This book is designed to introduce students to public international law. Topics covered include international public organizations, such as the United Nations and World Trade Organization, international courts, international human rights law, international trade law, and international environmental law. The goal of each study is to examine how nation states cooperate to govern international affairs. There are 10 lessons: (1) There Ought to Be a Law! (The Problem of Enforcement); (2) What Is International Law?; (3) A Dispute Over Fish (A Case Study in How International Tribunals Work); (4) United Nations 101; (5) Regional Organizations: The European Union; (6) Genocide in Rwanda; (7) The International Criminal Court; (8) The International Court of Justice; (9) The Role of NGOs in International Law; and (10) Protecting Labor Rights: The Banana Plantation Battle.