Kenneth Waltz's Theory of International Politics created a "scientific revolution" in international relations, starting two major debates. In the 1980s it defined the controversy between the neorealists, who believed that competition between states was inevitable, and the neoliberals, who believed that states could cooperate with each other. As the debate wound down with the end of the Cold War in the 1990s, a second more fundamental debate began.

In his 1983 book Nations and Nationalism, British-Czech intellectual Ernest Gellner put forward a theory of nationalism, explaining that the concept of nation is not in fact an ancient notion, as we might first imagine. Rather, it is a modern idea born out of the seismic social and cultural shifts that industrialization brought to the Western world.

While previous scholars of international history had focused on "great men" and their achievements, Paul Kennedy focused on the interdependent relationship between military might and economic growth. In his 1987 work, The Rise and Fall of the Great Powers, he shows why countries that balance the economic and the military can become "great powers." Those that fail to do so, however, risk imperial overstretch and failure.

Western thinking about the Middle and Far East has been distorted by stereotype and inaccuracy. This argument lies at the center of Palestinian-American literary theorist Edward Said's groundbreaking book, Orientalism. Originally published in 1978, it cemented Said's reputation as the father of postcolonial studies.

In his 1807 work Phenomenology of Spirit, G. W. F. Hegel introduced the world to his philosophical system. His most influential work - and the culmination of the German Idealist movement begun in the late 18th century as a response to the works of Immanuel Kant - the book remains one of the undisputed classics of Western thought.