1 Introduction; Part 1: Subsequent Practice Among the Different Means of Interpretation; 2 Luigi Crema: Subsequent Agreements and Practice within the Vienna Convention; 3 Marcelo G. Kohen: Keeping Subsequent Agreements and Practice in Their Right Limits; 4 James Crawford: Subsequent Agreements and Practice from a Consensualist Perspective; 5 Bruno Simma: Some Problems Arising in Connection with Subsequent Agreements and Practice; Part 2: The Significance of Subsequent Practice in Different Areas of International Law; 6 Laurence Boisson de Chazournes: Subsequent Practice, Practices and 'Family Resemblance': Towards Embedding Subsequent Practice in its Operative Milieu; 7 Sean D. Murphy: The Relevance of Subsequent Agreements and Practice for Treaty Law to Date and in the Future; 8 Anthea Roberts: Subsequent Practice: The Battle over Interpretive Power; 9 Campbell McLachlan: TBC; Part 3: Subsequent Practice Between Interpretation, Informal Modification, and Formal Amendment; 10 Gerhard Hafner: Subsequent Agreements and Practice: Between Interpretation, Informal Modification, and Formal Amendment; 11 Jose E. Alvarez: Subsequent Practice Between Interpretation, Informal Modification, and Formal Amendment: A Comment; 12 Andrea Bianchi: Law, Time and Change: The Self-Regulatory Function of Subsequent Practice; Part 4: Subsequent Practice and the Domestic Level; 13 Stefan Kadelbach: Domestic Constitutional Concerns with Respect to the Use of Subsequent Agreements and Practice at the International Level; 14 Helene Ruiz Fabri: Subsequent Agreements and Practice: Domestic Constitutions, Courts, and Legitimacy; 15 Ingrid Wuerth: Treaty Interpretation, Subsequent Agreements and Practice, and Domestic Constitutions; Part 5: ILC Study Group on Treaties Over Time; Introductory Report of the Study Group on Treaties over Time; Second Report of the ILC Study Group on Treaties over Time

Under the relevant rules of international law, treaties are interpreted in accordance with the ordinary meaning of the language they use, their object and purpose, and the intention of the drafters, but also in light of the subsequent practice of its parties. This subsequent practice can shed light on articles whose meaning is ambiguous and subsequent agreement can even alter the meaning of treaty provisions. At a time when many of the most important international
treaties are more than fifty years old, subsequent practice plays an increasingly important role in their interpretation.
Treaties and Subsequent Practice discusses the role and relevance of this subsequent practice in the process of dynamic treaty interpretation. The book provides a comprehensive treatment of this topic by eminent commentators, combining contributions which focus on practical cases with chapters examining the theoretical underpinnings of treaty interpretation. The concept of subsequent practice is situated in the more general context of treaty law and international law, looking at
different cases and doctrinal questions to assess its policy dimensions. The book addresses the question of whether subsequent practice plays a more or less significant role in different areas of international law, and whether it can be employed as a partial substitute for formal treaty amendments. It also includes
two previously unpublished reports issued by the International Law Commission's Study Group on this topic.

Georg Nolte is Professor of International Law at the Humboldt University in Berlin. He is a member of the UN's International Law Commission and the chair of the Commission's Study Group on Treaties over Time. He has published widely in the field of general international law, and he is one of the co-editors of our Commentary on the UN Charter (3rd edition, 2012).