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 Sandstone at Los Alamos on July 9 to make arrangements for the tests. They readily agreed that they would be scientific in nature, with Los Alamos supplying the technical direction and the armed forces providing supplies and logistical support. The cost of the tests, around $20 million, was divided between the Department of Defense and the Atomic Energy Commission. Lieutenant General John E. Hull was designated as test commander. Rear Admiral William S. Parsons and Major General William E. Kepner reprised their Operation Crossroads roles as deputy commanders. Joint Task Force 7 was formally activated on October 18, 1947. As its