Can international law be a tool for promoting global justice? In this class, we will explore diverse questions such as if the laws of war can restrain wars of aggression, and whether international courts like the International Criminal Court (ICC) or the International Court of Justice (ICJ) can deter genocide, war crimes, and crimes against humanity? What does international law say about reparations for slavery or colonialism? Can environmental law help reduce climate change and provide justice for climate refugees? Can trade law contribute to a fairer and more equitable trade system? Could better international health law mitigate a future crisis like COVID-19? We will use a global justice approach to ask and try to answer these questions and many others. A global justice approach stresses fairness, political and economic equality of both opportunity and outcome, and accountability. The central goal of the course is to familiarize students with legal, analytical and policy tools to enable them to think and act critically when drafting, implementing, or responding to policies related to international law. We will examine substantive areas of international law such as the use of force and the laws of war, human rights, environmental law, trade law, investment law, and international criminal law. The course uses cases, role-playing, and simulations to help students learn how to work with international law to promote global justice.