British nuclear testing in the United States would be foregone, and the Americans were under no obligation to make the test site available for subsequent tests. Also, as Lord Cherwell noted, an American test meant that "in the lamentable event of the bomb failing to detonate, we should look very foolish indeed." In the end, Monte Bello was chosen, and the first British atomic bomb was tested there in Operation Hurricane on 3 October 1952. The next British test series, Operation Totem, was conducted at Emu Field in South Australia, but at their conclusion, the British government formally requested a permanent testing site from the Australian government,
History of the Teller–Ulam design "secret"), the United States agreed to exchange some of its nuclear designs with Great Britain, leading to the 1958 US-UK Mutual Defence Agreement. The People's Republic of China detonated its first device using a Teller–Ulam design June 1967 ("Test No. 6"), a mere 32 months after detonating its first fission weapon (the shortest fission-to-fusion development yet known), with a yield of 3.3 Mt. Little is known about the Chinese thermonuclear program, however. Very little is known about the French development of the Teller–Ulam design beyond the fact that they detonated a 2.6 Mt device in the "Canopus" test in August