Realism | Definition, Theories, Examples, Problems, & Facts (2024)

realism, set of related theories of international relations that emphasizes the role of the state, national interest, and power in world politics.

Realism has dominated the academic study of international relations since the end of World War II. Realists claim to offer both the most accurate explanation of state behaviour and a set of policy prescriptions (notably the balance of power between states) for ameliorating the inherent destabilizing elements of international affairs. Realism (including neorealism) focuses on abiding patterns of interaction in an international system lacking a centralized political authority. That condition of anarchy means that the logic of international politics often differs from that of domestic politics, which is regulated by a sovereign power. Realists are generally pessimistic about the possibility of radical systemic reform. Realism is a broad tradition of thought that comprises a variety of different strands, the most distinctive of which are classical realism and neorealism.

Classical realism in international relations

Realists frequently claim to draw on an ancient tradition of political thought. Among classic authors often cited by realists are Thucydides, Niccolò Machiavelli, Thomas Hobbes, Jean-Jacques Rousseau, and Max Weber. Realism as a self-conscious movement in the study of international relations emerged during the mid-20th century and was inspired by the British political scientist and historian E.H. Carr. Carr attacked what he perceived as the dangerous and deluded “idealism” of liberal internationalists and, in particular, their belief in the possibility of progress through the construction of international institutions such as the League of Nations. He focused instead on the perennial role of power and self-interest in determining state behaviour. The outbreak of World War II converted many scholars to that pessimistic vision. Thereafter, realism became established in American political science departments, its fortunes boosted by a number of émigré European scholars, most notably the German-born political scientist and historian Hans Morgenthau. It is the realism of Carr, Morgenthau, and their followers that is known as classical.

Morgenthau’sPolitics Among Nations(1948) helped to meet the need for a general theoretical framework for realism. Not only did it become one of the most extensively used textbooks in theUnited Statesand Britain—it continued to be republished in new editions over the next half century—it also was an essential exposition of the realist theory of international relations. Numerous other contributors to realist theory emerged in the decade or so afterWorld War II, including Arnold Wolfers,George F. Kennan, Robert Strausz-Hupé, Henry Kissinger, and the theologianReinhold Niebuhr.

According to realism, states exist within an anarchic international system in which they are ultimately dependent on their own capabilities, or power, to further their national interests. The most important national interest is the survival of the state, including its people,political system, and territorialintegrity. Other major interests for realists include the preservation of a nation’s cultureand economy. Realists contend that, as long as the world is divided into nation-states in an anarchic setting, national interest will remain the essence of international politics.

Classical realism was not a coherent school of thought. It drew from a wide variety of sources and offered competing visions of the self, the state, and the world. Whereas Carr was influenced by Marxism, Morgenthau drew on Friedrich Nietzsche, Weber, Carl Schmitt, and American civic republicanism. Classical realists were united mainly by that which they opposed. Critical of the optimism and explanatory ambition of liberal internationalists, classical realists instead stressed the various barriers to progress and reform that allegedly inhered in human nature, in political institutions, or in the structure of the international system. The fortunes of classical realism, grounded as it was in a combination of history, philosophy, and theology, waned during the era of social-scientific behaviourism in the 1960s. Its fortunes were revived by the emergence of neorealism during the 1970s.