The Legitimating Role of Consent in International Law

Abstract 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, much of international law is left 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. I. INTRODUCTION One of the striking features of international law, at least as it has traditionally been understood,1 is its consensual nature. To a large degree, international law, unlike domestic law, depends on the consent of those (states) that are governed by it. The extent that this is true, even as a descriptive matter, is disputed, but that large and important parts of international law depend on the consent of states is clear. But the role of consent, and the extent to which it is applicable, remains unclear. In this paper I argue that state consent has an important, although limited, role in establishing the legitimacy of some parts of international law. I argue that certain elements of international law can only be legitimate when consented to by those governed by die law. Here I assume the traditional view that the primary subjects of and actors in international law are states, and that, therefore, state consent is necessary for large parts of international law to be legitimate.1 In so doing, I defend the legitimating role of consent both from proponents of a strong international law, such as Allen Buchanan, and from (relative) international law skeptics, such as Eric Posner and Jack Goldsmith, each of whom argues that consent has no significant role to play in legitimizing international law, although for quite different reasons. I shall, in what follows, make use of a Lockean social contract account to show why actual consent is necessary to legitimize large parts of international law. I do not attempt to give an account of all of international law. I shall discuss customary international law only to a small degree (although I think a rather similar account of it could be given), and I will not discuss jus cogens norms, which are norms binding on all states, at all. jus cogens norms are, obviously, of extreme importance, but they are only a small part of international law. They have, I believe, a different normative structure and foundation than much of international law, and are best dealt with separately - a task I leave for others. I will focus in particular on consent to jurisdiction before international dispute resolution bodies such as the International Court of Justice (ICJ). Although most of my discussion focuses on the ICJ, a similar story could be told, I believe, about other international bodies, such as the World Trade Organization (WTO). For the most part, international adjudicative bodies have jurisdiction only in cases where the parties have consented to the court's jurisdiction. This is so, for example, for disputes heard by the WTO's Dispute Resolution Body, and for disputes heard by the ICJ. In the case of the ICJ, this consent may be specific - consent to jurisdiction given to the court to decide a particular matter, or a more general one arising from a treaty agreement, giving the court jurisdiction over all disputes under the treaty. …