Limited Test Ban Treaty (LTBT)

THE TREATY: International agreement to halt nuclear test explosions in the atmosphere, under the sea, and in outer space

DATE: Opened for signature on August 5, 1963

The Limited Test Ban Treaty opened a dialogue between the United States and the Soviet Union that helped to ease Cold War tensions. It represented a fundamental step toward a global policy of arms control and disarmament, and it also had a positive ecological impact, particularly in the atmosphere, where it led to reduced radioactive contamination.

The atomic bomb was developed by the United States during World War II. The first test explosion of the bomb was carried out in July 1945 in the desert of New Mexico. Less than one month later, the US military used atomic bombs to destroy the Japanese cities of Hiroshima and Nagasaki, bringing the war to an end. Other countries soon developed their own bomb technology. The Soviet Union exploded an atomic bomb in 1949, followed by Great Britain in 1952 and France in 1960. During the 1950s, both the United States and the Soviet Union embarked on military programs to build intimidating nuclear arsenals.

In 1954, the United States detonated a powerful hydrogen bomb at Bikini Atoll in the South Pacific. A Japanese fishing boat that was some 160 kilometers (100 miles) away from the blast was contaminated by radioactive when the wind unexpectedly shifted, and the twenty-three sailors aboard suffered sickness. This incident led to worldwide protests against further nuclear weapons testing. Antinuclear rallies in the United States and Europe mobilized public opinion against the escalating arms race. In 1958, US president Dwight D. Eisenhower and Soviet premier Nikita Khrushchev agreed to a moratorium on nuclear weapons testing in the atmosphere. It lasted for almost three years, until renewed tensions between the two superpowers—caused by the U-2 spy plane incident and the Berlin Crisis of 1961—led both countries to resume testing. The most powerful bomb in history was a 58-megaton nuclear device detonated by the Soviet Union in October 1961.

Nuclear explosions in the atmosphere create radioactive particles that are spread around the world by prevailing winds and return to earth with precipitation. Radioactive cesium and iodine are two notably harmful materials that have contaminated grass pastures, causing grazing cows to produce radioactive milk. A study of baby teeth in the early 1960s showed the presence of radioactivity, primarily from milk consumption. The amount of was not enough to cause radiation sickness, but even small doses of radiation have a statistical probability of increasing the likelihood of the development of cancers. Researchers with the Brookings Institution estimated that, worldwide, the testing of atomic bombs resulted in at least seventy thousand more cases of cancer than would otherwise have occurred.

The Cuban Missile Crisis of 1962 brought the world to the brink of nuclear war. This confrontation between the United States and the Soviet Union led to the mutual realization that the nuclear arms race could escalate into annihilation for both sides. Subsequent negotiations resulted in the signing of the Limited Test Ban Treaty on August 5, 1963, by the United States, the United Kingdom, and the Soviet Union. The treaty, which went into effect on October 10, 1963, prohibited the signatory nations from conducting nuclear weapons tests in the atmosphere, under the ocean, and in outer space; it still permitted underground explosions, however.

The agreement opened a dialogue between the United States and the Soviet Union and significantly eased Cold War tensions. It represented a fundamental step toward a global policy of arms control and disarmament. The treaty also had a positive ecological impact, particularly in the atmosphere, where it led to reduced radioactive contamination; as a result, human health problems linked with nuclear testing and radioactive fallout decreased substantially.

By 1992, 125 countries had signed and become parties to the Limited Test Ban Treaty; by 2008, the number of nations that had signed or acceded to the treaty had risen to 133, although some of them had yet to ratify it. A voluntary ban on underground explosions took effect in 1992, and negotiations for the Comprehensive Nuclear-Test-Ban Treaty were initiated at the United Nations in the late 1990s; that treaty was adopted by the General Assembly of the United Nations in September 1996, but still was not ratified by the 2020s. In the meantime, nuclear testing continued as France exploded bombs at the Mururoa atoll in the Pacific Ocean as late as 1995, and as Pakistan and India conducted underground nuclear testing in 1998.

In the twenty-first century, only North Korea was known to have conducted underground nuclear testing.

Bibliography

Barrett, Scott. “International Environmental Agreements.” In Environment and Statecraft: The Strategy of Environmental Treaty-Making. New York: Oxford University Press, 2003.

Diaz-Maurin, Francois. "Introduction: Nuclear Testing in the 21st Century--Legacies, Tensions, and Risks." Bulletin of the Atomic Scientists, 7 Mar. 2024, thebulletin.org/premium/2024-03/introduction-nuclear-testing-in-the-21st-century-legacies-tensions-and-risks/. Accessed 18 July 2024.

Hansen, Keith A. “Early Efforts to Limit Nuclear Testing.” In The Comprehensive Nuclear Test Ban Treaty: An Insider’s Perspective. Stanford, Calif.: Stanford University Press, 2006.

"Test Ban Treaty (1963)." National Archives, 8 Feb. 2022, www.archives.gov/milestone-documents/test-ban-treaty. Accessed 18 July 2024.