In international relations, constructivism is a social theory that asserts that significant aspects of international relations are shaped by ideational factors. The most important ideational factors are those that are collectively held; these collectively held beliefs construct the interests and identities of actors. In contrast to some other prominent IR approaches and theories (such as realism and rational choice), constructivists see identities and interests of actors as socially constructed and changeable; identities are not static and cannot be exogenously assumed. Similarly to rational choice, constructivism does not make broad and specific predictions about international relations; it is an approach to studying international politics, not a substantive theory of international politics. Constructivist analyses can only provide substantive explanations or predictions once the relevant actors and their interests have been identified, as well as the content of social structures. The main competitors theories to constructivism are variants of realism, liberalism, and rational choice that emphasize materialism (the notion that the physical world determines political behavior on its own), and individualism (the notion that individual units can be studied apart from the broader systems that they are embedded in). Whereas other prominent approaches conceptualize power in material terms (e.g. military and economic capabilities), constructivist analyses also see power as the ability to structure and constitute the nature of social relations between actors. Development Nicholas Onuf has been credited with coining the term constructivism to describe theories that stress the socially constructed character of international relations. Since the late 1980s and early 1990s, constructivism has become one of the major schools of thought within international relations. The earliest constructivist works focused on establishing that norms mattered in international politics. Peter J. Katzenstein's edited volume The Culture of National Security compiled works by numerous prominent and emerging constructivists, showing that constructivist insights were important in the field of security studies, an area of International Relations in which realists had been dominant. After establishing that norms mattered in international politics, later veins of constructivism focused on explaining the circumstances under which some norms mattered and others did not. Swathes of constructivist research have focused on norm entrepreneurs: international organizations and law: epistemic communities; speech, argument, and persuasion; and structural configuration as mechanisms and processes for social construction. Alexander Wendt is the most prominent advocate of social constructivism in the field of international relations. Wendt's 1992 article "Anarchy is What States Make of It: the Social Construction