The Treaty on the Non-Proliferation of Nuclear Weapons, commonly known as the Non-Proliferation Treaty or NPT, is an international treaty whose objective is to prevent the spread of nuclear weapons and weapons technology, to promote cooperation in the peaceful uses of nuclear energy, and to further the goal of achieving nuclear disarmament and general and complete disarmament.
Opened for signature in 1968, the treaty entered into force in 1970.
As required by the text, after twenty-five years, NPT Parties met in May 1995 and agreed to extend the treaty indefinitely.
More countries have adhered to the NPT than any other arms limitation and disarmament agreement, a testament to the treaty’s significance.
At present, 191 states have adhered to the treaty, though North Korea, which acceded in 1985 but never came into compliance, announced its withdrawal from the NPT in 2003, following detonation of nuclear devices in violation of core obligations.
Four UN member states have never accepted the NPT, three of which are thought to possess nuclear weapons: India, Israel, and Pakistan. In addition, South Sudan, founded in 2011, has not joined.