International relations (IR, and also referred to as international studies, international politics, or international affairs) is an academic discipline. In a broader sense, the study of IR, in addition to multilateral relations, concerns all activities among states—such as war, diplomacy, trade, and foreign policy—as well as relations with and among other international actors, such as intergovernmental organizations (IGOs), international nongovernmental organizations (INGOs), international legal bodies, and multinational corporations (MNCs).
International relations is generally classified as a major multidiscipline of political science, along with comparative politics, political methodology, political theory, and public administration. It often draws heavily from other fields, including anthropology, economics, geography, history, law, philosophy, and sociology. There are several schools of thought within IR, of which the most prominent are realism, liberalism, and constructivism.
