This course is an introduction to the analysis of the causes and character of international conflict and cooperation. Theories of international relations are presented and then applied to contemporary and historical cases. The course begins with a foundational review of the different levels at which states interact and the primary theoretical paradigms in the field. It then addresses how states achieve cooperation in the face of international anarchy, a question that has attracted the attention of scholars since Thucydides. The course next addresses basic bargaining theory, which uses insights from economics to explore how bargaining breakdowns, commitment problems, and incomplete information can lead to war. Thereafter we examine three popular topics in contemporary international relations research: the roles that psychology, leaders, and domestic politics play in explaining international conflict and cooperation. We also explore the sources and effects of international institutions such as the United Nations and World Trade Organization. We spend a week studying terrorism, a problem of particular significance in the modern world. We also look at trade, foreign aid, international development, and climate change. We conclude with international law and an exploration of the future of international relations.