary to support life, and more than a million people were set to grubbing up pine roots from which a form of aviation fuel could be distilled. On the economic front, reported a cabinet committee instructed by Suzuki to examine the situation, the steel and chemical industries were on the point of collapse, only a million tons of shipping remained afloat, insufficient to sustain movement between the home islands, and the railroad system would shortly cease to function. Still no one dared speak of peace. Tentative openings made in May through the Japanese legation in Switzerland by the American representative, Allen Dulles, were met with silence: over 400 people were arrested in Japan during 1945 on the mere suspicion of favoring negotiations.

In midsummer the American government began both to lose patience at Japan's intransigence and to yield to the temptation to end the war in a unique, spectacular, and incontestably decisive way. They were aware through Magic intercepts that the Suzuki government, like Koiso's before it, was pursuing backdoor negotiations with the Russians, whom it hoped would act as mediators; they were also aware that a principal sticking-point in Japan's attitude to ending the war was the "unconditional surrender" pronouncement of 1943, which all loyal Japanese recognized as a threat to the imperial system. However, since the Russians mediated in no way at all, and since the Potsdam conference following the surrender of Germany indicated that uncinditional surrender need not extend to the emperor's deposition, America's willingness to wait attenuated during the summer. On 26 July the Potsdam Proclamation was broadcast to Japan, threatening "the utter destruction of the Japanese homeland" unless the imperial government offered its unconditional surrender. Since 16 July President Truman had known that "utter destruction" lay within the United States's power, for on that day the first atomic weapon had been successfully detonated at Alamogordo in the New Mexico desert. On 21 July, while the Potsdam meeting was in progress, he and Churchill agreed in principle that it should be used. On 25 July he informed Stalin that America had "a new weapon of unusually destructive force". Next day the order was issued to General Karl Spaatz, the commander of the Strategic Air Forces, to "deliver its first special bomb as soon as weather will permit visual bombing after about 3 August 1945 on one of the targets: Hiroshima, Kokura, Niigata, and Nagasaki". The attempt to bring the Second World War to an end by the use of a revolutionary super-weapon had been decided.

Source: The Second World War, John Keegan.