1958 US–UK Mutual Defence Agreement as an atomic spy, caused the proposal to be dropped. The June 1951 defection of Donald Maclean, who had served as a British member of the Combined Policy Committee from January 1947 to August 1948, reinforced the Americans' distrust of British security arrangements. The first British atomic bomb was successfully tested in Operation Hurricane on 3 October 1952, but although it was more advanced than the American bombs of 1946, Britain was still several years behind in nuclear weapons technology. The United States conducted Ivy Mike, the first nuclear test of a true thermonuclear device (also known as a hydrogen
Agathe (atomic test) Agathe (atomic test) Agathe (aka Agate) was the name of the first French nuclear underground test. It was an atomic bomb detonated in the Hoggar mount (near In Ekker) of the then French Sahara desert on November 21, 1961, during the Algerian War (1954–62). Agathe was the first test of the jewel designation series running from 1961 until 1966. Minor and major incidents occurred during these experiments, the most important being the Beryl incident on May 1, 1962, where the nine militarymen of the "621ème Groupe d'Armes Spéciales" unit were heavily contaminated (600 mSv) as portrayed in the 2006 docudrama