Book excerpt: Our Uncertain Nuclear Future : Navigating a Third Nuclear Age of Multipolar Competition -- Cold War Theory Redux : Recalling a Hardnosed Conception of Adversarial Arms Control -- From Theories to Treaties : Learning from the Cold War Negotiating Experience -- A New Arms Race : Transitioning from Post-Cold War Denuclearization to Great Power Nuclear Rivalry -- Arms Control for the Third Nuclear Age : Adapting Old Ideas for New Times.