Treaty on the Non-Proliferation of Nuclear Weapons

The Treaty on the Non-Proliferation of Nuclear Weapons, commonly the Non-Proliferation Treaty or NPT, is an international treaty aiming to prevent the spread of nuclear weapons and weapons technology, promote cooperation in the peaceful use of nuclear energy, and further the goal of nuclear and general disarmament. Negotiated between 1965 and 1968 by the Eighteen Nation Committee on Disarmament, a United Nations-sponsored body in Geneva, it was opened for signature in 1968, entered into force in 1970, and was extended indefinitely by its parties in May 1995. The treaty defines nuclear-weapon states as those that built and tested a nuclear device before 1967, namely the United States, Russia, the United Kingdom, France and China; as of August 2016, 191 states were party to the treaty, though North Korea withdrew in 2003 and India, Israel and Pakistan have never joined.