Nuclear Non-Proliferation Treaty

The Treaty on the Non-Proliferation of Nuclear Weapons opened for signature in London, Moscow and Washington on July 1, 1968, and entered into force on March 5, 1970. Under it, states without nuclear weapons promise never to acquire them and accept inspections by the International Atomic Energy Agency (IAEA). The five states that had tested a bomb before 1967 (the United States, Soviet Union, United Kingdom, France and China) are recognized as nuclear-weapon states and promise, in Article VI, to pursue disarmament in good faith. All parties may use nuclear energy for peaceful purposes.¹

By the early 1960s the nuclear club was growing: the Soviets exploded a bomb in 1949, Britain in 1952, France in 1960 and China in 1964. John F. Kennedy warned in 1963 that there might be 15 to 25 nuclear states by the 1970s. The Cuban Missile Crisis of 1962 and the 1963 partial test ban convinced Washington and Moscow that cooperation was possible and necessary. Ireland, led by Foreign Minister Frank Aiken, pushed a UN resolution that started the talks, and the US and USSR drafted the treaty text together despite their rivalry.¹

The treaty was extended indefinitely in 1995 and has about 190 parties, among the most widely joined arms-control agreements. Its record is mixed. India, Pakistan and Israel never joined, and North Korea left in 2003 and tested weapons. Nine states now have nuclear weapons, far fewer than predicted in the 1960s. Yet South Africa, Ukraine, Belarus and Kazakhstan gave up weapons and joined, and the five original nuclear states have cut stockpiles from their peaks of around 70,000 warheads in 1986, though critics say they have not met the disarmament promise.¹