nuclear disarmament, the reduction and limitation of the various nuclear weapons in the military forces of the world's nations. The atomic bombs dropped (1945) on Japan by the United States in World War II demonstrated the overwhelming destructive potential of nuclear weapons and the threat to humanity posed by the possibility of nuclear war and led to calls for controls on or elimination of such weapons.
Some of the scientists who helped make the bomb started the Union of Concerned Scientists, and since then many public groups have formed to campaign for disarmament, including the Campaign for Nuclear Disarmament (CND) in Great Britain, SANE and the Nuclear Freeze in the United States, and the worldwide Physicians for Social Responsibility. In addition, many local antiwar, ecological, and women's groups have focused on nuclear issues. Disarmament advocates have used political campaigns, mass rallies, blockades of facilities where weapons are manufactured or stored, and even attacks on nuclear weapons themselves, called "ploughshare actions." Disarmament groups have long opposed nuclear testing, beginning with the protests leading up to the Moscow Agreement of 1963, a partial test ban. More recently, the international ecological group Greenpeace tried to disrupt French nuclear testing in the Pacific, and there were coordinated protest campaigns against testing in Kazakhstan and in Nevada.
Official efforts at arms control have made some progress, but only very slowly. The first resolution (1946) of the General Assembly of the United Nations set up an Atomic Energy Commission to make proposals for the peaceful uses of atomic energy and for the elimination of weapons of mass destruction. The commission concentrated debate on the Baruch Plan for an international agency to control atomic power and weapons and passed it, but the plan was vetoed by the USSR in the Security Council. As the cold war progressed, the commission reached an impasse (1948). With the proliferation of nuclear weapons, concern over the situation became more acute.
In 1952 a UN Disarmament Commission was formed under the Security Council. It became the repository for all disarmament proposals under UN auspices. In 1953 a commission subcommittee was set up, consisting of Canada, France, Great Britain, the United States, and the USSR. In this subcommittee, which met intermittently from 1954 to 1957, there was basic disagreement between East and West. The West held that an international control system and on-site inspection must be developed before disarmament could proceed; the USSR stated that the Western position would result in inspection without disarmament and proposed instead an immediate ban on nuclear weapons, without inspection but with possible later, but unspecified, controls. Conferences among the United States, Great Britain, and the Soviet Union on the formulation of a treaty to ban nuclear testing began in Geneva in 1958. The same year these three powers agreed to suspend nuclear testing for one year. The voluntary moratorium continued until it was broken by the Soviet resumption of testing (1961).
The UN Disarmament Commission, expanded (1958) to include all members of the United Nations, was reduced in 1962 to 18 members. Soon afterward, France withdrew. In 1963 the United States, Great Britain, and the Soviet Union reached the Moscow Agreement, which banned testing in the atmosphere, in outer space, and underwater. Other discussions were conducted simultaneously by the 18-member UN Disarmament Commission. No agreement was reached on arms limitation, although the Soviet Union and the United States moved closer together on the issue of the proliferation of nuclear weapons. The two countries proposed (1968) to the commission a 25-year nonproliferation agreement that was later approved by the UN General Assembly and took effect in 1970; it was made permament in 1995. By the end of the century the treaty had been ratified by all nations save Cuba, Israel, Pakistan, and India. North Korea threatened to withdraw in the 1990s and did so in 2003. Pakistan and India have tested nuclear weapons, North Korea has conducted a subkiloton nuclear test, and Israel is believed to have nuclear weapons. Argentina, Brazil, Iran, Iraq, Libya, and South Africa are known to have or are suspected of having attempted to develop nuclear weapons; South Africa actually produced a small nuclear arsenal but later disarmed.
A comprehensive test ban treaty was approved by the UN General Assembly and signed in 1996; over 180 nations have now signed. The treaty prohibits all nuclear testing, establishes a worldwide network of monitoring stations, and allows for inspections of suspicious sites. Conservative opposition to the treaty in the United States led the Senate to reject ratification in 1999. Russia ratified it in 2000, but China has not yet done so.
The Soviet Union and the United States began Strategic Arms Limitation Talks (SALT) in the late 1960s, and in 1972 agreed to limit antiballistic missiles (ABMs) and reached an interim accord limiting intercontinental ballistic missiles (ICBMs). Another interim SALT agreement was reached in Nov., 1974, that limited ballistic missile launchers. SALT II, which banned new ICBMs and limited other delivery vehicles, was signed in 1979. It was never ratified, but both countries announced they would adhere to it.
In 1982 the United States and Soviet Union began a new set of negotiations, called START (Strategic Arms Reduction Talks). In 1987, President Reagan and Soviet leader Mikhail Gorbachev signed the INF treaty to eliminate intermediate-range nuclear forces, and a START treaty, signed by President George H. W. Bush and Gorbachev in 1991, called for additional reductions in U.S. and Soviet nuclear arsenals and on-site inspections. In response to increasing Soviet political instability, Bush announced (1991) the elimination of most U.S. tactical nuclear arms, took strategic bombers off alert status, and called for further reductions in ballistic missiles.
With the USSR's disintegration, its nuclear arms passed to Belarus, Kazakhstan, Russia, and Ukraine. The republics pledged to abide by existing treaties and remove outlying weapons to Russia for destruction. In 1993, Bush and Russian president Yeltsin signed a START II treaty that called for cutting nuclear warheads by two thirds by 2003 and eliminating those weapons most likely to be used in a first strike. Ukraine, fearing Russian domination, did not ratify START and the 1970 nonproliferation treaty until 1994, but by 1996 the nuclear arsenals of Belarus, Kazakstan, and Ukraine had been dismantled.
In 1997, Yeltsin and U.S. president Bill Clinton set a goal of further reducing the number of each nation's warheads to 2,500 or less, less than half that permitted under START II. President George W. Bush, regarding earlier arms agreements and the need for them as cold war relics, in 2001 agreed with Russian president Putin to reduce the number of warheads over the next decade to roughly two thirds that called for in START II, while at the same time essentially abandoning that agreement (which was still unratified by the United States) and its restrictions on the types of weapons permitted. This agreement was formalized in the May, 2002, Moscow Treaty. However, under the treaty, both nations were allowed to store the weapons that they removed from deployment, and the accord was criticized for its lack of a mechanism to verify compliance. Following the U.S. abandonment of the ABM treaty (see below), Russia announced that it would no longer be bound by START II. In 2009, however, the United States and Russia agreed in outline to further nuclear weapons cuts under a new treaty intended to replace START I before its expiration in Dec., 2009. Negotiations, however, continued past the treaty's lapse (both nations continued to observe START I). The New START treaty, signed in Apr., 2010, established lower limits on deployed warheads.
In 1983, President Reagan proposed the development of a U.S. space-based defensive system to act as a shield against a missile attack. The Strategic Defense Initiative, or "Star Wars" as it was popularly known, was ultimately abandoned by the United States, but a more limited missile-defense system using ground-based missiles to provide protection against an accidental launching of a ballistic missile or against a missile attack from a "rogue" nation was proposed in 1991 by President G. H. W. Bush. Such a system would contravene the 1972 ABM treaty and was objected to by Russia, but development and testing proceeded during the 1990s. In 2001, President George W. Bush proposed accelerating and expanding the development and deployment of the system and called for the ABM treaty to be replaced by a new "framework" that would permit such defenses. The United States announced that it would withdraw from the ABM treaty in Dec., 2001, and officially withdrew in June, 2002.
See W. Epstein and B. Feld, New Directions in Disarmament (1981); J. Schell, The Abolition (1986); M. Thee, Arms and Disarmament (1987); P. Taubman, The Partnership: Five Cold Warriors and Their Quest to Ban the Bomb (2011).