The New York Times > Science > Image > A Chain Reaction of Proliferation
http://www.nytimes.com/imagepages/2008/12/09/science/20081209_BOMB_GRAPHIC.html

This time-line gives a summary of the transfers of nuclear technology and secrets. It starts with the United States in 1945 and moves through USSR (1949), UK & Canada (1952), France (1960) and on to present date 'aspirants'. The New York Times > Science > Image

via @ghensel on twitter