Historians today agree that ending World War II dominated the president's thinking in the summer of 1945. However, for many years "revisionists" contended that Truman's desire to practice what the scholar Gar Alperovitz aptly called "atomic diplomacy" strongly affected his decision to authorize the nuclear attack on Japan. According to this thesis, Truman sought to influence Soviet policy by dramatically proving that the United States possessed an unprecedentedly destructive weapon that American leaders were willing to use against an enemy. With one awesome stroke Truman could show his mettle as a tough warrior, end the war, depreciate the Soviet Union's claim to share in the occupation of Japan, and discourage Soviet communism's expansion into Europe and Asia. Overstated though it was, the Alperovitz thesis described one very real rationale for dropping the atomic bombs on Japan, and Truman certainly anticipated that a great geopolitical advantage would accrue to the United States from its atomic monopoly. What he did not foresee was the vehement reaction of Soviet Premier Joseph Stalin, who interpreted the atomic bombing as an anti-Soviet action disruptive to the postwar balance of power. No matter how unrealistic it was in the first place, any lingering hope of Soviet-American harmony in the early postwar world was doomed on 6 August 1945.
In a radio address delivered the day Nagasaki was bombed, President Truman elaborated the fundamental tenet of his postwar nuclear policy. Because the atomic bomb "is too dangerous to be loose in a lawless world," he warned, "Great Britain and the United States, who have the secret of its production, do not intend to reveal the secret until means have been found to control the bomb so as to protect ourselves and the rest of the world from the danger of total destruction." It soon became obvious that in the minds of American policymakers, "control" connoted some kind of global inspection system.
At first, prospects for negotiating the international regulation of atomic weapons appeared deceptively bright. In December 1945 the foreign ministers of the United States, Great Britain, and the Soviet Union met in Moscow. They jointly proposed the creation of an atomic energy commission responsible to the United Nations Security Council, where a veto precluded any action abhorrent to one of the five permanent members. The guidelines for the proposed commission also included the inspections demanded by President Truman.
On 24 January 1946 the General Assembly voted unanimously to form the UN Atomic Energy Commission (UNAEC) precisely as envisioned by the three foreign ministers. In June the commission met to forge the machinery for controlling atomic weapons. The American delegate, Bernard Baruch, immediately derailed the negotiations by introducing the concept of an International Atomic Development Authority that would operate independently of the Security Council. This autonomous body would have the power to punish, possibly by atomic attack, any nation that violated its pledge not to construct nuclear weapons. In a single sentence that broke the Moscow agreement, Baruch tersely explained the American rejection of the Security Council as the ultimate punitive agency of the United Nations: "There must be no veto to protect those who violate their solemn agreements not to develop or use atomic energy for destructive purposes."
Baruch's astringent tone reflected the views of a president increasingly worried by the deterioration of American relations with the Soviet Union. During the spring of 1946 the Soviet Union and the United States had failed to agree about the admission of Soviet satellite states to the United Nations, the composition of the Security Council's military arm, and the future of Germany. Moreover, Truman was upset by Soviet penetration of Iran and Manchuria, the latter an area of historic interest to the United States. According to the official historians of the U.S. Atomic Energy Commission, the president recalled the Manchurian crisis of 1931 and 1932, reasoning that if Secretary of State Henry L. Stimson had been able to threaten the use of force at that time, World War II would have been avoided. For all of these reasons, Truman decided that the veto rendered the Security Council impotent against any transgression by the Soviet Union.
By the middle of 1946 the Soviet Union had also shifted its position on the international regulation of nuclear weapons. Five days after Baruch spoke, the Soviet delegate, Andrei Gromyko, addressed the UN Atomic Energy Commission. Ignoring the American's remarks, Gromyko proposed a multilateral treaty binding the signatories to destroy "all stocks of atomic weapons whether in a finished or unfinished condition" within three months. The Russian made no provision for inspections to ensure compliance, thus rendering his proposal utterly unacceptable to an American president who refused to "throw away our gun until we are sure the rest of the world can't arm against us."
Truman was not the only senior American to favor the threatening metaphor of a gun. In September 1945, at a reception held during a London meeting of the foreign ministers of the United States, Soviet Union, and England, Secretary of State James F. Byrnes chided Soviet Foreign Minister Vyacheslav M. Molotov, "If you don't cut all this stalling and let us get down to work, I am going to pull an atomic bomb out of my hip pocket and let you have it." This crude sortie into atomic diplomacy led to what the historian Gregg Herkin has described as Molotov's "reverse atomic psychology." The durable old Bolshevik made several dismissive jokes of his own, the import of which was to let the United States know that Byrnes "could not use the threat of the bomb to gain political concessions from the Soviet Union."
As hope for the international control of atomic weapons waned at the United Nations, the Truman administration began to shape a coherent nationalistic nuclear policy. The domestic political impediments were formidable. Congress was demanding sharply reduced postwar military expenditures and rapid demobilization of all branches of the armed forces. The army, for example, shrank from more than eight million men to fewer than two million in nine months. In this postwar environment, Truman won approval only for establishment of the Strategic Air Command (SAC) in March 1946 and a test of the effectiveness of atomic weapons against ships at Bikini atoll later in the year.
Watchful waiting characterized American foreign policy immediately after the failure of the Baruch plan. Then, beginning in February 1947, a series of crises swept the noncommunist world. Britain's announcement of its inability to continue to sustain anticommunist forces in Greece and Turkey elicited an immediate promise of aid from President Truman, the first formal step toward the policy of containment. For sixteen months international tension mounted; in June 1948 it reached a peak with a Soviet blockade of land routes to West Berlin.
American nuclear diplomacy during that year and a half focused more directly on Great Britain than on the Soviet Union. In highly secret wartime agreements, Prime Minister Winston Churchill and President Franklin D. Roosevelt, with the approval of the Belgian government-inexile, had apportioned the rich Belgian Congo (Democratic Republic of Congo) uranium ore reserves to Britain and the United States on an equal basis. At Quebec, in 1943, they also had agreed that neither nation would use atomic weapons in war without the consent of the other. By mid-1947 policymakers in Washington viewed these two agreements as detrimental to the United States. In order to enlarge its nuclear arsenal, the United States needed more than half of the annual supply of the Congo's ore. To exercise full control over its own foreign and military policies, Washington had to eliminate London's voice in the use of atomic weapons. Britain finally agreed to these American demands in December 1947, receiving in exchange the promise of technical aid in the search for peaceful uses for atomic energy.
The military facet of Anglo-American nuclear interdependence manifested itself in the early weeks of the Berlin blockade (June 1948–May 1949), when the British permitted the newly autonomous U.S. Air Force to deploy to England three squadrons of B-29 bombers, which may have been modified to carry atomic bombs. This deployment was the first forward staging of American strategic airpower since World War II. It complemented the growing emphasis on military aviation within the United States, as evidenced by appointment of the aggressive General Curtis E. LeMay to head SAC, accelerated development of long-range atomic bombers, and agitation in Congress and the new Department of Defense for a seventy-combat-group air force. The American search for overseas air bases to encircle the Soviet Union and threaten it with nuclear attack began in earnest with the creation of the North Atlantic Treaty Organization (NATO) in 1949.
In August 1949 the Soviet Union successfully detonated an atomic bomb, ending the American nuclear monopoly fifteen years earlier than anticipated by Washington. Secretary of State Dean Acheson, Secretary of Defense Louis Johnson, and members of the powerful Congressional Joint Committee on Atomic Energy pleaded with President Truman to counter the Soviet technological surge by building a hydrogen bomb. The outgoing chairman of the Atomic Energy Commission (AEC), David Lilienthal, openly expressed the fear of such scientists as J. Robert Oppenheimer that it was morally wrong for the United States to base its foreign policy on "a weapon of genocide." But other equally prominent scientists, notably the nuclear physicists Ernest O. Lawrence and Edward Teller, argued the Soviet Union would surely try to outflank the American preponderance in fission weapons by developing a fusion weapon, or H-bomb, as quickly as possible. The only way for the United States to retain overall predominance in nuclear weapons technology was through creation of the hydrogen bomb, which Truman ordered in January 1950. He simultaneously directed a thoroughgoing reassessment of American foreign and military policy by the State Department, Department of Defense, and National Security Council (NSC). By April, Paul Nitze of the State Department had written NSC 68, a blueprint for the future that Truman approved in September.
NSC 68 was a stark document whose authors attributed to Moscow a "fundamental design" of completely subverting or forcibly destroying the governments and societies of the non-Soviet world and replacing them with "an apparatus and structure subservient to and controlled from the Kremlin." Only the United States had the potential to thwart Russian expansionism and ultimately "foster a fundamental change in the nature of the Soviet system." But successful containment would require that America increase its own political, economic, and military power and aid its allies in strengthening themselves. To ensure maximum American strength, NSC 68 discouraged seeking a negotiated control of atomic energy because agreement "would result in a relatively greater disarmament of the United States than of the Soviet Union." Looking ahead to 1954, when the Soviet Union presumably would possess a substantial atomic stockpile of its own, NSC 68 postulated a time of maximum danger during which the Soviet Union could lay waste the British Isles, destroy the communications centers of western Europe, or devastate "certain vital centers of the United States and Canada."
This suspicious and bellicose attitude permeated the highest levels of the executive branch when the advent of the Korean War in June 1950 loosened congressional constraints on massive military expenditures. President Truman immediately sought and obtained supplemental appropriations for the defense budget. By 1952 he had nearly quadrupled annual military spending, which had averaged about $15 billion since 1946. Although the president allocated a great deal of the hugely expanded sum to Korea and the buildup of conventional forces for NATO, the increase also made possible an exponential enlargement of the American capacity to wage nuclear war.
Truman moved on several fronts. First, he accelerated production of a hydrogen bomb. In theory, H-bombs can have unlimited explosive power, and their deadly radiation effects vastly exceed those of atomic, or fission, bombs such as those unleashed on Hiroshima and Nagasaki. The Atomic Energy Commission successfully tested a fusion device on 1 November 1952. A viable hydrogen bomb was added to the American stockpile in 1956, a year after the Soviets had developed their own practicable H-bomb. The second most important item on President Truman's atomic agenda was multiplication of fission weapons. Discovery of rich uranium deposits in the American Southwest and construction of several plutonium-producing reactors contributed to this atomic proliferation, but the big breakthrough in sources came with the determination in 1951 that the amount of fissionable material required for a bomb could be cut in half by surrounding the nuclear core with a neutron shield. The new abundance of fissionable substances permitted a third advance, the creation of "tactical" nuclear weapons. General Omar N. Bradley, chairman of the Joint Chiefs of Staff, had publicly advocated this step in October 1949. Speaking as a soldier challenging the congressional popularity of the Strategic Air Command, Bradley argued that wars were won on battlefields, not by destruction of cities and factories. If Soviet armies massed to invade western Europe, tactical nuclear weapons could devastate them. Only in that manner could the thin divisions of NATO defeat a numerically superior foe.
Bradley won the endorsement of key nuclear physicists and congressmen. By the fall of 1951, Representative Henry Jackson of Washington State, a member of the Joint Committee on Atomic Energy, was urging an annual expenditure of between $6 and $10 billion for tactical nuclear weapons. Under this pressure, the Atomic Energy Commission moved energetically. In March 1953 it exploded a fifteen-kiloton device amid simulated battlefield conditions. Two months earlier, at President Dwight D. Eisenhower's inaugural parade, the army had displayed a cannon capable of firing nuclear projectiles.
The Truman administration and Congress created many highly sophisticated delivery systems for new weapons. The very high-altitude, all-jet B-52 Stratofortress bomber with a range of 7,000 miles was beginning to take shape as the principal strategic aircraft of the future. As a stopgap measure, to replace the piston-driven B-29 strategic bomber of World War II, Truman acquired bases from America's allies for the intermediate-range, six-jet-engine Boeing B-47. Congress allotted funds for the first aircraft carrier capable of launching jet-powered nuclear bombers, the Forrestal-class supercarrier with a flight deck nearly 1,000 feet long. The Atomic Energy Commission and Westinghouse designed a reactor to fuel some of the new aircraft carriers, but nuclear propulsion of submarines had the navy's highest priority thanks to the unrelenting vigor of one naval officer, Hyman G. Rickover. In June 1952 the keel was laid for a nuclear-propelled prototype, the USS Nautilus (SSN-571). It would signal "underway on nuclear power" on 17 January 1955.
At a rapid pace, the U.S. Navy fashioned and deployed two distinct types of nuclear-fueled submarines. The "attack boat," or SSN, came first. It was intended for the classic submarine role of striking ships or other submarines with torpedoes. Five years after Truman left office, Chief of Naval Operations Arleigh E. Burke prodded Congress to fund the first nuclear-driven, ballistic-missile-launching submarine (SSBN). Armed with ballistic missiles of ever-increasing range—first Polaris (1,200 nautical miles), later Poseidon (2,500 nm), finally Trident (4,000 nm)—this truly revolutionary weapons system aimed warheads at cities and other targets deep inland. It guaranteed the navy a permanent place in the strategic or nuclear "triad" of weaponry intended to deter Soviet attacks on the United States, or to launch a devastating retaliatory strike if deterrence failed.
Truman did not intend these weapons for limited war, but of necessity he had to consider the employment of atomic weaponry in the darkest days of the Korean War. On 30 November 1950, as Chinese troops swept General Douglas MacArthur's vastly outnumbered soldiers and marines south from the Yalu River, the president held a press conference. In answering a question about possibly dropping the atomic bomb on North Korea or China, he said, "There has always been active consideration of its use." He immediately added, "I don't want to see it used. It is a terrible weapon, and it should not be used on innocent men, women, and children who have nothing to do with this military aggression." But the doomsday alarm had been sounded. John Hersey, author of the widely read book Hiroshima, wrote, "There were glaring headlines in Paris.… Big headlines in Finland gave the impression that MacArthur had already received the go-ahead. In Vienna, the story had the lead in all the morning papers except the Soviet army sheet."
A thoroughly aroused House of Commons dispatched Prime Minister Clement Attlee to Washington to determine exactly what Truman was contemplating. At an extended series of high-level meetings in early December, the president attempted to mollify the Briton with the prayer that "world conditions would never call for the use of the atomic bomb." But he would not categorically rule out use of the bomb if the UN position deteriorated radically and MacArthur was in danger of being driven off the Korean peninsula. As it was, the UN forces stemmed the tide and the front was gradually stabilized roughly along the thirty-eighth parallel of north latitude, the original dividing line between North and South Korea.
General MacArthur has been popularly condemned for advocating the use of atomic weapons, as indeed he did. In December 1952 he told his former protégé, president-elect Dwight D. Eisenhower, "I would have dropped between 30 and 50 atomic bombs." But contemplation of a nuclear war in Korea was widespread in Washington between 1950 and 1953. The Joint Chiefs of Staff fantasized about implanting a cordon sanitaire north of the Yalu River with cobalt 60, a highly radioactive residue derived from reprocessed plutonium. Always eager to be involved in a bombing campaign, General Curtis LeMay, head of SAC, thought his airmen were well qualified to drop nuclear bombs because of their "intimate knowledge" of atomic weaponry. He almost got his chance. According to the historian Stanley Sandler, B-36s armed with nuclear weapons were deployed to Okinawa in June 1952 to induce the Chinese to sign an armistice. Across town from the Joint Chiefs of Staff, Representative Albert Gore, Sr., a member of the Joint Committee on Atomic Energy, believed radiating a large strip of the Chinese-Korean border was "morally justifiable" since Korea had become "a meat grinder of American manhood." In the supercharged atmosphere of early Cold War Washington, there was abundant domestic support for a nuclear war in Korea. The "buck" stopped with the president, as Harry Truman said it always did.
The American commander in chief refrained from authorizing atomic warfare against Korea or China partly out of belief that the Korean War was a Soviet feint and that the real communist attack would come in Europe, in which case the United States would need all of its nearly 300 atomic warheads. Moreover, by using atomic weapons the United States could spark North Korean retaliation against Pusan or other South Korean cities with Soviet-supplied atomic bombs. British disapproval and the racist implications of again employing the ultimate weapon against an Asian people contributed to Truman's restraint. Atomic diplomacy also helped stay his hand. In the opinion of one veteran of the Korean War, the historian Stanley Weintraub, Truman realized that if the bomb were used in Korea without producing "decisive results, it would lose credibility as a Cold War deterrent." The president therefore accepted a stalemate in conventional warfare in Korea while simultaneously fathering what Atomic Energy Commission chairman Gordon Dean described in September 1952 as "a complete 'family' of atomic weapons, for use not only by strategic bombers, but also by ground support aircraft, armies, and navies."