British hydrogen bomb programme Atomic Energy Act of 1946 (also known as the McMahon Act) ended technical cooperation. Fearing a resurgence of American isolationism, and the loss of Britain's great power status, the British government resumed its own development effort, which was codenamed "High Explosive Research". The successful nuclear test of a British atomic bomb in Operation Hurricane in October 1952 represented an extraordinary scientific and technological achievement. Britain became the world's third nuclear power, reaffirming the country's status as a great power, but hopes that the United States would be sufficiently impressed to restore the nuclear Special Relationship were soon dashed. In November
Operation Tumbler–Snapper weapons developments. The military exercise "Desert Rock IV", involving 7350 soldiers, took place during the test series. They trained during the "Charlie", "Dog", and "George" shots and observed shot "Fox". Operation Tumbler–Snapper Operation Tumbler–Snapper was a series of atomic tests conducted by the United States in early 1952 at the Nevada Test Site. The "Tumbler-Snapper" series of tests followed "Operation Buster-Jangle", and preceded "Operation Ivy". The "Tumbler" phase, sponsored by the Atomic Energy Commission consisted of three airdrops which were intended to help explain discrepancies in the actual and estimated blast shock wave damage noted on previous detonations, and to