Partial Nuclear Test Ban Treaty





The Limited Test Ban Treaty (LTBT) is a treaty prohibiting all test detonations of nuclear weapons except underground. It was developed both to slow the arms race (nuclear testing was, at the time, necessary for continued developments in nuclear weapons), and to stop the excessive release of nuclear fallout into the planet's atmosphere. The Treaty was signed and ratified by the governments of the Soviet Union, the United Kingdom, and the United States during the autumn of 1963.

It is officially known as the treaty banning nuclear weapon tests in the atmosphere, in outer space and under water, but is often abbreviated as the Partial Test Ban Treaty (PTBT), Limited Test Ban Treaty (LTBT), or Nuclear Test Ban Treaty (NTBT) – although the latter also refers to the Comprehensive Test Ban Treaty. The Treaty was signed by the governments of the U.S.S.R. (represented by Andrei Gromyko), the United Kingdom (represented by Alec Douglas-Home), and the United States (represented by Dean Rusk), named the "Original Parties", in Moscow on August 5, 1963, before being opened for signature by other countries. The Treaty of Moscow was ratified by the U.S. Senate on September 24, 1963, by a vote of 80 to 19. The treaty went into effect on October 10, 1963.

Background
Much of the initiative for the treaty had its focus in what was the rising concern about radioactive fallout as a result of nuclear weapons testing underwater, in the atmosphere, and on the ground's surface, on the part of the nuclear powers. These concerns became more pronounced after the United States successfully tested a hydrogen bomb and a thermonuclear device with the power of eight megatons of TNT in November 1952, and 15 megatons later on, and when the U.S.S.R. detonated a 60-megaton nuclear warhead, deliverable by a bomber, in October 1961.

Negotiations
Initially, the Soviet Union proposed a testing ban along with a disarmament agreement dealing with both conventional and nuclear weapon systems. The Western nuclear powers and the Soviet Union traded positions on this issue over the course of negotiations in the 1950s through offers and counteroffers proposed under the aegis of the United Nations Disarmament Commission. It was only later during 1959 and into the early 1960s that the United States, the United Kingdom, and the Soviet Union agreed to detach a general agreement on nuclear disarmament from a ban on nuclear weapons testing.

The Soviet Union, however, only agreed in principle to a testing ban with no verification regime or protocols. It was over what measures and the method by which they could be effectively carried out that caused much of the deadlock in the latter half of 1961 over a test ban agreement. The problem of detecting underground tests – that is, distinguishing it from an earthquake – proved to be particularly troublesome. Therefore, the United States and United Kingdom insisted on intrusive, inspection-based control systems as a means to verify compliance. On the other hand, the U.S.S.R. held the position that surveillance and seismic detection equipment operated from outside the boundaries of any signatory was adequate to verify compliance. The Western Powers thought that any agreement not subject to a control system rigorous enough to verify compliance would set a bad precedent in nuclear arms control for future agreements.

In June, 1963, President Kennedy dedicated what he would call one of the most important speeches of his life, at American University's commencement ceremonies, to making his case for the treaty. Deadlock ensued until early July, 1963, when Premier Khrushchev signaled his willingness to agree to a ban that would exclude underground testing. In effect, this meant the Soviet Union would agree to a test ban in the atmosphere, outer space, and under water environments. This was the position that the Western Powers had long favored as an alternative to a more comprehensive (underground environment) ban. This opened an opportunity for a three-power meeting among the United States, the United Kingdom, and the Soviet Union on July 15, 1963, in Moscow. The negotiations in Moscow, reflecting the long deliberations that had gone on for nearly a decade, took relatively little time as the treaty was signed by representatives of the three governments only 21 days later.

Signatories


Most countries have signed and ratified the treaty. Countries known to have tested nuclear weapons but which have not signed the treaty are China, France and North Korea.

Leaks of nuclear fallout
The provisions of the treaty eliminate the possibility of space, underwater and atmospheric testing. All testing was to be driven underground, just so long as the radioactivity did not go beyond the national border of the testing country. Both the Soviet Union and the United States subsequently performed what are known today as cratering shots intended to breach the surface but were carried on the official books as underground shots. Peaceful use test explosions are also banned, due to the difficulty in distinguishing weapons testing from purely scientific ones.

The most noteworthy violation of the Partial Nuclear Test Ban Treaty took place at the Chagan nuclear test in the Soviet Union, carried out on January 15, 1965. The charge was powerful enough that some fallout rained upon Japan, and both Japan and the United States complained, but the complaints were eventually dropped, and the problem was ignored by the foreign governments.

Both the United States nuclear test series and the Soviet Union's nuclear test series fired several devices in the 60s which were intentionally shallowly placed, intending cratering effects. None were the size of Chagan, and no fallout in other countries was detected from them.

The other accidental releases of fallout during nuclear testing have included the Baneberry nuclear test in 1970, carried out by the United States in Nevada. The dangerous effects of its radioactive fallout were soon described as one of the "world's worst nuclear disasters" by TIME magazine.