Treaties and Consent to Be Bound in an Era of Crisis of Multilateralism

Room B.02, 4-12 Little Titchfield Street, London, GB W1W 7BY

The International Law at Westminster (ILaW) Research Centre invites you to a panel that will discuss the role of treaties and consent to be bound in a time when states advocate for increased freedom from international obligations. When sovereignty threatens multilateralism, how does the law of treaties adapt? Indeed, in an era characterised by growing scepticism toward multilateral institutions and increasing reliance on flexible, informal, or provisional arrangements, the traditional foundations of the law of treaties are under renewed scrutiny. This seminar explores the evolving meaning and function of consent to be bound against the backdrop of the contemporary crisis of multilateralism.

The seminar will discuss interrelated themes such as the growing practice of provisional application of treaties as a pragmatic response to multilateral paralysis, the increasingly blurred boundaries between binding and non-binding international instruments, and the relationship between state consent and the expanding institutional role of Conferences and Meetings of the Parties in shaping the normative content of multilateral environmental agreements.

Speakers:

Prof. Malgosia Fitzmaurice (QMUL)

Dr. Agnes V Rydberg (University of Sheffield)

As. Prof. Andrea Spagnolo (University of Turin)

Chair: Dr. Marco Longobardo (University of Westminster)

Speakers Bio

Professor Malgosia Fitzmaurice holds a chair of public international law at the Department of Law, Queen Mary University of London. She is a full Member of the Institue de Droit International. In 2021 she was awarded the Doctorate Honoris Causa of the University of Neuchâtel. She specialises in international environmental law; the law of treaties; and indigenous peoples. She publishes widely on these subjects. She was invited to deliver a General Course in the Hague Academy of International Law in 2028. She is an Editor in Chief of the International Community Law Review and the book series Queen Mary International Law Studies.

Dr Agnes Rydberg is Lecturer in International Law at the University of Sheffield. Her research interests are in the fields of the law of treaties, international environmental law, maritime dispute settlement, climate change law and climate change litigation. She has published extensively on these areas. Agnes is the Deputy Director of the Sheffield Centre for International and European Law. She holds a PhD in Public International Law from Queen Mary University of London, where she also completed an LLM. She also has a BSc in International Law from Orebro University in Sweden. Dr Rydberg is a General Editor of the Elgar Series on Principles of International Environmental Law.

Dr Andrea Spagnolo is Associate Professor of International Law in the Law Department of the University of Turin. He is currently member of the faculty of the Center for Transnational Legal Studies of the Georgetown University, based at the King’s College of London. He received a PhD in International Law from the University of Milan in 2012, and he qualified as Full Professor of International Law in 2025. He is the author of two books and of more than fifty publications on several issues of public international law, including the law of treaties and the responsibility of international organizations.

Dr Marco Longobardo is Reader in International Law at the University of Westminster. He is the author of The Use of Armed Force in Occupied Territory (CUP 2018), for which he was awarded the 2021 Paul Reuter Prize, the co-editor of Justice for Atrocities: Dialogues and Encounters between Latin America and Europe (Routledge 2026), and the author of Sufficient Gravity before the International Criminal Court (Edward Elgar 2026, forthcoming). He sits in the editorial boards of the Journal of International Humanitarian Legal Studies, the International Community Law Review, and the Journal du Droit Transnational.