The concept of obligations erga omnes - obligations to the international community as a whole - has fascinated international lawyers for decades, yet its precise implications remain unclear. This book assesses how this concept affects the enforcement of international law. It shows that all States are entitled to invoke obligations erga omnes in proceedings before the International Court of Justice, and to take countermeasures in response to serious erga omnes breaches. In addition, it suggests ways of identifying obligations that qualify as erga omnes. In order to sustain these results, the book conducts a thorough examination of international practice and jurisprudence as well as the recent work of the UN International Law Commission in the field of State responsibility. By so doing, it demonstrates that the erga omnes concept is solidly grounded in modern international law, and clarifies one of the central aspects of the international regime of law enforcement.

Because of its unique nature, the sources of international law are not always easy to identify and interpret. This book provides an ideal introduction to these sources for anyone needing to better understand where international law comes from. As well as looking at treaties and custom, the book will look at more modern and controversial sources.

This book examines an important unresolved question of current international law: the legal position of third-party countermeasures.

Actio Popularis before International Courts and Tribunals examines actio popularis in the context of the symbiotic relationship between procedural and substantive normativity in international law. Actio popularis is an important procedural tool devised to address the challenges posed by the relativization of substantive normativity and recognition of norms established to protect collective interests in international law. Farid Ahmadov’s analysis underlines the ineffectiveness of bipolar litigation in enforcement of collective obligations in international law and the importance of introducing new procedural mechanisms to address the challenges posed by the transition from bilateralist to multilateralist normativity. The volume highlights the subtle link between interpretation of standing rules and the ways in which judicial policy concerns inform decisions of international courts and tribunals on admissibility of actio popularis.

Peremptory Norms of General International Law (Jus Cogens): Disquisitions and Dispositions is a collection of contributions on various aspects of jus cogens in international law.

The Nature of International Law provides a comprehensive analytical account of international law within the prototype theory of concepts.

The Shared Responsibility in International Law series examines the underexplored problem of allocation of responsibilities among multiple states and other actors. The International Law Commission, in its work on state responsibility and the responsibility of international organisations, recognised that attribution of acts to one state or organisation does not exclude possible attribution of the same act to another state or organisation, but has provided limited guidance on allocation or reparation. From the new perspective of shared responsibility, this volume reviews the main principles of the law of international responsibility as laid down in the Articles on State Responsibility and the Articles on Responsibility of International Organizations, such as attribution of conduct, breach, circumstances precluding wrongfulness and reparation. It explores the potential and limitations of current international law in dealing with questions of shared responsibility in areas such as military operations and international environmental law.

This systematic analysis of State complicity in international law focuses on the rules of State responsibility. Combining a theoretical perspective on complicity based on the concept of the international rule of law with a thorough analysis of international practice, Helmut Philipp Aust establishes what forms of support for wrongful conduct entail responsibility of complicit States and sheds light on the consequences of complicity in terms of reparation and implementation. Furthermore, he highlights how international law provides for varying degrees of responsibility in cases of complicity, depending on whether peremptory norms have been violated or special subject areas such as the law of collective security are involved. The book shows that the concept of State complicity is firmly grounded in international law, and that the international rule of law may serve as a conceptual paradigm for today's international legal order.

Fundamentals of Public International Law, by Giovanni Distefano, provides an overview of public international law’s main principles and fundamental institutions. By introducing the foundations of the legal reasoning underlying public international law, the extensive volume offers essential tools for any international lawyer, regardless of the specific field of specialization. Dealing expansively with subjects, sources and guarantees of international law, university students, scholars and practitioners alike will benefit from the book’s treatment of what has been called the “Institutes” of public international law.

This book sets out to articulate a comprehensive theory of customary international law that can effectively resolve the conceptual and practical enigmas surrounding it. It takes a multidisciplinary approach and draws insights from international law, legal theory, political science, and game theory. It is anchored in a sophisticated ethical framework and explores the interrelationships between customary international law and ethics.