[Harlan Cohen is an Associate Professor of Law at the University of Georgia School of Law]
The Precedent Puzzle
Every year, the Jessup team at the University of Georgia comes to me for a crash course in international law, and every year, I carefully explain to them that they can’t simply argue from precedents (as they would in their other moot court competitions), even precedents from the International Court of Justice, because precedent is not a source of law in international law as it is in domestic law. Nonetheless, I tell them—they, and their opponents, and the judges, will argue from precedent, from the ICJ and beyond, just as everyone in international law does. The trick, I tell them, is to be able explain why the supposedly irrelevant really is relevant.
This is emblematic. On the one hand, we are taught that as a matter of doctrine, judicial decisions construing international law are not in and of themselves law; they are not generally binding on future parties in future cases, even before the same tribunal. On the other hand, we also know that precedent is ubiquitous—from international arbitration, to international criminal law, to international human rights, precedents are argued and applied.
It’s not just that courts and tribunals cite their own precedent. On the contrary, courts and tribunals regularly cite the decisions of other unrelated ones: The precedents from one regional body are argued to others; precedents from human rights courts are argued to investment tribunals; precedents from ad hoc criminal tribunals are applied to domestic civil judgments. Nor is this phenomenon limited to arguments from, to, or in the shadow of international tribunals. The invocation of tribunal decisions as precedent has become part of the fabric of international legal discourse, structuring everyday arguments over the meaning of international law rules even far outside the shadow of any court. Russian and Crimean political leaders invoke the ICJ’s Advisory Opinion on Kosovo’s declaration of independence as precedent for the legality of Crimea’s secession and absorption into Russia. Advocacy groups like Human Rights Watch invoke ICTY decisions in open letters to governments on the legality of tactics used to fight terrorist groups. Academics invoke ICJ decisions in debates over the legality of the use of force against non-state actors. And perhaps most surprisingly, the Department of Justice responds to decisions of the ICTY, European Court of Human Rights, and the U.N. Committee Against Torture in internal, confidential government memoranda. Together with other interpretations of international law by expert committees, by international organizations, or by states, these decisions vie for status as authoritative statements of what international law requires.
But if this puzzling phenomenon is ubiquitous and even widely recognized, it has nonetheless, remained largely unexplained. Why, in the absence of any doctrinal requirement (in some cases, even permission), do some interpretations of international law by some courts, tribunals, or other bodies take on the force of precedent? Why do some interpretations come to be seen as authoritative, allowing some actors to wield them and forcing others to respond?