Written as the decade-long Syria conflict nears an end, this is the first book-length treatment of how the Syrian war has changed international law. In The Syrian Conflict’s Impact on International Law, the authors explain the history of the current conflict in Syria and discuss the principles and process of customary international law formation and the phenomenon of accelerated formation of customary international law known as Grotian Moments. They then explore specific examples, including how use of force against ISIS in Syria has changed the law of self-defense against non-state actors, how the allied airstrikes in response to Syria’s use of chemical weapons have changed the law of humanitarian intervention, and others. This book seeks to contribute both to understanding the concept of accelerated formation of customary international law and the specific ways the Syria conflict has led to development of new norms and principles in several areas of international law.