Before the Fallout

by Diana Preston

  · · ·

  Four months later, the Alsos mission reached Strasbourg in Alsace and went at once to the university to look for von Weizsacker. In his hurry to flee he had left a stack of revealing paperwork, including letters showing that the Kaiser Wilhelm Institute for Physics had moved to Hechingen. They even gave the address and phone number, making Goudsmit wish "we could fly to Switzerland and call them up from there!" He and his colleagues "studied the papers by candlelight for two days and nights until our eyes began to hurt." By the end of January 1945 Goudsmit felt confident enough to inform Washington that although the Germans were clearly investigating the military applications of nuclear fission, their work was still at an experimental stage and the immediate focus appeared to be nuclear power rather than weapons. In other words, "Germany had no atomic bomb."

  General Groves and U.S. military intelligence were reassured but wanted conclusive proof. With the war fast drawing to a close, Groves had an additional worry: how to prevent key German fission scientists and facilities from falling into the hands of the Russians. In February 1945 the Allies had agreed which zones of a defeated Germany each would occupy. Groves was especially concerned that the Auer Company uranium-processing factory at Oranien-burg outside Berlin would be in the Russian zone. He successfully arranged for it to be destroyed from the air, but keeping individuals out of Russian hands was more difficult. The Alsos team was detailed to locate and take into custody Germany's key atomic scientists.

  In late March 1945, following swiftly in the wake of Allied troops, the Alsos team crossed the Rhine, entered Heidelberg, and seized Walther Bothe's institute, home of Germany's only functioning cyclotron. Bothe, the scientist whose mistaken conclusions had convinced his colleagues that they needed heavy water, not graphite, as a moderator, was the first enemy scientist to be apprehended whom Goudsmit knew personally. Bothe shook Goudsmit's hand warmly but refused to talk about his military work.

  Moving on to Gottingen, Goudsmit met Morris "Moe" Berg, a former catcher for the Washington Senators and Boston Red Sox baseball teams, and now an American secret agent who had been involved in a scheme to capture, even to assassinate, Heisenberg. The idea of kidnapping Heisenberg had first been mooted in October 1942 when news of Heisenberg's appointment as director of the Kaiser Wilhelm Institute of Physics some months earlier first trickled through to refugee scientists in the United States. Their respect for Heisenberg's abilities had made them highly nervous of what he might achieve. After discussing the problem with Hans Bethe, Victor Weisskopf had sent to Robert Oppenheimer a three-page letter stating their concerns. "By far the best thing," Weisskopf had suggested, "would be to organize a kidnapping." He even volunteered to undertake the mission himself. Oppenheimer thanked him for his "interesting" letter, which he had submitted "to the proper authorities," but told Weisskopf, "I doubt whether you will hear further of the matter."

  However, the idea had not gone away. In December 1944 U.S. special operations had sent Moe Berg to Zurich, where Heisenberg was to lecture, with a gun in his pocket and orders that if Heisenberg said anything suggesting that German scientists were close to making an atomic weapon, Berg was to shoot him dead in the auditorium. Berg had hung on Heisenberg's words but heard nothing to convince him to fire his gun. Later, Berg engineered an introduction to Heisenberg and accompanied him on a long walk through ill-lit streets back to Heisenberg's hotel, during which he badgered him with questions. Berg was a good linguist and spoke German well. Heisenberg, who had no idea his life was hanging on what he said, assumed the pushy stranger was Swiss. Unsurprisingly, he responded guardedly and again revealed nothing implying that Germany possessed a war-winning weapon. Indeed, Heisenberg seemed regretfully resigned to Germany's losing the war. Berg allowed him to leave Switzerland unharmed.

  Moe Berg

  Berg's reassuring view of the relative poverty of the German nuclear capability did not distract Alsos from urgently tracking down German scientists and facilities. High on their list was Diebner's German Army Ordnance fission project operating at Stadtilm, to which papers found in Heidelberg had alerted them. Immediately on hearing that Stadtilm was in Allied hands, Goudsmit flew there from Paris, only to discover that the Gestapo had whisked away Kurt Diebner and several trucks of equipment two days earlier. However, he got his first look at part of the German fission program: "It was located in an old school-house. The cellar of that place looked almost like a natural cave and seemed quite bombproof. It was there that our men found the few remaining physicists huddled together with their families."

  A few days later at the town of Celle, north of Hanover, the Alsos team discovered an isotope-separation laboratory hidden away by Paul Harteck in a parachute silk factory. Harteck himself had fled, but a brief examination of the centrifuge he had been developing satisfied Goudsmit that it "would have taken a hundred years" to produce sufficient quantities of U-235 for a bomb. Even more important, soon afterward, an Anglo-American strike force located the bulk of the uranium taken by the Germans from Belgium and seized it from under the noses of advancing Russian troops near Magdeburg. On 23 April 1945 Groves told the army chief of staff, General George Marshall, categorically that the risk of a German nuclear weapon was over.

  That same day, Colonel Pash, rushing to get there in advance of French troops, reached Haigerloch. He feared attack by the "Werewolves," a fanatical Nazi resistance group, but as he drove in, white pillowcases, sheets, and towels fluttered from every window. His men quickly found Heisenberg and von Weizsacker's secret German laboratory. Pash later wrote that it was an "ingenious set-up" camouflaged and protected by "a church atop a cliff." He found "a box-like concrete entrance to a cave" in the side of the cliff. Inside was "a concrete pit about ten feet in diameter. Within the pit hung a heavy metal shield covering the top of a thick metal cylinder. The latter contained a pot-shaped vessel, also of heavy metal, about four feet below the floor level." It was, Pash realized, "the Nazi uranium 'machine.'" In another chamber containing a series of cylinders he found a blackboard on which was chalked "Let rest be holy to mankind. Only crazy people are in a hurry."

  Leaving a team to photograph and dismantle the contents of the cave, Pash moved on to nearby Hechingen. The first thing he saw on entering Heisenberg's office in the woolen mill chosen to house the Kaiser Wilhelm Institute for Physics was the surreal sight of a photograph of Heisenberg and Goudsmit taken in 1939 at Ann Arbor. Heisenberg, in Goudsmit's view "the brains of the German uranium project," was gone. However, Goudsmit, who arrived there soon afterward from Haigerloch, was able to begin interrogating some twenty-five captured scientists and technicians. They included von Weizsacker, who had quickly been apprehended, Karl Wirtz, one of Heisenberg's key assistants in Berlin, and Erich Bagge and Horst Korsching, who had both been working on isotopic separation. Von Weizsacker objected that the latter were too junior and insignificant to detain. According to Goudsmit, he remarked, "What kind of selection is this?" Goudsmit had also taken Max von Laue into protective custody. He knew that von Laue had no direct connections with the nuclear work, but he respected him deeply and believed he should play a part in the reconstruction of science in postwar Germany.

  Goudsmit learned from von Weizsacker that his final contribution to the German war effort had been to lower a sealed metal drum containing key research notes into a stinking cesspit. The drum was retrieved. So were three drums of heavy water and the uranium used in the Haigerloch reactor that Heisenberg had ordered to be buried. The Alsos team celebrated their success by consuming the contents of von Weizsacker's wine cellar, which they had also discovered.

  The Alsos team withdrew just before French Moroccan troops swept into Hechingen. Pash headed next for Tailfingen and Otto Hahn. Pash found Hahn and his entire staff assembled calmly in their laboratory. Hahn was extremely cooperative. As Pash recalled, he "unhesitatingly" produced a pile of scientific reports and volunteered his viewr that a nuclear bomb could not be built. Goudsmit took him too into custody.
/>   In early May in Bavaria, the Alsos team caught up with Walther Gerlach and Kurt Diebner. They also finally captured their primary target, Werner Heisenberg. At 3 o'clock on the morning of Friday, 20 April, he had cycled out of Hechingen into the darkness, determined to reach his wife and children 1 20 miles away at Urfeld. He completed the journey, evading fire from low-flying Allied aircraft and equally dangerous groups of hard-line Nazis roaming the countryside shooting or hanging anyone they took it into their heads to suspect of disloyalty to the Fatherland. When, a few days later, Pash arrived to arrest him, Heisenberg's initial reaction was relief. He later recalled he felt "like an utterly exhausted swimmer setting foot on firm land." However, knowing that he had to leave his wife and children behind and fearing that the locals would treat them harshly if he was seen to cooperate, he begged Pash to make it look as if he was being arrested against his will.

  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.

  TWENTY-TWO

  "A PROFOUND

  PSYCHOLOGICAL IMPRESSION"

  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.

  Stimson recommended that the president appoint "a personal representative of himself." He chose James Byrnes. Among the other members were Van­nevar Bush and James Conant. The committee quickly spawned a scientific advisory panel comprising Arthur Compton, Enrico Fermi, Ernest Lawrence, and Robert Oppenheimer. Although the topic did not fall within its initial terms of reference, the Interim Committee discussed the deployment of the bomb on 31 May and 1 June, with its scientific advisory panel in attendance.

  As is often the case, some of the most important discussions were informal ones. On this occasion they took place not in the men's rooms but around the lunch tables. Lawrence, in discussion with Byrnes, proposed that the bomb "ought to be demonstrated to the Japanese in some innocuous but striking manner, before it should be used in such a way as to kill many people." In a discussion that lasted no more than "perhaps ten minutes," according to Lawrence, much cold water was poured on Lawrence's idea. Oppenheimer could not envisage a demonstration that would be "sufficiently spectacular to convince the Japs that further resistance was useless." Byrnes was concerned that if the Japanese were warned of impending nuclear attacks, they might move Allied prisoners of war into the target areas. Certainly their air defenses, such as they were, would be activated. Others worried about what would happen if a supposedly imposing demonstration were to fail. Stimson suggested that casualties from an attack would be unlikely to differ significantly from those resulting from the massive fire raids on cities such as Tokyo.