The Treaty on the Non-Proliferation of Nuclear Weapons (NPT) is an international treaty that serves as the cornerstone of the global nuclear non-proliferation regime. It was negotiated between 1965 and 1968 and entered into force on 5 March 1970. The treaty was created to solve the problem of potential widespread nuclear proliferation, which was predicted to result in 25 to 30 nuclear weapon states.
The NPT works through three pillars: non-proliferation, disarmament, and the peaceful use of nuclear energy. Article I obligates the five recognized Nuclear Weapon States (NWS)—those that tested a device before 1 January 1967: the US, Russia, UK, France, and China—not to transfer nuclear weapons or assist non-nuclear-weapon states (NNWS) in acquiring them. In return, Article II requires NNWS to forgo the manufacture or acquisition of nuclear weapons. To verify this, Article III mandates that NNWS accept comprehensive safeguards agreements with the International Atomic Energy Agency (IAEA) to prevent the diversion of nuclear material from peaceful uses. The treaty also affirms the "inalienable right" of all parties to develop nuclear energy for peaceful purposes under Article IV. Crucially, Article VI commits all parties, particularly the NWS, to pursue good-faith negotiations toward nuclear disarmament.
The treaty was originally set for a 25-year duration but was extended indefinitely in 1995. While the core articles remain, this indefinite extension was the most significant change. The NPT regime connects to the IAEA for verification and the Nuclear Suppliers Group for export controls. India, along with Israel, Pakistan, and South Sudan, is a non-party to the NPT.