In a few days, students in the United States will return to university, and thousands of them will enroll in international relations (IR) courses. They will be instructed on the major theories of IR, like realism, liberalism, and constructivism. Unfortunately, for them and for the discipline, one of those theories is increasingly unhelpful for understanding how global affairs really work.
Perhaps ironically, realism has become unrealistic.
Prominent realists have emerged as outspoken critics of U.S. foreign policy, arguing that Washington should pursue a less ambitious, more restrained approach to the world. Yet this theoretical approach has become unsustainable. If, for decade after decade, the world’s most powerful country is not behaving the way that realist theory predicts, then at a certain point, it is the theory—rather than Washington—that needs to change.
International relations is a type of social science. Social sciences, like economics, political science, psychology, sociology, and anthropology, attempt to explain how the social world works. Specifically, IR seeks to explain conflict and cooperation among nation-states. This is, in social science jargon, the dependent variable—the outcome to be explained. Why do states cooperate? They engage in international trade and investment, form alliances, and transfer arms. And why do states sometimes come into conflict? They issue demarches, sanction each other’s economies, and, at the extreme, fight wars.






