Atomic bomb

The Atomic bomb passed through several roles during Harry S. Truman’s presidency: it was considered as a means of compelling Japan’s surrender, a weapon whose use carried a grave moral burden, a force the government sought to place under civilian control, and finally the measure of a new strategic rivalry with the Soviet Union. Its significance lay not only in destructive power. The bomb repeatedly tested what the President should know, what the public should be told, and who should make decisions about the weapon.

Wartime Use and the Question of Necessity

The decision to use the bomb was not presented as automatic. A demonstration against a non-city target had been considered and rejected by the committee and its scientific panel; the scientists could not propose a display likely to produce the tremendous shock thought necessary to persuade Japan. George C. Marshall had earlier considered using the weapon against a military objective, with warning before any attack on manufacturing centers, but by this stage that option was no longer the prevailing approach. The problem was how to make the weapon’s force consequential without leaving a misleadingly limited impression of its capacity.

At Potsdam, Truman later recalled a consensus among James F. Byrnes, Henry L. Stimson, William D. Leahy, Marshall, and General Arnold in favor of use. Marshall emphasized the lives an invasion might cost. As Truman recounted the discussion, Marshall estimated that an invasion of the Tokyo plain and other Japanese locations would produce at least a quarter of a million American casualties. Truman said he reached his own conclusion only after long and careful thought, and acknowledged that he disliked the weapon. The estimate supplied a military argument for use, but his reluctance remained part of the decision’s record rather than disappearing once the choice was made.

His private account also placed Japanese civilians within that calculation. Truman recognized Japan’s cruelty in wartime but resisted the idea that the United States should imitate it. He regretted the prospect of destroying whole populations because of their leaders’ refusal to yield, and said he would not do so unless it was absolutely necessary. He hoped that Soviet entry into the war might make Japan surrender soon, while describing his purpose as saving American lives and acknowledging concern for Japanese women and children. The bomb therefore stood at the intersection of anticipated military losses, the possibility of another route to surrender, and the harm its use could inflict on civilians.

Responsibility and Civilian Control

After the war, the bomb’s meaning extended beyond the moment of its use. On a speaking trip to the American Legion fair at Caruthersville, Missouri, Truman addressed atomic energy as one of the difficulties confronting the country. He had asked Congress to establish a new Atomic Energy Commission under civilian rather than military control, arguing that the release of atomic energy could not be understood within old assumptions. In public, he joined the question of control to a broader appeal for the Golden Rule. The contrast was stark: a revolutionary weapon demanded new institutions, while his public language appealed to a familiar moral principle.

The boundary between the President and the people who had worked on the bomb appeared in a private meeting with J. Robert Oppenheimer. Oppenheimer arrived agitated and said he felt responsible for bloodshed because of his work. Truman rejected the scientist’s expression of guilt, answering that responsibility rested with him and that he would bear it. The encounter exposed two different understandings of responsibility: the scientist’s distress over participation in the weapon’s creation and the President’s insistence that the political decision belonged to the office he held. Truman left the meeting hoping not to see Oppenheimer again.

Truman’s own knowledge of the weapon’s stockpile was also contested. He privately worried that peacetime atomic energy might shorten the working day and leave people idle, while his secretary of state, James F. Byrnes, was in Moscow and, Truman felt, was not keeping him adequately informed. At a December Cabinet meeting, Henry A. Wallace pointedly told the President that he ought to know how many atomic bombs were available, after Truman said he did not want to know. Truman conceded that he should know, then qualified his retreat by saying he knew in a general way. The exchange made the bomb an issue of presidential oversight as well as military capability: civilian authority could not be merely a formal principle if the President lacked basic information about the arsenal.

Tests, Secrecy, and the Soviet Challenge

The bomb also shaped decisions about public demonstrations and diplomacy. On March 22, Truman objected to the Navy’s invitation to about sixty members of Congress to witness planned atomic tests at Bikini Atoll before July 1, saying Congress had work to do. Byrnes called testing at that moment extremely ill-advised because of the possible effect on relations with the Soviet Union. Vice Admiral William Blandy reported that 37,000 men had already been assigned to the operation. Truman demanded a decision, and the discussion exposed competing costs: Byrnes preferred no tests at that time, Wallace agreed, and Truman warned that cancellation would waste $100 million. He decided that the tests would be postponed, though the account does not specify the eventual schedule. The bomb’s public display was thus treated as a matter with both domestic and diplomatic consequences.

The Soviet challenge first reached the administration as physical evidence. An Air Force weather-reconnaissance plane flying at 18,000 feet from Japan toward Alaska detected intense radioactivity over the North Pacific, east of the Kamchatka Peninsula. Further flights reported levels as much as twenty times above normal, and the Air Force followed the radioactive cloud across the Pacific nearly to the British Isles, where the Royal Air Force detected it. David Lilienthal hurried to Washington; by late morning he was consulting a hastily assembled advisory commission of nuclear scientists chaired by Oppenheimer. Oppenheimer judged that the Soviet Union had detonated an atomic bomb. The weapon’s international spread had become legible first not through a public announcement, but through traces in the atmosphere that aircraft and scientists could interpret.

Three days later, on September 23, Charlie Ross closed the White House press office door and distributed Truman’s mimeographed statement. Reporters rushed to telephones; in the scramble, they broke the head off a stuffed deer. The statement said that the American people were entitled to be informed of developments in atomic energy so far as national security allowed, and reported evidence that an atomic explosion had occurred in the Soviet Union. It also said that other nations would eventually develop the new force. That qualification did not soften the immediate shock: the Soviet explosion had come three to five years earlier than most predictions, ending a four-year American monopoly. There was no national panic, but Cold War fears and tensions intensified. The public announcement made the changed balance of power explicit, while its appeal to national security showed that disclosure still had limits.

From Atomic Monopoly to the Superbomb Debate

The Soviet explosion altered the weapon’s future as well as the present strategic balance. In October 1949, highly secret meetings began at the offices of the Atomic Energy Commission on a thermonuclear weapon, described as a superbomb or Super. The proposed weapon would have more than ten times the destructive power of the bombs used against Hiroshima and Nagasaki. Participants regarded the Soviet bomb as having changed the situation drastically: if the Soviet Union could produce an atomic bomb, it might also be able to pursue a more powerful one.

The sequence transformed the Atomic bomb from a weapon associated with the end of the war into the starting point of an escalating technological contest. Its destructive capacity forced Truman to confront responsibility and civilian oversight; its tests raised questions about military schedules, congressional participation, cost, and relations with the Soviet Union; and radioactive evidence revealed that American possession was no longer exclusive. The announcement of the Soviet explosion closed the brief period of monopoly, while the subsequent thermonuclear discussions showed how quickly the end of that monopoly could generate pressure for a still more powerful weapon.