Modern international law is widely understood as an autonomous system of binding legal rules. Nevertheless, this claim to autonomy is far from uncontroversial. International lawyers have faced recurrent skepticism as to both the reality and efficacy of the object of their study and practice. For the most part, this skepticism has focused on international law's peculiar institutional structure, with the absence of centralized organs of legislation, adjudication and enforcement, leaving international legal rules seemingly indeterminate in the conduct of international politics. Perception of...