Partial Test Ban Treaty
The 1963 treaty banning nuclear weapon tests in the atmosphere, outer space, and underwater. It left underground testing permissible.
Cuban Missile Crisis: A 1962 confrontation between the United States and the Soviet Union over Soviet nuclear missiles in Cuba. The crisis intensified both leaders’ interest in reducing the danger of nuclear escalation.
Atmospheric nuclear testing: Detonation of nuclear weapons in or above Earth’s atmosphere. The treaty prohibited this test environment, a major source of radioactive fallout.
John F. Kennedy: The 35th president of the United States, serving from 1961 until his assassination in 1963. Kennedy signed the treaty for the United States and urged its ratification as a first step toward arms control.
Nuclear arms control: Agreements and policies that limit, manage, or reduce nuclear weapons and related activities. The treaty became an early, durable agreement within the wider Cold War arms-control system.
Nuclear fallout: Radioactive particles deposited after a nuclear explosion, especially following atmospheric tests. Public concern over fallout helped build support for stopping tests in the open air.
Outer space: The region beyond Earth’s atmosphere, where orbital and other space activities occur. The treaty’s ban covered nuclear explosions in this environment as well as in the atmosphere.
Nikita Khrushchev: The leader of the Soviet Union from 1953 until 1964. Khrushchev agreed to the limited ban after broader test-ban negotiations had stalled.
Nuclear Non-Proliferation Treaty: A 1968 international treaty aimed at preventing the spread of nuclear weapons and promoting disarmament and peaceful nuclear cooperation. The test ban preceded this broader treaty, which also addressed nuclear proliferation and disarmament.
Moscow–Washington hotline: A direct communications link established between the United States and Soviet Union in 1963. The hotline and treaty were parallel steps toward managing the risks exposed by the 1962 crisis.
Underwater nuclear testing: Detonation of nuclear weapons beneath the surface of oceans, seas, or other waters. The treaty expressly prohibited underwater tests, including those that could spread radioactive contamination.