>In the 1960s World War II was well over, and the United States and the Soviet Union were both settling into a nice, long, cold war. Both countries were nervous

>In the 1960s World War II was well over, and the United States and the Soviet Union were both settling into a nice, long, cold war. Both countries were nervous, knowing that each had designed and built nuclear weapons. At least, though, they were the only two countries that could manage it. Nice article but it gets the time-scales slightly wrong. The Soviet Union tested their first device in 1949. The United Kingdom in 1952 (and their first thermonuclear bomb in 1957). France in 1960. China in 1964. So by the time this programme began, all the countries in the NPT nuclear club already had fission bombs and at least the UK had a hydrogen bomb. The idea was not to figure out which country would be third but just how many nuclear powers there would be. 1967 is only one year before the first countries signed the NPT so proliferation was clearly on everyone's mind at that time.