International criminal law is now an established subset of public international law whose content is being actively litigated in domestic and international fora. Although many of the issues that had long been the subject of scholarly speculation are now part of a burgeoning jurisprudence, important areas of law remain unsettled. Accordingly, this casebook cannot promise a complete treatment of this now established field. Instead, we have endeavored to revel a bit in the open questions in our Notes, Questions, and Problems. International criminal law remains a dynamic area of law, which is what makes this course such a joy and such a challenge to teach.