1950 
                                 January 27-Fuchs confesses that he gave atomic secrets to the Soviets.
                                 U.S. above-ground tests start in Nevada.
                                 January 31-Truman announces the decision to proceed with the H-bomb. 

                          1952 
                                 October 3-First British atomic detonation, Monte Bello Islands, Australia.
                                 October 31-U.S. explodes first fusion device, Mike, of 10.4 Mt at Eniwetok. 

                          1953 
                                 August 12-First Soviet fusion device exploded on a tower in Siberia. 

                          1954 
                                 January 21-First nuclear-powered submarine, U.S.S. Nautilus, launched.
                                 March 1-The 'BRAVO' H-bomb test; Marshall Islanders and the crew of the "Lucky Dragon"are
                                 affected by fallout.
                                 April 12 to May 6-Oppenheimer hearings deny him access to nuclear secrets. 

                          1955 
                                 November 22- First fusion device test by the Soviet Union, it had a yield of 1.6 megatons. The
                                 development was lead by Andrei Sakharov. 

                          1957 
                                 May 15-First British H-bomb exploded at Christmas Island.
                                 September 19-First underground test, Rainier, 1.7 kilotons. 

                          1958 
                                 November, 1958 to September, 1961-U.S., U.K., and U.S.S.R. observe an informal
                                 moratorium on nuclear tests.