The Legitimating Role of Consent in International Law

According to many traditional accounts, one important difference between international and domestic law is that international law depends on the consent of the relevant parties (states) in a way that domestic law does not. In recent years this traditional account has been attacked both by philosophers such as Allen Buchanan and by lawyers and legal scholars working on international law. It is now safe to say that the view that consent plays an important foundational role in international law is a contested one, perhaps even a minority position, among lawyers and philosophers. In this paper I defend a limited but important role for actual consent in legitimating international law. While actual consent is not necessary for justifying the enforcement of jus cogens norms, at least when they are narrowly understood, this leaves much of international law unaccounted for. By drawing on a Lockean social contract account, I show how, given the ways that international cooperation is different from cooperation in the domestic sphere, actual consent is both a possible and an appropriate legitimating device for much of international law.