International Relations, as one of the subfields of Political Science in particular and Social Sciences in general, studies the interaction of nation-states, non-governmental organizations, and individuals across national borders in the areas, such as politics, economics, and security. It explains why and how nation-states, non-governmental organizations, and individuals across national borders cooperate and conflict. This course is designed to introduce this subfield to beginning students from a theoretical perspective. It will familiarize students with the most influential and popular theoretical approaches to the study of international relations. It will also help students understand some major contemporary issues across national borders.