1954 India first proposes an international test ban treaty.
1959-60 Moratorium on testing implemented by the US, UK, and USSR.
1963 Partial Test Ban Treaty signed by the same three powers bans tests in the atmosphere, under water, and in outer space; the signatories agree to work towards a ban on underground tests.
1970 Non Proliferation Treaty commits the nuclear powers to continue negotiations towards a Comprehensive Test Ban (CTB) treaty.
1974 Threshold Test Ban Treaty agreed by US and USSR bans tests over 150 kilotonnes.
1976 Peaceful Nuclear Explosion Treaty sets further limits on the size of explosions.
1977-80 The US, UK and USSR resume direct discussions on testing.
1982 The US breaks off the discussions.
1982-83 The Conference on Disarmament (CD) in Geneva sees the establishment of a Verification and Compliance Working Group, but the group is not mandated to restart negotiations.
1984-89 The CD fails to obtain consensus on a mandate for talks.
1985-87 The USSR implements a unilateral moratorium.
1987 The US and USSR announce an agreement to revise the Threshold and Peaceful Nuclear Explosion treaties, and work towards a comprehensive test ban. …