Operation Grapple with the American Manhattan Project in August 1943. Many of Britain's top scientists participated in the British contribution to the Manhattan Project. After the war, fearing that Britain would lose its great power status, the British government resumed the atomic bomb development effort, now codenamed High Explosive Research. The successful test of an atomic bomb in Operation Hurricane in October 1952 represented an extraordinary scientific and technological achievement, but Britain was still several years behind the United States in nuclear weapons technology. In July 1954, the Cabinet decided to develop the hydrogen bomb. The United Kingdom Atomic Energy Authority Atomic
Test No. 6 so great that the Soviet Union ceased all assistance to China. Thus, the Number 6 test was indeed an independent endeavor, after the induced military and economic sanctions enacted by the superpowers at the time, the United States and the Soviet Union. Nevertheless, a comparison of other fission-to-fusion timespans may be instructive. The time between the U.S.'s first atomic test and its first hydrogen bomb test was 86 months, for the USSR it was 75 months, for the UK 66 months and later for France, 105 months. The goal of China was to produce a thermonuclear device of at least