The man who gave Oppenheimer leadership of the bomb program, who brushed aside fears that Oppie was a security risk despite what he termed the scientist’s ‘very extreme liberal background’, was Leslie Groves, who was chosen, in September 1942, to take charge of what was now guardedly called the Manhattan Project. The atomic program had not been Groves’s choice. He was 46 years old in 1942 and still a colonel. He hankered for a combat assignment and a promotion to general, especially after overseeing construction of the Pentagon, a job that had pedestrian satisfactions. It was time, he thought, for some excitement.28
It was, but not through combat. Groves was picked to guarantee careful military oversight of the bomb project. Vannevar Bush wanted an army man to place a firm hand on it. Fermi had not run his pile yet, and in the fall of 1942 the bomb program generally remained a small part of the massive mobilization effort the United States had undertaken to that point. But there was promise, and, if someone tough and competent could be found to lead the enterprise, its promise might be fulfilled. Groves’s military superiors had Groves in mind from the start. When he first met Groves on the afternoon of his appointment, Bush was not sure the generals had made the right choice. Groves, who weighed nearly 300 pounds (he had a taste for chocolate creams, a supply of which he kept in his office safe), came on strong, even to the patrician Bush. He was prudish (having been raised by a father who was a Presbyterian army chaplain of abstemious habits), brusque to the point of rudeness, overbearing, and contemptuous of sentiment. ‘I’m afraid he may have trouble with the scientists,’ Bush anxiously told an officer after the meeting. To Harvey Bundy, the special assistant to Secretary of War Henry L. Stimson, Bush said: ‘I fear we are in the soup.’ When Groves got home that evening, he told his wife and daughter, and wrote to his son, then at West Point, that he had a new, secret job that no one was to talk about.29
If Groves got off on the wrong foot with Bush, he nevertheless quickly established himself as a demanding and effective advocate for his new cause. On his first full day on the job, Groves sent his assistant, Lieutenant Colonel Kenneth Nichols—‘uninspired but punctilious’, according to Peter Wyden—to New York to strike a bargain with Edgar Sengier, the Belgian head of Union Miniere du Haut Katanga, who was, it may be recalled, sitting on more than 1,200 tons of uranium and prepared to do business. Nichols made the deal, sanctified on a sheet of yellow scratch paper. The following day, a Saturday, Groves authorized purchase of a substantial plot of land in Tennessee, for the purpose of building an enormous plant for the creation of uranium isotopes, and he met Donald Nelson, head of the War Production Board, whom he bullied into assigning the Manhattan Project the government’s highest priority rating, loosening bottlenecks and cutting red tape that had previously frustrated the bomb effort. On 23 September, minutes after he had been promoted from colonel to brigadier general, Groves met Stimson, Bush, Conant, and a few others. Stimson suggested a committee of seven to manage the project. Groves countered with a request for just four—Bush, Conant, a navy representative, and himself1—and Stimson acceded. At this point, Groves rose and said he had to leave: he was on his way to Tennessee and did not want to miss his train. Bush began to think that Groves had been a good choice after all.30
Groves seems to have braced himself to deal with the Manhattan Project scientists. He was an engineer, and proud of his grasp of mathematics, but he knew nothing about quantum physics, a disability in his own mind that he sought to cover with bluster. He came to Chicago on 5 October to inspect Arthur Holly Compton’s Met Lab. Groves and Compton, both sons of Presbyterian ministers, found they nevertheless had differences: Groves referred privately to Compton, for some reason, as ‘Arthur Hollywood’, while the gentler Compton thought Groves guilty of an ‘unfamiliarity with scientists’. The two men were ultimately reconciled. Not so Groves and Leo Szilard, whose animosity toward each other was legendary, and in high relief emblematic of the mistrust that existed between scientists and the military men assigned to keep them on task. (The Groves-Szilard feud began at the Met Lab, when Groves, out of his depth, insisted on discussing with Szilard cooling systems for nuclear reactors.) The Chicago scientists ran some equations for their visitor. At one point Groves caught a small transcribing error, which the offending scientist remedied with a finger stroke, leaving Groves smug about his own expertise yet worried at the feckless imprecision of the men and women in his charge. ‘Dr Compton, your scientists don’t have any discipline,’ Groves insisted later. Compton remonstrated that ‘responsible’ scientists had a kind of discipline, but that it was ‘not possible for anyone to tell a scientist what he must do’. However calmly put, that was exactly what Groves feared.31
The general went next to Berkeley, and Ernest Lawrence’s Radiation Lab. Still on his mettle because of his experience in Chicago, Groves thought Lawrence was trying to patronize him with breezy talk about his cyclotron—engineer’s talk, perhaps, but not what Groves wanted to hear. He wanted to know how much U-235 Lawrence was making, and how quickly. When Lawrence confessed that the separation process remained in its infancy, Groves steamed. ‘Professor Lawrence,’ he said, in front of the Rad Lab staff, ‘you’d better do a good job. Your reputation depends on it!’ Lawrence was stunned, but only temporarily; he got his own back at lunch: ‘General Groves, you know... my reputation is already made. It’s your reputation that depends on this project.’ Thereafter the relationship improved; it worked best to stand up to Groves. But Lawrence still could not say much about U-235 production, and in particular about its necessary level of purity. For that, Lawrence suggested, the general should ask Robert Oppenheimer.32
Groves and Oppenheimer looked so unlike each other that it was funny: ‘Godzilla meets Hamlet,’ someone later said. Their backgrounds, politics, and areas of expertise were dramatically different. Yet both men, insecure in their positions, wanted to make a mark, do something extraordinary, and they seem to have recognized in each other a means of doing that. Or maybe something just clicked. Groves admired Oppenheimer’s high intelligence and knew of his reputation in physics. While he, like others, had serious concerns about Oppenheimer’s administrative abilities—‘he couldn’t run a hamburger stand’, exclaimed a colleague—Groves believed that he himself could manage the administration of the program, leaving Oppenheimer to keep the scientists focused on building a bomb. As for Oppie’s ‘left-wandering’ politics, Groves preferred to have the physicist close at hand, where he could keep an eye on him. A week after first meeting him in Berkeley, Groves summoned Oppenheimer to Chicago. They met, with Nichols and a second colonel, in a cramped compartment aboard a train bound for Detroit, and they talked for hours about the needs of the Manhattan Project. In the end, cognizant of the unorthodoxy of the appointment but unable to imagine or select a better candidate, Groves chose Oppenheimer to coordinate the construction of the world’s atomic bomb.33