This talk was given as part of the Oxford Transitional Justice Research (OTJR) Seminar Series. Leila Nadya Sadat is the James Carr Professor of International Criminal Law and Director of the Whitney R. Harris World Law Institute. She serves as Special Adviser on Crimes Against Humanity to the ICC Prosecutor, and in 2008 launched the Crimes Against Humanity Initiative, a ground-breaking project to write the world's first global treaty on crimes against humanity. She is a prolific scholar in the fields of public international law, international criminal law, human rights and foreign affairs, and has published more than 100 books and articles in leading journals, academic presses, and media outlets.