See the Videos & Podcasts from the Workshop

Substance of the Workshop

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 workshop brought together experts to discuss current trends in the study of interpretation in international law. Confirmed participants include: Professor Hélène Ruiz Fabri (MPI Luxembourg), Professor Gleider Hernández (KU Leuven and Open Universiteit); Professor Photini Pazartzi (Athens); Professor Kirsten Schmalenbach (Salzburg); Professor Ramses Wessel (Groningen); Professor Pauline Westerman (Groningen); Dr Odile Ammann (Zurich); Dr Irina Buga (De Brauw); Dr Eva Kassoti (Asser Institute); Dr Daniel Peat (Leiden), and Dr Efthymios Papastavridis (Oxford; Athens).

Workshop Schedule

10.00-10.30Opening Remarks: Professor Panos Merkouris (TRICI-Law)
10.30-11.30Keynote Speech: Professor Hélène Ruiz Fabri (MPI Luxembourg)  
12.00-13.30Panel 1: A Normative Approach to Interpretation in International Law: Prospects and Challenges
Chair: Professor Pauline Westerman (Groningen)
Professor Gleider Hernández (KU Leuven and Open Universiteit) Indeterminacy, Authority and International Law as a System
Dr Daniel Peat (Leiden) – Disciplining Rules? The Evaluative Dimension of Articles 31 and 32 of the Vienna Convention
Dr Sotirios Lekkas (TRICI-Law) – The Uses of the Works of the International Law Commission in International Adjudication
14.00-15.30Panel 2: The Rule of Treaty Interpretation and its Evolution
Chair: Professor Ramses Wessel (Groningen)
Professor Kirsten Schmalenbach (Salzburg) – The Impact of Rules and Acts of International Organisations on the Interpretation of Treaties
Dr Irina Buga (De Brauw) – The Treaty Impact of Subsequent Customary International Law: Pushing the Boundaries of the Rules of Interpretation?
Professor Panos Merkouris (TRICI-Law) – The Principle of Systemic Integration
16.00-17.30Panel 3: Interpretation and Sources of International Law beyond Treaties
Chair: Professor Photini Pazartzis (Athens)
Dr Eva Kassoti (Asser Institute) – Interpretation as a Tool for Ascertaining the Creation of Obligations in International Law: A Unified Framework for Interpreting International Juridical Acts
Dr Odile Ammann (Zurich) – The Interpretation of Customary International Law: Art or Science?
Dr Efthymios Papastavridis (Oxford; Athens) – The Interpretation of Security Council Resolutions
17.30-18.00Concluding Remarks

This workshop is part of the project ‘The Rules of Interpretation of Customary International Law’ (‘TRICI-Law’). This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 Research and Innovation Programme (Grant Agreement No 759728).