Although international law lacks centrally organized coercive enforcement mechanisms, it is generally assumed that international law is largely complied with. Why this is so is, however, less straightforward. This course will critically examine the main theories of compliance that have been offered in the literature and closely study the mechanisms of compliance available in international law. The ultimate objective is to problematize and refine the very notion of compliance with international law and reflect on its relevance as an indicator of the impact of international law in international affairs.