'In its totality, Customary International Law in Times of Fundamental Change: Recognizing Grotian Moments is a stimulating and challenging examination of how pivotal moments in history can precipitously affect the field of customary international law and international relations. At its best, this book has the potential to influence international law scholars who are deeply entrenched in their own views and spark interest in students of the law who have not yet embarked on their intellectual journeys.' George Washington International Law Review

'Professor Scharf examines the concept of the 'Grotian Moment', providing a critical yet thought-provoking analysis of the instances in which customary international law can, and indeed does, develop with surprising rapidity and limited state practice. Professor Scharf 's contribution is widely set to leave its mark, as acknowledged by the authoritative list of names endorsing the book.' Jonathan Worboys, King's Law Journal

'… this is an excellent book. It is clearly and engagingly written (as anyone familiar with Scharf's previous work would expect). The research underpinning it is similarly faultless. Moreover, it is short and to the point: its arguments are both concisely made and precisely targeted. This book is ultimately an extremely important addition to the literature. Its thesis is at the same time indisputable (in and of itself) and yet highly contestable both in terms of its framing and application to specific examples. Customary International Law in Times of Fundamental Change will undoubtedly spark important debate and further research on the process of expedited custom: a process that is controversial and potentially dangerous, but which - as Scharf ably demonstrates - undeniably occurs.' James A. Green, International and Comparative Law Quarterly