The human rights revolution of the last half century has begun to redefine the world’s understanding of the relationships among individuals, the state, and violence. This masterful treatise by Teitel, a law professor at New York Law School, offers one of the best explanations yet of the complex, shifting normative foundations of international law. Whereas the old international legal order emphasized “state security,” defined by borders, statehood, and territory, the emerging focus is on “human security”: the protection of persons and peoples. The result is what Teitel calls “humanity’s law,” a new discourse on violence and world politics that brings together and crystallizes a multitude of small but important shifts in international human rights law, the law of war, and international criminal justice. She chronicles the way these ideas have changed as courts, tribunals, advocacy groups, and international organizations have interpreted and extended the Universal Declaration of Human Rights, the Geneva Conventions, and other enshrinements of principles about rights and responsibilities relating to war and justice. This book is an indispensable guide to understanding these intellectual transformations and their complicated implications for policymakers and the international community.