Nuclear Powers Sign the Limited Test Ban Treaty Summary

  • Last updated on November 10, 2022

The United States, the Soviet Union, and the United Kingdom signed a precedent-setting treaty that prohibited nuclear testing in particular environments and reduced radioactive pollution of the atmosphere. Underground testing, however, did not subside after the treaty, and it actually increased. Subsequent nuclear treaties would follow in this agreement’s footsteps.

Summary of Event

On August 5, 1963, the United States, the Soviet Union, and the United Kingdom signed the Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space, and Under Water, also known as the Limited Test Ban Treaty (LTBT) or the Partial Test Ban Treaty. The treaty was the result of several years and hundreds of arduous, complex, diplomatic negotiations throughout the late 1950’s and early 1960’s, and it had profound global political and ecological consequences. Limited Test Ban Treaty (1963) Nuclear weapons;testing U.S.-Soviet relations[U.S. Soviet relations];Cold War treaties and agreements Soviet-Western relations[Soviet Western relations];Cold War treaties and agreements Cold War;U.S.-Soviet treaties[U.S. Soviet treaties] Nuclear weapons;treaties [kw]Nuclear Powers Sign the Limited Test Ban Treaty (Aug. 5, 1963) [kw]Limited Test Ban Treaty, Nuclear Powers Sign the (Aug. 5, 1963) [kw]Treaty, Nuclear Powers Sign the Limited Test Ban (Aug. 5, 1963) Limited Test Ban Treaty (1963) Nuclear weapons;testing U.S.-Soviet relations[U.S. Soviet relations];Cold War treaties and agreements Soviet-Western relations[Soviet Western relations];Cold War treaties and agreements Cold War;U.S.-Soviet treaties[U.S. Soviet treaties] Nuclear weapons;treaties [g]Europe;Aug. 5, 1963: Nuclear Powers Sign the Limited Test Ban Treaty[07660] [g]Soviet Union;Aug. 5, 1963: Nuclear Powers Sign the Limited Test Ban Treaty[07660] [c]Cold War;Aug. 5, 1963: Nuclear Powers Sign the Limited Test Ban Treaty[07660] [c]Diplomacy and international relations;Aug. 5, 1963: Nuclear Powers Sign the Limited Test Ban Treaty[07660] [c]Environmental issues;Aug. 5, 1963: Nuclear Powers Sign the Limited Test Ban Treaty[07660] Kennedy, John F. [p]Kennedy, John F.;Cold War Khrushchev, Nikita S. [p]Khrushchev, Nikita S.;Cold War Harriman, William Averell

William Averell Harriman was the chief treaty negotiator for the United States, and Secretary of State Dean Rusk Rusk, Dean signed the agreement, which specifically precluded all nuclear tests in space, in Earth’s atmosphere, and underwater and barred nuclear testing in any environment where radioactive fallout could escape the territorial boundaries of the nation that conducted the nuclear explosion. The pact even prohibited nuclear testing designed for peaceful purposes. The treaty was an effort to eliminate ecological hazards and radioactive pollution, halt the proliferation of nuclear arms, and, ultimately, bring about comprehensive nuclear disarmament.

A nuclear test conducted by the U.S. Atomic Energy Commission (AEC) on March 1, 1954, at Bikini Atoll Bikini Atoll;nuclear bombing of Nuclear fallout Radioactive contamination in the Pacific Ocean had led to the radiation death of one individual and the illness of others aboard a Japanese fishing boat. The accident focused global attention on the serious ecological and human health risks of nuclear testing and radioactive fallout. As a result of the public outcry, several nations (including India) suggested plans for the elimination of all nuclear testing. The United States, the Soviet Union, and the United Kingdom continued atmospheric nuclear testing, however, and the nuclear arms race accelerated rapidly throughout the 1950’s. Adverse global public opinion intensified after Great Britain detonated its first hydrogen bomb in 1956 (the United States had exploded its first hydrogen bomb in 1952 and the Soviet Union exploded its first in 1953).

The year 1957 was a watershed for U.S. policies on nuclear testing and arms control. That year, the Soviet Union became the first nation to test an intercontinental ballistic missile Missiles;intercontinental ballistic (ICBM), as well as the first to introduce an orbiting satellite, Sputnik. Although the United States quickly responded with its own ICBM and satellite, its technological and military supremacy had been called into question. At the same time, however, the concept of a nuclear testing treaty became more attractive.

President Dwight D. Eisenhower’s Eisenhower, Dwight D. [p]Eisenhower, Dwight D.;nuclear technology position on a nuclear test ban ranged from resistance during his first term of office to enthusiastic support during his second. A nuclear scientist who had been appointed as liaison between the scientific community and Eisenhower’s staff convinced the administration that national security interests could be preserved with a test ban and that violations could be detected. The Soviet Union had already extended several proposals for a test ban treaty. In 1958, a U.S. counterproposal linked a test ban with specific verification processes, including frequent on-site inspections to detect potential nuclear tests; this proposal did not limit nuclear arms production. During the time of these open negotiations, the two countries respected a moratorium on nuclear testing. In 1960, however, negotiations collapsed as a result of intensified hostilities.

Even while serving as senator, John F. Kennedy had strongly rejected a renewal of U.S. testing during the 1958 moratorium. He subsequently made the test ban treaty a central issue of his 1960 presidential campaign and a cornerstone of his foreign policy during his presidency. Kennedy also supported the creation of a federal agency responsible for pursuing nuclear disarmament and investigating incidents of radioactive fallout. He created the Arms Control and Disarmament Agency Arms Control and Disarmament Agency, U.S. Nuclear weapons;disarmament on September 26, 1961.

The military, foreign policy, and scientific advisers on Kennedy’s staff agreed with his position on the test ban. In 1961, they designed a comprehensive arms control proposal titled Plan for General and Complete Disarmament in a Peaceful World Plan for General and Complete Disarmament in a Peaceful World , which called for a U.N. disarmament agency and an end to the global proliferation of nuclear arms. Throughout this period, Kennedy remained committed to a nuclear test ban treaty to reduce environmental radioactive contamination; he rejected linking such a treaty with the kind of conventional arms reduction desired by the Soviet Union.

Nuclear tests resumed after the Soviet Union’s atmospheric explosion of a 150-kiloton device on September 1, 1961. Two weeks later, the United States countered with a nuclear underground test of a 6-kiloton device. Although Kennedy was convinced that U.S. national security depended on continued atmospheric nuclear testing, he had reservations about the resumption of testing and monitored each test closely.

Contrary to Kennedy’s September 5 declaration that U.S. tests would be safe, it became known that the September 1 test had released radiation into the atmosphere. Yet another series of U.S. atmospheric tests, Operation Dominic, began on April 25, 1962, near Christmas Island in the Pacific Ocean. The tests conformed with U.S. guidelines that limited the explosion’s maximum cumulative yield to twenty megatons, but the operation failed to predict extensive atmospheric radiation resulting from a high-altitude test called Starfish. In the wake of these accidents, the Kennedy administration announced that ecological and human health issues stemming from radioactive fallout would be a major factor in any future nuclear testing decision.

President John F. Kennedy signs the Limited Test Ban Treaty.

(National Archives)

While many such policy statements in both the United States and the Soviet Union were no more than propaganda, there was outside pressure on both superpowers to address the ecological and health risks of atmospheric radioactive fallout. Growing public fear of the consequences of atmospheric nuclear explosions led to the organization of professional political interest groups such as Physicians for Social Responsibility. These organizations published information on the global health and environmental implications of weapons of mass destruction; such publications had great impact on public opinion, as did books such as John Hersey’s Hiroshima (1946). In 1962, a group of physicists established the Council for a Livable World, a lobbying association for disarmament, specifically for the U.S. Senate ratification of the Limited Test Ban Treaty (LTBT). A research study in 1962 to measure the health risks of radioactive fallout from nuclear tests indicated that high amounts of the nuclear element strontium 90 could be found in baby teeth.

A series of foreign relations crises in the early months of the Kennedy presidency created an international climate conducive to serious discussions about nuclear arms control and testing. During negotiations at the 1961 Geneva Conference, the United States and Great Britain declared themselves prepared to make concessions to the Soviet Union on the issue of verification (especially as regarded on-site inspections). In response, the Soviet Union in November of that year proposed a treaty to ban nuclear tests in space, in the atmosphere, and underwater and to establish a moratorium on underground tests. The United States had reservations, and the Geneva Conference concluded in January, 1962, without an agreement. Talks resumed in Geneva in April, and in November the United Nations ratified two resolutions calling for a nuclear test ban. In February, 1963, the Kennedy administration proposed a revised test ban that renounced the establishment of an independent global supervisory agency and further reduced the number of on-site inspections.

On July 15 a U.S. delegation led by Undersecretary of State Harriman initiated a series of quiet diplomatic talks in Moscow. Although the Kennedy administration sought a comprehensive test ban and disarmament treaty, U.S. representatives realized that only a limited pact would be feasible. The resulting treaty was narrowly focused and modest, but public opinion in the United States was strongly in favor of the proposed treaty for its expected effect on radioactive fallout. The LTBT was approved by the Senate on September 24 by an 80-19 vote. Kennedy ratified the treaty on October 7 and the ban took effect on October 10.


The Limited Test Ban Treaty was a landmark decision. The agreement set a positive precedent for a formal, substantive dialogue between the United States and the Soviet Union, and it significantly eased Cold War tensions. Moreover, the LTBT represented a fundamental first step toward a global policy of arms control and disarmament and set a precedent for subsequent nuclear treaties. The relative brevity of the agreement, which consisted of only five articles, was partly in consequence of its initial purpose as a transitional step.

The LTBT had no direct impact on underground nuclear testing, a serious source of radioactive discharge into the atmosphere. Although the treaty did not specifically address underground testing, it did forbid signatory nations from allowing radioactive fallout from such explosions to escape beyond the territory of the power conducting the test.

Although the LTBT was directly responsible for discouraging massive nuclear weapons testing, particularly in the atmosphere, it did not prevent the nuclear powers, primarily the United States and Soviet Union, from developing increasingly potent and sophisticated nuclear weapons. Indeed, by the time they ratified the treaty, the major parties had engaged in a range of nuclear tests that had led to the design of more powerful nuclear weapons. Furthermore, after the signing of the pact, the United States and the Soviet Union—as well as nontreaty countries such as France and China—significantly increased the number of nuclear tests they conducted. Nor did the treaty entirely deter global proliferation of nuclear capability; China became a nuclear power in 1964.

Violations of the LTBT by the United States and the Soviet Union were occasionally detected when radiation fallout drifted beyond the borders of the testing state. The LTBT’s verification procedures provided data even of atmospheric radiation from underground testing. After public disclosures of such abuses, the United States, unlike the Soviet Union, tried to reduce the fallout. Although the administrations that followed Kennedy’s showed significant shifts of policy, strategies, and priorities, most supported the concept of a comprehensive test ban.

The LTBT had a positive ecological impact, particularly on the atmosphere, where it led to reduced radioactive contamination. As a result, human health problems linked to nuclear testing and radioactive fallout substantially decreased. The environments covered by the Limited Test Ban Treaty were extended by the subsequent Outer Space Treaty of 1967 and Moon Treaty of 1979. The Comprehensive Nuclear-Test-Ban Treaty of 1996 prohibited all nuclear explosions in all environments. The United States, however, because it signed the treaty but did not ratify it, is not bound by the treaty’s stipulations. Limited Test Ban Treaty (1963) Nuclear weapons;testing U.S.-Soviet relations[U.S. Soviet relations];Cold War treaties and agreements Soviet-Western relations[Soviet Western relations];Cold War treaties and agreements Cold War;U.S.-Soviet treaties[U.S. Soviet treaties] Nuclear weapons;treaties

Further Reading
  • citation-type="booksimple"

    xlink:type="simple">Barton, John H., and Lawrence D. Weiler, eds. International Arms Control: Issues and Agreements. Stanford, Calif.: Stanford University Press, 1976. A comprehensive and detailed exposition of the issues of arms control and weapons testing from historical, intellectual, military, economic, and technological perspectives.
  • citation-type="booksimple"

    xlink:type="simple">Blacker, Colt D., and Gloria Duffy, eds. International Arms Control: Issues and Agreements. Rev. ed. Stanford, Calif: Stanford University Press, 1984. A substantive revision and update of the original edition, providing informative and helpful analyses of the SALT II and START agreements and with a discussion of the critical role of the LTBT.
  • citation-type="booksimple"

    xlink:type="simple">Hymans, Jacques E. C. The Psychology of Nuclear Proliferation: Identity, Emotions, and Foreign Policy. New York: Cambridge University Press, 2006. A unique examination of the links between foreign policy decisions, namely the choice to develop or not develop a nuclear weapons program, and a given leader’s understanding of his or her nation’s feelings and beliefs about nuclear weaponry. Makes clear that the decision to go nuclear—or not—is made not by some abstract policymaking entity but by “individual hearts.”
  • citation-type="booksimple"

    xlink:type="simple">Lepper, Mary Milling. Foreign Policy Formulation. Columbus, Ohio: Charles E. Merrill, 1971. Includes a useful case study of the political and public policy factors that influenced the development of the U.S. position on the LTBT.
  • citation-type="booksimple"

    xlink:type="simple">Ranger, Robin. Arms and Politics 1958-1978: Arms Control in a Changing Political Context. Toronto, Ont.: Gage, 1979. Sophisticated scholarly analysis of technical and political aspects of arms control, with interesting insights into the implications of the LTBT.
  • citation-type="booksimple"

    xlink:type="simple">Seaborg, Glenn T. Kennedy, Khrushchev, and the Test Ban. Berkeley: University of California Press, 1981. Lucid insights by the chair of the Atomic Energy Commission during the Kennedy administration on the complicated diplomatic negotiations of the LTBT. Useful analysis of the conflicting interests and pressures of the Atomic Energy Commission, State Department, and Defense Department.
  • citation-type="booksimple"

    xlink:type="simple">United Nations Treaty Collection. Treaty Handbook. Available at An excellent resource on the international treaty process. An online handbook provided by the Treaty Section of the U.N. Office of Legal Affairs.

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