Sufyan Droubi is a Lecturer in International Law at the University of Dundee

Jean d'Aspremont is Professor of International Law at Sciences Po Paris and the University of Manchester

Introduction: Stories about International Organisations, Non-State Actors and the Formation of Customary International Law - Sufyan Droubi and Jean d'Aspremont
1 International Organisations as Autonomous Actors - Nikolaos Voulgaris
2 Capturing the Juridical Will - Catherine Brölmann
3 Opinio Juris: Between Mental States and Institutional Objects - Sufyan Droubi
4 Beyond the Either-Or Paradigm - Lorenzo Gasbarri
5 Between Anthropomorphism and Artificial Unity - Maiko Meguro
6 Custom as the product of successful argumentative campaigns - Fabian Cardenas
7 Unlearning some common tropes - Jean d'Aspremont
8 International Organizations and non-State actors in the International Law Commission's Conclusions on Identification of Customary International law - Michael Wood
9 The International Law Commission Perspective on Non-State Actors and Customary International Law - Veronika Bílková
10 The International Law Commission in the Eyes of the International Law Commission: Mirror or Looking-glass? - Luíza Leão Soares Pereira
11 The Riddle of Custom: General Assembly Resolutions - Rossana Deplano
12 The United Nations Secretariat and Custom - Jean-Baptiste Merlin
13 The Making of Custom through Sanctions of International Organisations - MaruSa T. Veber
14 The International Committee of the Red Cross and Custom - Iris Müller
15 Treaty Bodies and States: Shaping Custom - Kasey McCall-Smith
16 The Contribution to Customary International Law by Territories under International Administration - William Thomas Worster
17 The formation of customary international law by de facto regimes - Antal Berkes
18 Investors in the Formation of Customary International Law - Tomoko Yamashita
19 Adjudicators, Guardians, and Enforcers: Taking the Role of Non-Governmental Organisations in Customary International Law-Making Seriously - Valentina Azarova
Index

This collection of essays provides the most comprehensive study of the theory and practice of the contribution of international organisations and non-state actors to the formation of customary international law. The book offers new practical and theoretical perspectives on one of the most complex questions about the making of international law.