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
Atomic Weapons Establishment have been used in the past to provide assessments for the UK government on nuclear explosions carried out by other countries. The expertise is to be used as part of Britain's contribution to the Comprehensive Nuclear-Test-Ban Treaty which was signed in 1996, but which, as of 2015, has not come into force. Atomic Weapons Establishment The Atomic Weapons Establishment (AWE) is responsible for the design, manufacture and support of warheads for the United Kingdom's nuclear weapons. It is the successor to the Atomic Weapons Research Establishment (AWRE) with its main site on the former RAF Aldermaston and has major facilities