Treaty on the Non-Proliferation of Nuclear Weapons

More often known as the Nuclear Nonproliferation Treaty (NPT), this treaty is correctly named the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) With the first signatures in 1968, the Treaty became  active in 1970. A total of 187 parties have joined the Treaty, including the five nuclear-weapon States. An active UN organization, the International Atomic Energy Agency, works both with enforcement and the promotion of peaceful use of nuclear weapons. Its actual language is reviewed at five-year intervals.

After the ratification, states were only allowed to join the five nations, China, France, Soviet Union/Russia, United Kingdom, and United States that were "declaratory" and announced they had a nuclear arsenal they would keep. New signatories were expected to be "non-declaratory" and renounce having their own nuclear weapons. As a result, several nations that either have or are strongly suspected to have nuclear weapons have refused to sign as "non-declaratory" states: India, Israel, North Korea and Pakistan. One special case is South Africa, which built nuclear weapons but disarmed itself under secret international monitoring, and is a nondeclaratory signatory.