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 demonstrates 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.

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 demonstrates 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.

This book traces the impact that the International Court of Justice (ICJ), the principal judicial organ of the United Nations, has had on various areas of international law. A number of prominent international experts examine whether, and to what extent, international law has been shaped by the Court's jurisprudence. The informal development of international law through the Court's judgments contrasts with the development of international law through more deliberate means, such as treaty-making. Assessing key areas of international law over which the ICJ has exercised its jurisdiction, such...