Challenging nuclearism explores how a deliberate ‘normalisation’ of nuclear weapons has been constructed, why it has prevailed in international politics for over seventy years and why it is only now being questioned seriously. The book identifies how certain practices have enabled a small group of states to hold vast arsenals of these weapons of mass destruction and how the close control over nuclear decisions by a select group has meant that the humanitarian consequences of nuclear weapons have been disregarded for decades. The recent UN Treaty on the Prohibition of Nuclear Weapons will not bring about quick disarmament. It has been decried by the nuclear weapon states. But by rejecting nuclearism and providing a clear denunciation of nuclear weapons, it will challenge nuclear states in a way that has until now not been possible. Challenging nuclearism analyses the origins and repercussions of this pivotal moment in nuclear politics.