Nuclear Nonproliferation Treaty (NPT)
a binding international agreement that seeks to prevent the spread of nuclear weapons technologies, further the goal of nuclear disarmament, and promote cooperation in the peaceful uses of nuclear energy. Entered into force in 1970, the NPT prohibits countries that did not have nuclear weapons at the time from ever developing them. The International Atomic Energy Agency (IAEA) is tasked with verifying compliance by the treaty’s 190 state signatories. Although North Korea ratified the NPT in 1985, it withdrew from the treaty in 2003 after the IAEA accused the country of illicit nuclear activities.