<i>‘It is easy to get lost in the maze of optional clause declarations submitted under Article 36(2) of the ICJ Statute. Nearly all States limit the Court’s jurisdiction by supplementing their declarations with reservations, and these become longer and more complex. Robert Kolb’s newest book is a guide through the maze of the optional clause system. It identifies standard types of reservations, highlights trends in the practice of States and distils key takeaways from the ICJ’s jurisprudence. It does not ignore the complexity of the topic, but provides us with a roadmap to confront it. Students, academics and practitioners will read it with benefit.’</i>

- Christian Tams, University of Glasgow, UK,

<i>‘Robert Kolb is one of the most erudite and prolific scholars of international law. A master in both theoretical and practical-technical questions, he is invariably devoted to methodological rigour. Excellently argued, this book fills the gap on reservations to optional declarations granting jurisdiction to the ICJ in a clear, systematic, and comprehensive way.’</i>

- Carlo Focarelli, Roma Tre University, Italy,

<i>‘Professor Kolb’s trenchant and thorough assessment provides fascinating insights into the conflicted manner by which States expose themselves to the International Court of Justice’s jurisdiction—on the one hand, opting for ICJ scrutiny; on the other hand, formulating reservations that deny such scrutiny, often in areas of the greatest import.’</i>

- Sean D. Murphy, George Washington University, US,