Nuclear test ban

The Comprehensive Test Ban Treaty (CTBT), which prohibits all nuclear explosions either for military or "peaceful" purposes, was adopted by the United Nations General Assembly in September 1996. Although disputes remain in some countries over the ratification of the treaty, the adoption of the text by the General Assembly marks the culmination of several decades of intermittent negotiation aimed at the worldwide prohibition of nuclear explosions within the United Nations nuclear nonproliferation framework. The CTBT aims at preventing the development and proliferation of nuclear weapons and is viewed by the United Nations as an important step toward eventual nuclear disarmament.

President Dwight D. Eisenhower first suggested a ban on atmospheric testing in 1955, but it was not until August 1963, in the aftermath of the 1962 superpower showdown over the stationing of nuclear-capable missiles in Cuba, that the United States and the U.S.S.R. agreed to a Partial Test Ban Treaty (PTBT). This agreement banned all atmospheric tests of nuclear weapons, but allowed both parties to set off explosions in the more frequently-used underground tests. With both superpowers concerned about issues of sovereignty and espionage, the PTBT limited procedures for verification of compliance to what were called "national technical means," which consisted mainly of satellite, communications, and long-distance seismic monitoring. While the PTBT's overall impact on arms control is generally thought to have been negligible, it did serve to prevent a great deal of pollution of the atmosphere and the Earth's surface by plutonium and other radioactive substances.

In 1974, the PTBT was supplemented by the signing of a Threshold Test Ban Treaty (TTBT) that limited the explosive yield of underground nuclear tests. Initially, the TTBT also relied on national technical means for verification. But in 1990, the original protocol was replaced with a new agreement on verification means that allowed for on-site inspections and in-country seismic monitoring.

Fourteen years after the adoption of the PTBT, the United States, U.S.S.R., and United Kingdom convened trilateral talks aimed at achieving a comprehensive test ban. Some limited progress was made toward resolving several points of disagreement, but in general the parties achieved few tangible results in these negotiations. This lack of success combined with a general toughening of United States policy towards the U.S.S.R. after the 1980 elections to all but end discussion of a test ban treaty.

Against the wishes of both the United States and the United Kingdom, a series of amendments was suggested in January 1991, under the authority of the existing treaties' revision procedures. A conference of the nuclear powers was convened to consider the proposed amendments. These negotiations were inconclusive, but they did signal considerable international interest in a comprehensive ban. Political momentum toward this end was given a boost in 1992, when Russia, France, and the United States declared a nine-month moratorium on all testing. In doing so, the United States reversed official doctrine introduced in the 1980s, which held that testing via explosions was a necessary component of national security. The radical geopolitical changes associated with the disintegration of the U.S.S.R. also played a role in changing the climate of negotiations. As a result, the 1994 Conference on Disarmament created a committee with a mandate to establish a framework for a comprehensive ban. By extending its own moratorium on nuclear tests, the Clinton Administration signaled its willingness to sign the resulting CTBT, giving the final process of negotiation an important boost.

Technological and political developments, however, are already raising new issues for arms control experts and negotiators. Advances in communications and surveillance technology aid the verification of compliance. But advances in nuclear physics and weapons technology, such as the advent of so-called micro-nukes and hydronuclear tests with greatly reduced yields, make the very definition of nuclear testing problematic. Several countries, especially India and Pakistan, have expressed strong misgivings about the CTBT. Although the United States strongly supports the treaty on an official level, substantial and deep-rooted opposition to the CTBT persists, including some notable critics among those charged with oversight of its huge nuclear arsenal. Opponents of the treaty argue that limited testing is necessary for checking the safety and reliability of existing nuclear warheads and for maintaining the credibility of the nuclear deterrent.

[Lawrence J. Biskowski ]