By chance also on April 25, Secretary Stimson and General Leslie Groves, the two men in charge of the Manhattan Project, visited the White House. They reported that “within four months” the United States would “in all probability have completed the most terrible weapon ever known in human history.”18 They brought with them a twenty-four-page report. The president read it and said that the enterprise sounded immense and technical. They discussed the weapon’s international implications, particularly for “the Russian situation,” which presumably meant its political use in regard to Soviet moves in Eastern Europe. General Groves reminded them, however, of “the dangers of over-emphasizing the power of a single bomb.”19
On May 6, Churchill mentioned the desirability of having a Big Three conference, and Truman’s first thought was to have it in the United States, perhaps in Alaska. However, Soviet expert “Chip” Bohlen said that was not a good choice. He told the president that part of the reason for the failure to carry out the Yalta agreements was the Soviet “opposition” that Stalin encountered upon his return home. So the dictator supposedly needed to be closer to home to communicate better.20 Such fantasies as this one about resistance to Stalin should tell us just how little the Soviet regime was understood at the time in the West, even by the experts. If Stalin had appeared badly weakened in 1941, his grip on power was gradually restored and then confirmed by the great victories.
The three Allied leaders finally opted for Potsdam, just outside Berlin, but when would they meet? That is an important question because some Russian and American revisionist historians suggest that Truman wanted to postpone the conference until the experiment on the first atomic bomb succeeded, when he would have had more political clout. However, the documentation does not support that view.21 It is also an exaggeration to claim that Truman already recognized the importance of the bomb and initiated a consistent policy based on it. As a matter of fact, he reacted haltingly to news about work on the weapon. Only on May 1 did he accept Stimson’s suggestion to name an interim committee that would recommend action to him, if and when a bomb was successfully tested. Even then he did not immediately name his own representative to the committee.22
Churchill—who was informed about the atomic research—wanted talks with Stalin sooner rather than later, preferably in mid-June. The Kremlin leader had already scheduled the great Victory Parade for June 24 and was content to accept Truman’s suggestion for July.
Indeed, none of the Big Three leaders quite realized that a new atomic age was at hand. As for the American military establishment, the Joint Chiefs of Staff proceeded on course without taking the atomic bomb into account. On May 25, and remarkably enough without telling the president, the chiefs issued orders to subordinate commanders in the field to draw up plans for the invasion of Japan. On May 28, General Douglas MacArthur delivered the strategy (Operation Downfall). There would be a two-pronged attack, the first of which was code-named Operation Olympic and the other called Coronet. So completely was the president kept out of the picture that on June 17 he still confided in his diary that he was struggling with “the hardest decision to date,” namely the question, “shall we invade Japan proper or shall we bomb and blockade.” This latter approach was the ongoing one, and it was not code for the atomic bomb. The first successful A-bomb test, Trinity, was still almost a month away.23
The intelligence about Western atomic research in May 1945 had come to NKVD chief Beria, who reacted slowly. When Soviet scientists wrote to the Politburo (Stalin) asking to accelerate work on the bomb, they received only a muted response.24 Caution is advised in interpreting what was in the mind of the wily Stalin, who knew more than he was prepared to divulge. His spies had informed him early on about the development of the ultimate weapon, the atomic bomb. The British had made progress in this field since 1941, as Soviet intelligence sources soon reported. By March the next year, Beria recommended setting up a committee to evaluate the information and to involve Soviet scientists. In early 1943, Molotov gave high-level authorization to proceed, but the effort was still modest.25
Although some Western scientists like Danish physicist Niels Bohr, who worked on the American bomb in Los Alamos, grew concerned and wanted to share the secrets of the research with the Soviets, Roosevelt and Churchill were decidedly against doing so. In September 1944 they signed an agreement to continue Anglo-American cooperation to develop “tube alloys” (code for the atomic bomb). They wanted Bohr investigated “to ensure that he is responsible for no leakage of information, particularly to the Russians.”26
But leakage occurred, enough for Stalin to resent his allies for not sharing secrets with him. That was a curious response from someone who at that very moment had an army of spies working inside the halls of power in Washington and London. In fact, later internal U.S. investigations revealed that during the war more than two hundred Americans were spying for the Soviets. They had infiltrated all sections of FDR’s administration, including the Office of Strategic Services (OSS), the forerunner of the CIA. This news came to light only in the late 1940s and early 1950s.27
Stalin even had top informants inside the Manhattan Project—the industrial-scale attempt to build the atomic bomb—including Klaus Fuchs, an émigré and active Communist from Germany. In Britain he became involved in atomic research and moved to New York in 1943. He and other scientists made it possible for the Kremlin, by 1945, to get “a clear general picture” of the secret project.28 Although Soviet leaders were a long way from realizing the full potential of atomic research, they eventually produced something that was close to a copy of the U.S. bomb. Given the scale and scope of Soviet espionage, it was certainly disingenuous for Stalin to express hurt feelings that his allies did not trust him, a man notorious for trusting no one.29
Because of his clash with Molotov, some revisionists as well as Russian historians have pigeonholed Truman as being anti-Soviet from the start. It was true that back in June 1941 (just after the Nazi attack on the Soviet Union), Truman was quoted as making the intemperate remark: “If we see that Germany is winning we ought to help Russia and if Russia is winning we ought to help Germany, and that way let them kill as many as possible, although I don’t want to see Hitler victorious under any circumstances.”30 This incautious quip was typical of the isolationist bluster of the times and was quoted in Soviet studies as being indicative of President Truman’s worldview and policies.
On balance, in April 1945 Moscow saw Truman as likely less inclined to be understanding of the Soviet position than FDR had been. That was what the Soviet embassy in Washington reported.31 To reassure the Soviets of his goodwill, the president turned for advice not to a hawk but to the best-known dove in the United States—none other than former ambassador to the Soviet Union Joseph E. Davies. On April 30, 1945, Davies was invited to the White House, where he offered his counsel. Truman told him what he had said to Molotov and then boyishly asked how he had done, hoping for a pat on the back. The American ambassador bit his tongue and then patiently explained why it was necessary to adopt Roosevelt’s old position of balancing between Stalin and Churchill “for the purpose of keeping the peace.”32