Interpretation in International Law:Rules, Content, and Evolution

Interpretation is ubiquitous in legal thought and practice. In international law, the law and method pertaining to the process of interpretation continues to generate rich debates amongst legal scholars and to pose perplexing questions in international legal practice. From a conceptual viewpoint, the approach of the Vienna Convention on the Law of Treaties (‘VCLT’) reflects the premise that interpretation is, or at least can be, a formal process based on legal rules. Yet, whilst the VCLT rules are increasingly accepted and relied upon by international courts and tribunals, this does not mean that the law on treaty interpretation is static. In fact, the law of treaty interpretation is still undergoing a process of refinement and progressive development, as attested by recent initiatives within the United Nations International Law Commission (ILC). This workshop intends to take stock of the ways in which the law on treaty interpretation has evolved since the adoption of the VCLT. More importantly, it aims to map out the challenges that still lie ahead in this specific area of law. In parallel, broader developments with respect to the law relating to the sources of international law call for a more careful evaluation of the role of interpretation of international law beyond treaties. Notably, the ILC’s previous work on unilateral acts of states provided explicit guidance as to issues of interpretation. What is more, the ILC completed recently its work on the ‘Identification of Customary International Law’, whereas its work on ‘General Principles of Law’ is still ongoing. It is still an open question whether there is space for the development of rules of interpretation in that context. Apart from these areas, the need arises very commonly in practice for the interpretation of rules stemming from acts of international organisations. More generally, are there rules or methods of interpretation with respect to international law beyond treaties? How do they compare to the rule(s) of treaty interpretation and to each other? This Special Issue brought together experts to discuss current trends in the study of interpretation in international law