«This book has risen brilliantly to the challenge of confronting the complex and under-researched questions raised by the secondary rules of international law of state responsibility. Deconstructing the implicit hierarchy between primary norms and the rules that serve to implement them by showing how the latter can, through the way adjudicators implement them, shape the former is a timely project, a quarter of a century after the finalization of the ILC's articles on States' responsibility but also after the proliferation of jurisdictional mechanisms that have become their primary operators. To find out whether these rules are general - or why they are not - is a remarkably original and fruitful angle to reflect on the legitimacy of the jurisdictional decisions that specify them and their impact on the coherence of international law.»

Hélène Ruiz Fabri, Professor of Public International Law, Director of the Max Planck Institute Luxem

«This is a timely volume. How international courts apply and shape international law, and what outcomes they reach, is largely determined by secondary rules of international law. Such rules help understand why courts reach certain conclusions in one case and other conclusions in another case, even though the applicable rules of international law and the facts may be largely similar. This volume brings together rich contributions by practitioners and scholars on such secondary rules, that advance our understanding of the practice of international courts and their contribution to the development of international law.»

André Nollkaemper, Professor of Public International Law, University of Amsterdam