International relations theory

International relations theory is the study of international relations (IR) from a theoretical perspective. It seeks to explain causal and constitutive effects in international politics. Ole Holsti describes international relations theories as acting like pairs of coloured sunglasses that allow the wearer to see only salient events relevant to the theory; e.g., an adherent of realism may completely disregard an event that a constructivist might pounce upon as crucial, and vice versa. The three most prominent schools of thought are realism, liberalism and constructivism.[1]

The modern study of international relations, as theory, has sometimes been traced to realist works such as E. H. Carr's The Twenty Years' Crisis (1939) and Hans Morgenthau's Politics Among Nations (1948).[2][3] The most influential IR theory work of the post-World War II era was Kenneth Waltz's Theory of International Politics (1979), which pioneered neorealism. Neoliberalism (or Liberal Institutionalism) became a prominent competitive framework to neorealism, with prominent proponents such as Robert Keohane and Joseph Nye. During the late 1980s and 1990s, constructivism emerged as a prominent third IR theoretical framework, in addition to existing realist and liberal approaches. IR theorists such as Alexander Wendt, John Ruggie, Martha Finnemore and Michael N. Barnett helped pioneer constructivism.

Aside from realism, liberalism and constructivism, there are prominent rational choice approaches to international relations, such as the bargaining model of war framework introduced by James Fearon. There are also "post-positivist/reflectivist" IR theories (which stand in contrast to the aforementioned "positivist/rationalist" theories), such as critical theory. In recent decades, positivist and post-positivist variants of feminism have grown more prominent in IR theory scholarship.

International relations, as a discipline, is believed to have emerged after the First World War with the establishment of a Chair of International Relations, the Woodrow Wilson Chair held by Alfred Eckhard Zimmern[4] at the University of Wales, Aberystwyth.[5]