Part IThe Theory of Customary International Law: Fault Lines and the Need for New Approaches

1. 1Between Pragmatism and Disenchantment: The Theory of Customary International Law after the ILC Project

   Jörg Kammerhofer

2. 2The Custom-Making Moment in Customary International Law

   Jean d’Aspremont

3. 3Misinterpreting Customary International Law: Corrupt Pedigree or Self-Fulfilling Prophecy?

   Noora Arajärvi

4. 4The Logic of Absence in Customary International Law: An Open-System Approach

   Anna Irene Baka

5. 5Schrödinger’s Custom: Implications of Identification on the Interpretation of Customary International Law

   Markus P Beham

Part IICustomary International Law as a Source of International Law: Doctrine and History

1. 6The Significance of State Consent for the Legitimate Authority of Customary International Law

   Andreas Follesdal

2. 7Custom and the Regulation of ‘the Sources of International Law’

   Diego Mejía-Lemos

3. 8The ILC’s New Way of Codifying International Law, the Motives Behind It, and the Interpretive Approach Best Suited to It

   Luigi Crema

4. 9Beyond Formalism: Reviving the Legacy of Sir Henry Maine for Customary International Law

   Andreas Hadjigeorgiou

5. 10Enkapsis and the Development of Customary International Law: An Encyclopedic Approach to Inter-legality

   Romel Regalado Bagares

Part IIIThe Practice of Customary International Law Across Various Fora: Diversity of Approaches and Actors

1. 11Customary International Law in the Reasoning of International Courts and Tribunals

   Vladyslav Lanovoy

2. 12Eureka! On Courts’ Discretion in ‘Ascertaining’ Rules of Customary International Law

   Letizia Lo Giacco

3. 13Identification of and Resort to Customary International Law by the WTO Appellate Body

   Mariana Clara De Andrade

4. 14The Practice of Non-state Armed Groups and the Formation of Customary International Humanitarian Law: Towards Direct Relevance?

   Zhuo Liang

5. 15Identifying Custom in Universal Periodic Review Recommendations

   Frederick Cowell

Part IVInterpretation of Customary International Law: Delineating the Stages in Its Life Cycle

1. 16Interpreting Customary International Law: You’ll Never Walk Alone

   Panos Merkouris

2. 17Practical Reasoning and Interpretation of Customary International Law

   Kostiantyn Gorobets

3. 18Different Strings of the Same Harp: Interpretation of Rules of Customary International Law, Their Identification and Treaty Interpretation

   Marina Fortuna

4. 19Customary International Law: Identification versus Interpretation

   Riccardo Di Marco

5. 20‘And in the Darkness Bind Them’: Hand-Waving, Bootstrapping, and the Interpretation of Customary International Law after Chagos

   John R. Morss and Emily Forbes

Part VCustomary International Law in the Practice of Domestic Courts: What Lessons for International Law?

1. 21The Role of Domestic Courts in the Interpretation of Customary International Law: How Can We Learn from Domestic Interpretive Practices?

   Nina Mileva

2. 22Customary International Law Interpretation: The Role of Domestic Courts

   Cedric Ryngaert

3. 23The Relevance of Customary International Law in the Domestic Legal Order of a Federal State

   Gerhard Hoogers