This book studies the struggle to enforce international human rights law in federal courts. In 1980, a federal appeals court ruled that a Paraguayan family could sue a Paraguayan official under the Alien Tort Statute - a dormant provision of the 1789 Judiciary Act - for torture committed in Paraguay. Since then, courts have been wrestling with this step toward a universal approach to human rights law. The book examines attempts by human rights groups to use the law to enforce human rights norms. It explains the separation of powers issues arising when victims sue the United States or when the United States intervenes to urge dismissal of a claim. Moreover, it analyzes the controversies arising from attempts to hold foreign nations, foreign officials, and corporations liable under international human rights law. While Davis's analysis is driven by social science methods, its foundation is the dramatic human story from which these cases arise.