The Use of Precedent by International Judges and Arbitrators

In national legal systems, precedent constitutes the starting-point of judges' reasoning. Most of the time, judges hew closely to precedent for purposes of legal certainty and for fear that their decisions might be challenged before higher instances. This practice translates into the stare decisis rule in Common Law, and into the concept of jurisprudence constante in Roman-German Law. In international law, the stare decisis rule has been excluded since 1922, but permanent jurisdictions constantly refer to their previous decisions. Nonetheless, the former are still led to reassess their jurisprudence by various methods in order to take into consideration the evolutions of the law and of international society. Regional jurisdictions are more inclined to do so than global ones. As for arbitral tribunals, they have recourse to legal precedents in a very variable manner according to the area: interstate relationships, international trade, investment or sport. Furthermore, the increase in the number of courts and arbitral institutions introduces the question whether precedents from one dispute settlement institution are relevant to others. The question arises when two courts or tribunals apply the same national law or treaty and when they apply general international law. The challenge is to navigate between two risks: that of jurisprudential incoherence and that of government by judges. Legal precedent in international dispute settlement is neither to be worshipped nor ignored.