The scientific and technical knowledge that led in 1945 to the explosion of the first atomic weapons cannot be erased; as long as our civilization survives, so will our capacity to build nuclear weapons. Awareness of this harsh fact has sparked numerous attempts to control their spread. The hope was that nuclear weapons could be confined to a relatively few, politically stable countries and then eliminated entirely.

In the Baruch Plan of 1946, the United States offered to turn over its nuclear monopoly to an international authority on the condition that other powers do the same and that the most rigorous safeguards and inspection/verification procedures be established and enforced The Soviet Union declined to go along. Thus the 1950s and early ’60s saw the spread of nuclear weapons, first to the Soviet Union (accomplished by a combination of internal research and international espionage), then to Great Britain and France, and later to the People's Republic of China (instigated by the USSR and doubtless regretted by the Soviets today)