It is often argued that the nuclear non-proliferation order divides the world into nuclear-weapon-haves and have-nots based on a nuclear apartheid. Employing a careful and nuanced discussion of this claim, Elli Louka explores here the emergence of new threshold nuclear weapon states (TNWS), transparency standards, and precautionary preemption. The author analyzes how a carbon-constrained future and energy security are bringing about a renaissance for the nuclear energy industry. This shift will bring more TNWS to the international arena, thereby altering the politics of use of the nuclear instrument. In addition to examining the architecture of the nuclear non-proliferation order, she discusses the fairness and effectiveness of international and regional institutions and scenarios for the future of nuclear weapons. A sophisticated study of a complex issue, this book is a must-read for policymakers and all those who wish to understand the intricacies and challenges of developing institutions to address the nuclear weapons threat.