Trident (UK nuclear programme) Agreement merged with the American Manhattan Project to create a combined American, British, and Canadian project. The British government expected that the United States would continue to share nuclear technology, which it regarded as a joint discovery, but the United States Atomic Energy Act of 1946 (McMahon Act) ended technical co-operation. Fearing a resurgence of United States isolationism, and Britain losing its great power status, the British government resumed its own development effort. The first British atomic bomb was tested in Operation Hurricane on 3 October 1952. The subsequent British development of the hydrogen bomb, and a fortuitous international relations
British hydrogen bomb programme in 1949. The successful test of an atomic bomb represented an extraordinary scientific and technological achievement. Britain became the world's third nuclear power, reaffirming its status as a great power, but hopes that the United States would be sufficiently impressed to restore the Special Relationship were soon dashed. On 1 November 1952, the United States conducted Ivy Mike, the first successful test of a true thermonuclear device (also known as a hydrogen bomb). Due to its physical size and use of cryogenic liquid deuterium, it was not suitable for use as a deliverable weapon, but the Castle Bravo test on