Nuclear warfare

Nuclear warfare is the use of nuclear weapons in war, a possibility that began with the first atomic test at Trinity in New Mexico in July 1945. In August 1945 the United States dropped atomic bombs on Hiroshima and Nagasaki, the only time such weapons have been used in conflict. After the Soviet Union tested its own bomb in 1949, the Cold War brought a nuclear arms race and the doctrine of deterrence, in which each side was restrained by the threat of mutual destruction. Treaties such as the Nuclear Non-Proliferation Treaty and various arms-control agreements aimed to limit the danger. The risk of nuclear war, from crises like Cuba in 1962, has shaped international politics ever since.

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