What are the causes of war? How might the world be made more peaceful? In this landmark work of international relations theory, first published in 1959, the eminent realist scholar Kenneth N. Waltz offers a foundational analysis of the nature of conflict between states. He explores works by both classic political philosophers, such as St. Augustine, Hobbes, Kant, and Rousseau, and modern psychologists and anthropologists to discover ideas intended to explain war among states and related prescriptions for peace. Waltz influentially distinguishes among three “images” of the origins of war: those that blame individual leaders or human nature, those rooted in states’ internal composition, and those concerning the structure of the international system. With a foreword by Stephen M. Walt on the legacy and continued relevance of Waltz’s work, this anniversary edition brings new life to a perennial international relations classic.

Kenneth N. Waltz (1924–2013) was a preeminent scholar of international relations. He was Ford Professor Emeritus at the University of California, Berkeley, and was senior research scholar at the Institute of War and Peace Studies at Columbia University, where he began his academic career. His books include Theory of International Politics (1979).

Stephen M. Walt is Robert and Renée Belfer Professor of International Affairs at Harvard University’s John F. Kennedy School of Government.