The Justice Cascadeprovides an overview and an evaluation of one of the most important changes in global politics: the rise of individual criminal accountability for human rights violations. In it, I track the birth and spread of the revolutionary idea and practice that domestic and international courts can hold individual governmental figures, even heads of state, personally accountable for human rights violations. I argue that these powerful practices have the potential to deter future human right violations and help transform domestic and international relations in the 21^st century.The term "justice cascade" describes the increasing speed and power with which the legal ideas and practices of human rights prosecutions spread around the world. In this book, I explain why this new trend has emerged and evaluate its impact.I have organized my analysis into three parts around three big questions. The first part of the book uses a historical approach to answer the question of emergence: what are the origins or sources of new ideas and practices concerning individual criminal accountability for human rights? In Chapters 2 and 3, I trace these origins by looking at the first three cases of domestic trials in Greece, Portugal, and Argentina. In the second part of the book, I try to answer how and why these ideas spread or diffused across regions and, ultimately, across the globe. In Chapter 4, I examine the diffusion of prosecutions, first in domestic courts, and later in foreign courts and international tribunals. The third part of the book tackles questions about effects: what is the impact of these trials? Can human rights prosecutions actually help prevent future human rights violations? Chapters 5 and 6 present work I have done demonstrating that these trials are not dangerous, as some worry, and that they can actually improve protection for human rights. But a skeptic will ask, “If this is really a global trend, what difference does it make for powerful countries like the United States or China?” To begin to answer this question, Chapter 7 focuses on US practices during the “war on terror.”The book is designed to be read straight through, from front to back. However, readers who are mainly interested in the effectiveness of human rights prosecutions could read chapter one, and then move directly to the third part, which addresses effectiveness, especially chapters five and six. The final chapter will speak especially to those interested in international relations theory.