Wikipedia:Today's featured article/May 31, 2020

The British hydrogen bomb programme was the ultimately successful British effort to develop thermonuclear weapons. The successful test of an atomic bomb in Operation Hurricane in 1952 made Britain a nuclear power, but hopes that the United States would be sufficiently impressed to restore the Special Relationship were soon disappointed. In 1954, Cabinet agreed to proceed with the development of the hydrogen bomb. The scientists at the Atomic Weapons Establishment did not know how to build one, but produced three designs: Orange Herald, a large boosted fission weapon; Green Bamboo, an interim design; and Green Granite, a true thermonuclear design. The first series of Operation Grapple tests (newsreel featured) were hailed as a success, but Green Granite was a failure. In November 1957, they successfully tested a thermonuclear design. Subsequent tests demonstrated a mastery of the technology. Together with the Sputnik crisis, this resulted in the 1958 US–UK Mutual Defence Agreement, and the Special Relationship was restored.