LTBT 63

negotiated  
ratified  10 October 1963
countries involved  131

Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space and under Water


Also known as The Limited Test Ban Treaty (LTBT), Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space and under Water was a trilateral agreement between the U.S., the U.S.S.R., and the U.K., which prohibited nuclear weapons tests and any other nuclear explosions in the atmosphere, in outer space, and under water. Although the Treaty does not ban underground tests, it does prohibit nuclear explosions in this environment if they cause radioactive debris to be present outside the territorial limits of the state under whose jurisdiction or control the explosions were conducted. Efforts to achieve a test ban agreement had extended over eight years. They involved complex technical problems of verification and difficulties of strong differences in approach to arms control and security. The uneven progress of the negotiations reflected the difficulties of East-West political relationships. Since 1963, an additional 113 countries have signed the Treaty. The Treaty entered into force October 10, 1963 and is of unlimited duration.

involved countries