Forgoing the nuclear option: states that could build nuclear weapons but chose not to do so

1. A Brief History of Existential Risk and the People Who Worked to Mitigate It

“…By some estimates, up to 56 states may have, at one time or another, possessed the capability to develop a nuclear weapons programme, yet the vast majority of these either chose not to engage in nuclear weapons activity or voluntarily terminated their programmes, with only ten states ever having developed nuclear weapons of their own-one of which (South Africa) has since disarmed. 25 In this, and other ways, the various initiatives we describe here have helped to make our world safer, though it remains far from safe. One 2013 study estimated the odds of a nuclear war having occurred between 1945 and 2011 as 61%; 26 however, in truth it is likely still too early to say what our chances really were and, indeed, we may never know.…”