Niboyet, J.-P. Keywords: Private international law | Universal jurisdiction | Mots clefs: Droit international privé | Juridiction internationale | ABSTRACT The objective of J.-P. Niboyet’s course is to examine the role, that is, the role that international justice can play in conflict of laws. The author addresses two key issues. The first concerns the system for resolving conflicts of laws applied successively to the following subjects: the determination of the competent law, the qualification, and the effectivene…