Page 1: Summary of the Treaty's History
Five decades of struggle to end nuclear testing
The struggle to end nuclear testing is six decades old. Back in 1954, nine years after the "Trinity" test － the word’s first nuclear explosion, conducted in Alamogordo, New Mexico, United States, on 16 July 1945 － the Prime Minister of India, Jawaharlal Nehru, advocated a “standstill agreement” on nuclear testing.
1963: Partial Test Ban Treaty (PTBT)
By the mid-1950s, the United States and the Soviet Union started conducting high-yield thermonuclear weapon testing in the atmosphere. The radioactive fallout from these tests gave rise to increasing international criticism, leading to the first victory for test-ban advocates: the Partial Nuclear Test-Ban Treaty (PTBT) signed in 1963 banned nuclear testing in outer space, the atmosphere and under water, but not underground. While the PTBT reduced radioactive fallout, nuclear weapons testing not only continued - albeit underground - but also increased greatly in numbers (see graph).
1968: The Nuclear Non-Proliferation Treaty
Another important milestone was reached in 1968 with the adoption of the Nuclear Non-Proliferation Treaty (NPT), which laid the foundation of the nuclear non-proliferation and disarmament regime. A comprehensive ban on nuclear testing was discussed, but not agreed upon. However, it features in the NPT’s preamble and was promised by the nuclear weapon States during the 1995 and 2000 NPT Review Conferences.
The Group of Scientific Experts (GSE)
Scientists from different countries have conducted joint research into monitoring technologies and data analysis methods for the verification of a comprehensive test ban since 1976 in the so-called Group of Scientific Experts (GSE). Only three decades later, however, the political climate was ripe: In 1994, the United Nations’ disarmament body, the Conference on Disarmament (CD) in Geneva, began formal negotiations on the Comprehensive Nuclear-Test-Ban Treaty (CTBT), which lasted until 1996.