Hathaway and Shapiro Closing Post

We want to begin our closing post by thanking everyone who has participated in the symposium on our article this week. We also wish to thank our lead editor at the Yale Law Journal, Philip Levitz, who help arrange this symposium (as well as a forthcoming symposium at Yale Law Journal Online) and who has been truly outstanding in every respect.

It has been wonderful to see the different ways in which each of the participants in the symposium has approached our project. Samantha Besson, much of whose work focuses on the intersection of philosophy and international law, honed in on the jurisprudential issues, including the relationship between enforcement of international law and the juridical status of international law as law. Gary Bass, a leading political scientist, calls for process-tracing and empirical tests of our claims to inform longstanding debates in political science about state motives for compliance with international law. Michael Helfand, an expert on religious law, notes that our case study of the canon law is simply the tip of the iceberg—outcasting is used extensively, we are interested to learn, in religious legal systems. James Gathi, who has written extensively about law in the developing world, rightly points out that the theory of outcasting calls on us to identify the community that creates and withdraws benefits and the values that the community pursues in the process. Peter Spiro, a leading critic of sovereigntist legal scholarship, presses us to say more about the relationship between outcasting and state sovereignty. Each of these posts have helped us to think about outcasting from a different perspective. Together, they have begun precisely the conversation we hoped we might provoke with this article. We are grateful to Opinio Juris, and especially to Duncan Hollis, for creating the forum in which this could happen.

We cannot conclude, however, without discussing Miguel Maduro’s post—the last of the responses to our article. Miguel’s post is a wide-ranging and wonderfully thought-provoking reflection on two key themes: first, the importance of enforcement for the legitimacy of international law, and, second, the relationship between international law and sovereignty. As with all of the posts, we cannot begin to do his comments justice, but we will say a few brief words.

Miguel begins by asking whether we could imagine the use of outcasting by domestic authorities to enforce domestic law. He is skeptical that we would find this acceptable because of the asymmetric and unpredictable character of outcasting. In the domestic legal order, what gives law legitimacy, Miguel argues, is its claim of completeness and comprehensiveness. International law, he says, does not have this. We both agree and disagree. Yes, there are some instances in which outcasting is unpredictable—for example, the use of economic sanctions against states accused of human rights violations. But there are instances in which it is quite predictable—for example, the use of trade sanctions for violations of the GATT. It is not outcasting that makes the legal system unpredictable per se; it is the willingness or unwillingness of states to use the available sanctions to enforce the law. That, in turn, depends on a variety of factors—factors that can sometimes be at least partially addressed by better designed outcasting sanctions (in ways we begin to discuss in the article) and sometimes not. Miguel is right, however, that a legal order that relies on states to enforce is then effectively at the mercy of those states—the success or failure of the legal order depends on the willingness of the members to robustly participate in the outcasting regime. This is both a strength and a vulnerability.

Miguel is also absolutely right to point out that the power of outcasting comes from the emerging interdependence between states. We believe that this is precisely because the expansion of international law has generated benefits on which states increasingly rely. Outcasting threatens states with the loss of these benefits, a loss that is less bearable today than it would have been at a time when those benefits were smaller because the interdependence was weaker. We agree that as interdependence grows, outcasting as a tool will only become more powerful—precisely because the benefits states receive from the international legal system have grown and their vulnerability to having them withdrawn is commensurately increased. And Miguel is correct in his closing observation that if we are right that enforcement through outcasting strengthens the case that international law is law—by answering one common objection to its juridical status—then the legitimacy of international law naturally turns on when and how international law uses enforcement through outcasting. If that is correct—and we think it is—this lends greater urgency to the project in the second half of the article, in which we consider how outcasting sanctions may be used to most effectively enforce the international legal rules they are meant to police.