An H-bomb, depending on its size, can produce an explosion powerful enough to devastate an area of approximately 150 square miles, while the searing heat and toxic radioactive fallout from such devices can impact an area of more than 800 square miles. The explosion of an atomic bomb by the Soviet Union in September 1949 ended the U.S. atomic monopoly and led to a nuclear arms race. The development of more powerful weapons such as the H-bomb and of new methods of delivering nuclear bombs, such as ballistic missiles, were primarily a result of the Cold War conflict and concomitant arms race.
In 1946 the U.S. Atomic Energy Act created the Atomic Energy Commission (USAEC). The USAEC was responsible for the development and control of the U.S. atomic energy program after World War II. The commission consisted of five members appointed by the president. A civilian advisory committee was also created, and Robert Oppenheimer, scientific head of the atomic bomb project, served as its chairman. The USAEC also worked with a military liaison with whom it consulted on all atomic energy issues that had military applications. By 1949, the year the Soviets exploded their first atomic bomb, Cold War tensions were running high. Nuclear physicist Edward Teller, USAEC Commissioner Lewis Strauss, and other scientists formed a coalition together with military officials to urge President Harry Truman to initiate a program to construct a superweapon, or H-bomb. This new weapon would be measured in megatons instead of kilotons and could yield an explosion equivalent to millions of tons of TNT. Despite opposition from Oppenheimer and several other nuclear scientists, Truman, under siege for being soft on communism, authorized an H-bomb program in January 1950.
It took the combined efforts of a number of scientists as well as Stanislaw Ulam, a mathematician, to solve the theoretical and technical problems related to building a hydrogen weapon. They carried out their work at Los Alamos, New Mexico, the same facility that had helped produce the atomic bomb. The prototype H-bomb was first detonated on 1 November 1952 on Enewetak Atoll in the South Pacific. The explosion virtually obliterated the island, creating a crater a mile wide and 175 feet deep. After the detonation of the prototype, scientists constructed an H-bomb that could be dropped by aircraft. That weapon was tested successfully in 1954. The Soviet Union tested its own H-bomb on 12 August 1953. The British also developed a hydrogen weapon, which they tested on 15 May 1957.
Unable to maintain a monopoly on nuclear weapons or to force the Soviet Union to alter its policies through either deterrence or the threat represented by nuclear arms, the United States instead found itself engaged in a nuclear arms race. Despite collective security agreements and pacts such as the North Atlantic Treaty Organization (NATO), the United States maintained that only nuclear superiority would guarantee the security of the United States and its allies. The launching of the first satellite to orbit Earth, the Soviet-built Sputnik 1 in 1957, represented a dual threat to the West. It seemed to suggest that Soviet scientists had pulled ahead of their American counterparts. More critically, it also posed the high probability of delivering nuclear weapons with missiles rather than by planes. As a result, the United States increased funding for its space program and redoubled its efforts to fully develop and deploy intercontinental ballistic missiles (ICBMs) and, later, submarine-launched ballistic missiles (SLBMs).
The rapid proliferation of nuclear weapons, of course, increased the threat of nuclear war, whether by accident or by choice. With the advent of H-bombs and ballistic missile systems that could hurl bombs at an adversary in a matter of minutes, most civil defense preparations became exercises in futility. The Soviet Union's installation of nuclear-tipped missiles in Cuba led to the Cuban Missile Crisis of October 1962. President John F. Kennedy imposed a naval quarantine around Cuba and refused to allow Soviet ships through the blockade. Faced with the real possibility of a catastrophic thermonuclear war, both sides engaged in a flurry of diplomacy. The Soviets backed down, dismantling the missiles by the end of the year. The Cuban Missile Crisis, one of the few direct confrontations between the Americans and Soviets, showed the potential peril of the nuclear arms race. After the crisis passed, both U.S. and Soviet officials sought new ways to avoid the unthinkable consequences of a nuclear exchange. In 1963, the Partial Test Ban Treaty had been agreed to by both sides, the first small step toward eventual nuclear arms reductions. The threat posed by nuclear weapons did not end with the collapse of the Soviet Union in 1991, although reduced tensions have lessened the potential for a full-scale nuclear conflict.
Millett, Allan R., and Peter Maslowski. For the Common Defense: A Military History of the United States of America. New York: Free Press, 1994.; Rhodes, Richard. Dark Sun: The Making of the Hydrogen Bomb. New York: Simon and Schuster, 1995.