Kenneth N. Waltz is a prominent international relations (IR) scholar. He is one of the founders of neorealism, or structural realism, in IR theory.

His book Man, the State, and War (1954) proposed a three-images view of looking at international relations behavior. The first image was human nature; the second image the nation-state, and the third image the international system.

In Theory of International Politics (1979), he elaborated many of the core principles of modern realist international relations theory. This book also popularized the term bandwagoning.