Critical international relations theory is a diverse set of schools of thought in international relations (IR) that have criticized the theoretical, meta-theoretical and/or political status quo, both in IR theory and in international politics more broadly — from positivist as well as postpositivist positions. Positivist critiques include Marxist and neo-Marxist approaches and certain ("conventional") strands of social constructivism. Postpositivist critiques include poststructuralist, postcolonial, "critical" constructivist, critical theory (in the strict sense used by the Frankfurt School), neo-Gramscian, most feminist, and some English School approaches, as well as non-Weberian historical sociology, "international political sociology", "critical geopolitics", and the so-called "new materialism" (partly inspired by actor–network theory). All of these latter approaches differ from both realism and liberalism in their epistemological and ontological premises.
Such theories are now widely recognized and taught and researched in many universities, but are less common in the United States. They are taught at both undergraduate and postgraduate levels in many major universities outside the US, where a major concern is that "a myopic discipline of IR might contribute to the continued development of a civil society in the U.S. that thinks, reflects and analyzes complex international events through a very narrow set of theoretical lenses"