Register for the April 28th EU/CIL Workshop Now!

The European Union and the Interpretation of Customary International Law (Online & In-Person)

April 28th 2023 / 11:00am – 6:00pm
Senate Room, Academy Building / University of Groningen

Online Attendance Link

In-Person Attendance Registration Link

Workshop Overview

The European Union (EU) not a state, but an international organisation. Yet, as all textbooks explain, the EU is a very special type of international organization to which its Member States have transferred a number of their competences. These competences, together with its status as an international legal person, have over the years allowed the EU to become a global actor in its own right. In its relations with third states and other international organisations, the EU has given itself the brief to not only ‘strictly observe’, but also to ‘develop’ international law (Art. 3(5) TEU).

This development of international law is a multi-faceted process. It takes place not only on the basis of written law, through the many international agreements to which the EU is a party, but also through the EU’s own practice, be it through contributions to law-making at international conferences and meetings, or more importantly through practice that contributes to the formation, interpretation and application of customary international law (CIL). In light of the TRICI-Law project, and EUDIPLO, the present workshop aims to focus on one particular aspect: the interpretation of customary international law within and by the EU.

The workshop examines this issue by taking a dual perspective:

1. An outside-in perspective in which we analyse how CIL has been and is being interpreted in the EU legal order and which choices are made by the legislator and the judiciary. The outside-in perspective primarily aims to assess the interpretation of CIL in the case law of the Court of Justice of the European Union (CJEU). The main questions to be addressed in this context, are, for instance: what methods of interpretation of customary international law have been employed by the CJEU and the other organs of the EU?; to what extent the Court’s interpretation (and perhaps also EU’s related subsequent practice) is in line with or deviates from common/generally accepted interpretations of customary law in international law? It is no secret that the Court (sometimes in an effort to preserve the identity or autonomy of the Union’s legal order) may provide specific interpretations of unwritten international rules that are not necessarily in line, or may move forward at a different pace compared to the rest of the international legal system.
2. An inside-out perspective in which specific interpretations of customary international law by the EU may find their way into the global debates and lead to further clarification, development and/or even possible modification of the existing rules. The inside-out perspective focuses on the ways in which the EU aims to influence the interpretation of customary international law (or in its own terms, further ‘develops’ international law). This not only happens through specific interpretations of international rules, but also through practices of the Union in the areas of for instance treaty law and diplomatic and consular law. This inside-out perspective may also lead to an inquiry into the blurry lines between interpretation and modification of a rule of customary international law.

Workshop Schedule *Amsterdam Time Zone (CET) (UTC+01:00)

11:00         Walk-in / registration

11:15         Introduction to the workshop by Panos Merkouris (University of Groningen; PI TRICI-Law project)

11:30         Panel 1 / The EU’s Approach to Customary Law and its Interpretation

Chair: Marina Fortuna (TRICI-Law)

Fernando Lusa Bordin (Sidney Sussex College, University of Cambridge), The EU and Customary International Law: Insights from a Kindred Project

Jed Odermatt (City University London), EU Law as an Interpretive Lens: Customary International Law before the EU Courts

Eva Kassoti (T.M.C. Asser Institute, The Hague), Interpreting Customary International Law: The View from the CJEU

13:00         Lunch (including visit to the Groningen Forum) 

14:30         Panel 2 / EU’s Interpretation of Customary Rules on the Law of the Sea & the Environment

Chair: Nina Mileva (TRICI-Law)

Markus W Gehring (Faculty of Law, Cambridge and Yale Law School), From Environmental to Sustainability Impact Assessment – A new Interpretation of an Established Customary Norm Developed by the European Union

Efthymios Papastavridis (Faculty of Law, Oxford University), The EU and the Interpretation of CIL of the Sea: Affirming or Modifying the relevant Rules?

Mihail Vatsov (European Commission), The Duty to Cooperate in the Management of Shared Fish Stocks under Customary International Law: Revisiting the Mackerel War                

16:30         Panel 3 / A Comparative Perspective on the Interpretation of Customary Law by the EU

Chair: Ramses Wessel (EUDIPLO)

Alessandra Gianelli (Sapienza University of Rome Law School), Comparing the interpretation of CIL: The CJEU and Other International Dispute Settlement Bodies

Mark Konstantinidis (King’s College London), From Vienna to Luxembourg: Straight Path or Obstacle Course?

Teresa Cabrita (KU Leuven), EU Actors’ Interpretations of Customary International Law: on the Interpretation and Operation of Treaties beyond Casuistic Judicial Settings

18:00  Closure of the workshop by Ramses A. Wessel (University of Groningen; Coordinator EUDIPLO)