The Treaty on the Non-Proliferation of Nuclear Weapons (NPT) is an international treaty and the cornerstone of the global nuclear non-proliferation regime. It was negotiated between 1965 and 1968 by the Eighteen Nation Committee on Disarmament and was opened for signature on July 1, 1968, entering into force on March 5, 1970. The treaty was created to solve the problem of mounting international concern over the spread of nuclear weapons technology, which threatened to create up to 25–30 nuclear weapon states.
The NPT works by establishing a "grand bargain" based on three pillars: non-proliferation, disarmament, and the peaceful use of nuclear energy. It divides signatories into nuclear-weapon states (NWS)—those that manufactured and detonated a nuclear explosive device prior to January 1, 1967 (China, France, Russia, the United Kingdom, and the United States)—and non-nuclear-weapon states (NNWS). NWS agree, under Article I, not to transfer nuclear weapons or technology, and under Article VI, to pursue negotiations in good faith toward nuclear disarmament. NNWS pledge, under Article II, not to acquire nuclear weapons and, under Article III, to accept comprehensive safeguards and inspections by the International Atomic Energy Agency (IAEA) to verify compliance. Article IV promotes the exchange of technology for the peaceful use of nuclear energy.
The treaty is connected to the IAEA, which monitors the civil nuclear programs of NNWS. It is also related to the Comprehensive Test Ban Treaty (CTBT), which has rendered Article V (on peaceful nuclear explosions) practically obsolete. The most significant change to the treaty was at the 1995 Review Conference, which extended the NPT indefinitely, replacing its original 25-year duration. India, along with Pakistan, Israel, and South Sudan, is not a party to the NPT, viewing it as a discriminatory instrument that divides the world into "nuclear haves" and "nuclear have-nots".