Thoughts are turning in many quarters to whether it’s time for a new chapter in the bleak history of nuclear weapons proliferation. What was unthinkable a decade ago is now discussed in mainstream newspapers and research institutesPublic opinion has started to move in the direction of support for Turkey acquiring nuclear weapons – just as it has elsewhere. So far, calls for a domestic nuclear weapons programme have been muted – at least in public. Iran has been on the edge of being nuclear ready and is thought to be more or less nuclear capable. Each near-miss underlines the same truth: nuclear weapons are not just the last line of defence but also the last line of existence.