In this warmly engaging intellectual biography, Viotti traces the life and ideas of Kenneth Waltz, a preeminent figure in post–World War II international relations scholarship. Waltz’s landmark 1979 book, Theory of International Politics , recast realist ideas about world politics in modern theoretical terms, launching decades of research and vibrant debates that continue today. Waltz’s central claim is that the “anarchic” structure of interstate relations shapes the terms of war and peace,