Diana Preston - Before the Fallout

Heisenberg was taken to Heidelberg to be interrogated by Sam Goudsmit. Face-to-face with his old friend after six years, Goudsmit’s overwhelming impression was that Heisenberg was “actively anti-Nazi but strongly nationalistic.” Heisenberg was openly curious about Allied progress on fission and asked Goudsmit whether there was any program in the United States like the Germans’. Goudsmit implied there was not, prompting Heisenberg’s cheerful suggestion that “if American colleagues wish to learn about the uranium problem I shall be glad to show them the results of our researches if they come to my laboratory.” The German’s misplaced and bumptious confidence struck Goudsmit as pathetic.

Goudsmit’s last major target, Paul Harteck, was arrested in Hamburg, bringing the total that Goudsmit considered worth keeping in special detention to ten: Heisenberg, Diebner, Gerlach, von Weizsacker, Hahn, von Laue, Wirtz, Bagge, Korsching, and Harteck. On 3 July they were flown by Dakota to England for internment at Farm Hall, the elegant country house in Cambridge where, in 1942–43, Norwegian commandos had trained for their seemingly suicidal attack on the heavy water factory at Vemork.

At the beginning of August 1945 Sam Goudsmit was surprised to be recalled suddenly from Berlin, where relations with the Russians were already tense, to the safety of the U.S. military headquarters in Frankfurt. A few days later he would understand why.

ON 12 APRIL 1945 President Roosevelt, age sixty-three, died from a cerebral hemorrhage that had struck reputedly while he was 1 in bed with his mistress. Among his papers was found a draft of a % speech in progress, containing the following sentence: “More than an end to war, we want an end to the beginning of all wars—yes, an end to this brutal, inhuman and thoroughly impractical method of settling the differences between governments.” His successor, the sixty-year-old Harry S. Truman, scarcely knew of the Manhattan Project and its war-winning potential. However, within the first twenty-four hours of his presidency, he was briefed by Secretary of War Henry Stimson, who told him of “the development of a new explosive of almost unbelievable destructive power,” which was “so powerful as to be potentially capable of wiping out entire cities and killing people on an unprecedented scale.” James Byrnes, an adviser to Roosevelt and soon to be designated by Truman as his secretary of state, replacing Edward Stettinius, told him the bomb might well put the United States in a position to dictate its own terms at the end of the war.

In this and other briefings, the new president does not seem to have queried the underlying assumption that, when available, the bomb should be used and that the key questions were how and where. At the end of April German capitulation was clearly only a short while away (VE day was 8 May). Japan was therefore the only remaining target for the bomb, which would not be ready for some weeks yet. At the suggestion of General Groves, a Target Committee was established, chaired by his deputy, General Thomas Farrell. Its purpose was, in Groves’s words, “to make plans for the bombing operation itself, even though we still had no assurance that the bomb would be effective.” Among the members were five scientists, including John von Neumann and William Penney, air force officers, and other project staff. Groves addressed the initial meeting of the group on 27 April and in his usual blunt style first reminded all present of the need for secrecy. He then went on to suggest, before departing, that four potential targets in Japan should be identified for attack in July, August, or September. They should be within the B-29’s range of fifteen hundred miles. An air force meteorologist gave the bad news that the summer months were the least likely to provide the clear weather required for the bombing. Of the three months specified, August was relatively the best.

The group went on to consider basic targeting criteria, using guidelines given to Farrell by Groves, who recalled them in his autobiography: “I had set as the governing factor that the targets chosen should be places the bombing of which would most adversely affect the will of the Japanese people to continue the war. Beyond that, they should be military in nature, consisting either of important headquarters of troop concentrations, or centers of production of military equipment and supplies. To enable us to assess accurately the effects of the bomb, the targets should not have been previously damaged by air raids.” By the end of the first meeting, the committee had chosen seventeen targets for initial study. William Penney was asked to consider “the size of the bomb burst, the amount of damage expected, and the ultimate distance at which people will be killed.”

The committee next met at Los Alamos on 1 o and 1 1 May—two days after the German surrender. Robert Oppenheimer, Deak Parsons, Hans Bethe, and several other project staff also attended. Bethe gave his latest guesstimates of yields from the bombs: five thousand to fifteen thousand tons of TNT equivalent for the uranium bomb, Little Boy, and, with less confidence and subject to the forthcoming Trinity test, seven hundred to five thousand tons for the plutonium bomb, Fat Man. A detailed discussion followed of the best height at which to detonate the bombs to produce maximum impact from the blast, since this was governed by their yield.

Moving on to the targets themselves, the committee refined their criteria: “(1) They be important targets in a large urban area of more than three miles diameter, (2) they be capable of being damaged effectively by a blast, and (3) they are likely to be unattacked by next August.” The committee also agreed “that psychological factors in the target’s selection were of great importance. Two aspects of this are, (1) obtaining the greatest psychological effect against Japan and (2) making the initial use sufficiently spectacular for the importance of the weapon to be internationally recognized when publicity on it is released.”

Five cities were selected. First was Kyoto, “an urban industrial area with a population of 1,000,000… the former capital of Japan… from the psychological point of view there is the advantage that Kyoto is an intellectual center for Japan and the people there are more apt to appreciate the significance of such a weapon as the ‘gadget’ [the atomic bomb].” Second on the list was Hiroshima and its 350,000 inhabitants, “an important army depot and port of embarkation in the middle of an urban industrial area. It is a good radar target and it is such a size that a large part of the city could be extensively damaged.” Next was the port city of Yokohama near Tokyo, followed by the Kokura arsenal, and finally the port of Niigata on the northwest coast of Honshu. The committee considered but rejected a direct strike at the apex of the Japanese power structure: “The possibility of bombing the emperor’s palace was discussed. It was agreed that we should not recommend it but that any action for this bombing should come from authorities on military policy.”

The third meeting was held in the Pentagon on 28 May, with Paul Tibbets present to report on the operational readiness of his crews. The committee finally recommended three cities as targets and to be exempted from conventional air attack. They were Kyoto, Hiroshima, and Niigata. Aiming instructions were much simplified: “to endeavor to place first gadget in center of selected city” and significantly “to neglect location of industrial areas as pin point target, since on these three targets such areas are small [and] spread on fringes of cities.”

This recommendation was not entirely in line with the thinking of a more senior committee that met three days later. At the end of April Secretary of War Henry Stimson had agreed with President Truman to chair a committee to advise on nuclear energy policy while the topic was entirely secret and before it could be put to Congress for decision. It thus became known as the Interim Committee.