Limited Test Ban Treaty

The Limited Test Ban Treaty (LTBT), sometimes called the Partial Test Ban Treaty, was first signed in 1963 by the United States, the Union of Soviet Socialist Republics (U.S.S.R.), and the United Kingdom. It prohibits the testing of NUCLEAR WEAPONS in the atmosphere, underwater, or in space. As the first significant ARMS CONTROL agreement of the COLD WAR, the LTBT set an important precedent for future arms negotiations.

The LTBT followed quickly on the heels of the 1962 CUBAN MISSILE CRISIS, in which the United States and the U.S.S.R. came to the brink of war over the Soviet Union's placement of missiles in Cuba. Alarmed at the prospect of nuclear war, President JOHN F. KENNEDY, of the United States, and Premier Nikita Khrushchev, of the Soviet Union, agreed to begin serious arms control negotiations. The LTBT was one of the first fruits of these negotiations. Proponents of the treaty claimed that it would prevent contamination of the environment by radioactive fallout from nuclear testing, slow down the arms race, and inhibit the spread of nuclear weapons to other countries.

President Kennedy ratifies the Limited Test Ban Treaty on October 7, 1963. Looking on are Sen. John Pastore, W. Averell Harriman, Sen. James Fulbright, Dean Rusk, Sen. George Aiken, Sen. Hubert Humphrey, Sen. Everett Dirksen, William Foster, Sen. Howard Cannon, and Sen. Leverett Saltonstall.
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Although Kennedy hailed the LTBT as a significant achievement of his presidency, he was disappointed that he could not secure a comprehensive test ban treaty, which would have banned all forms of nuclear testing. Lacking such a ban, the superpowers and other countries with nuclear capability continued to test nuclear weapons underground. However, article 1, section b, of the LTBT pledges that each of its signatory countries will seek "a treaty resulting in the permanent banning of all nuclear test explosions, including all such explosions underground." By 1973, a total of 106 countries had signed the LTBT, and by 1992, that number had grown to 119.

Later test ban treaties have included the Threshold Test Ban Treaty of 1974, which prohibited nuclear tests of more than 150 kilotons (the explosive force of 150,000 tons of TNT), and the Peaceful Nuclear Explosions Treaty of 1976. Although a comprehensive test ban agreement has not yet been reached, the nuclear powers and many nations without nuclear capabilities continue to negotiate the provisions of such a treaty.