In 2008, The New York Times created an infographic based on the book The Nuclear Express: A Political History of the Bomb and its Proliferation — charting how nuclear weapons have proliferated among nations since the United States became the first "nuclear state" in 1945. Though the chart is somewhat dated, it is still a fascinating look at how transfers of nuclear secrets and technology have unfolded over 65 years.

See the full infographic at The New York Times