Precedent and procedure in international adjudication

When confronted with the question of the role of precedent in international adjudications textbooks and treatises often provide a standard answer, starting with Article 38(1)(d) ICJ Statute as an authoritative illustration of the source of international law. Accordingly, judicial decisions are perceived as no more than ‘subsidiary means for the determination of rules of law’, a conclusion imposed by reference to Article 59 ICJ Statute, which clarifies that ‘[t]he decision of the Court has no binding force except between the parties and in respect of that particular case’. Yet, decisions of international adjudicators are replete with references to prior cases, both their own and those of their counterparts. The phenomenon is not new and even mainstream reference works frequently acknowledge the increasing importance of judicial decisions. In a nutshell, while precedents cannot bind subsequent decision-makers, they indubitably matter. But what is their role, precisely, in the context of international adjudication? This chapter discusses the role of precedent as a matter of procedure, as well as the role of precedent in the development of international procedural law. It offers a theoretical introduction, clarifying why international adjudicators may cite precedents, and provides an account of the legal framework and procedural rules governing the use of precedents. It provides an empirical assessment of the extent to which precedents are used in international adjudication. It also discusses the use of precedent for the development of international procedural law.