The Treaty on the Non-Proliferation of Nuclear Weapons (NPT) is one of the foundations of the global nuclear nonproliferation regime.  The treaty entered into force 1970 and is nearly universal with close to 190 parties, and only India, Israel, and Pakistan remain non-parties (North Korea withdrew in early 2003).  The NPT defines nuclear-weapon states as states that manufactured or exploded a nuclear weapon prior to January 1, 1967, the United States, Russia, China, France, and the United Kingdom or the “P-5”.  All other states are defined by the treaty as non-nuclear-weapon states.  The NPT remains the only global legal instrument in which:

• Nuclear-weapon states parties pledge not to transfer nuclear weapons or other nuclear explosive devices to any recipient whatsoever; nor to assist in any way any non-nuclear-weapon states to manufacture or acquire nuclear weapons or other nuclear explosive devices (Article I);
• Non-nuclear-weapon states parties pledge not to manufacture or acquire nuclear weapons or other nuclear explosive devices (Article II);
• Non-nuclear-weapon states parties accept as mandatory International Atomic Energy Agency safeguards over any source or special fissionable materials within their territory or jurisdiction (Article III);
• All parties undertake to facilitate cooperation in and have the right to participate in the peaceful uses of nuclear energy (Article IV) in conformance with Articles I and II of the Treaty; and
• All parties pledge to pursue negotiations in good faith on effective measures related to nuclear disarmament and on general and complete disarmament.  (Article VI).

NPT Article VIII allows for a conference every five years if a majority of parties so desire to review the operation of the treaty with a view to assuring that the purposes of the preamble and provisions of the treaty are being realized.  They have done so every five years since 1975.  The Preparatory Committee for the Review Conference  now meets in the three years prior to the Review Conference to make procedural arrangements and discuss matters of substance related to treaty implementation.  The 1995 NPT Review and Extension Conference indefinitely extended the NPT.

For more information on the treaty, click here.