Although, today, jus cogens is a recognized element of international law and international legal discourse alike, many issues of vital importance to a well-functioning jus cogens regime remain unsettled. The current debate centers on the following six questions: (1) What is the source of jus cogens obligations? (2) What is the role of consent in the creation and modification of jus cogens norms? (3) How do we identify norms belonging to this category? (4) What does the category comprise? Are there such things, for example, as regional jus cogens or jus cogens principles? Are jus cogens rules necessarily rules of conduct? (5) What are the function and effects of the international jus cogens regime? (6) What is the function of jus cogens in i...