Custom's Future: International Law in a Changing World. Edited by Curtis A. Bradley. Cambridge, New York: Cambridge University Press, 2016. Pp. xii, 379. Index. $125.
Curtis Bradley's new edited book, Custom's Future: International Law in a Changing World, boldly tackles the questions at the forefront of the contemporary debate about customary international law (CIL): what constitutes state practice; how much state practice is enough; how much time is required; what demonstrates a sense of legal obligation; what is the extent to which treaties and soft law documents serve as evidence of customary law; what is the role that nonstate actors play in generating or confirming rules of customary law; and what does the future hold for CIL?
Custom s Future has all the hallmarks of a highly influential collective work. The topic is extremely timely and of great theoretical and practical significance, and the authors are among the leading scholars in the field, with expertise in a variety of specialty areas, who bring creative and original thinking to bear on their contributions. As someone who recently published a book with Cambridge University Press on this topic, (1) this reviewer was surprised at the number of fresh insights and the amount of new historic facts I picked up from the writings of Bradley, a professor of law and public policy studies at Duke University, and his contributing authors.
As the concept of CIL predates the creation of the modern state system, one might be tempted to conclude that there is not much more of import that could be written on this subject. But continuing and new debates about the formation and content of CIL prompted the UN's International Law Commission (ILC) to take up the subject for a multiyear project in 2011. Bradley is to be lauded for including a chapter in his book coauthored by Michael Wood, the ILC's Special Rapporteur on the topic of CIL. At the same time that Bradley's book was going to press, Wood and his colleagues at the ILC were promulgating a set of conclusions with commentaries about CIL. The initial sixteen draft conclusions/commentaries were issued in 2016, along with an announcement that the ILC would publish a revised final text in 2018 based on the reactions of states and experts. (2)
In this chapter, Wood and his coauthor Omri Sender remind us that CIL "has withstood the test of time, as well as significant political and doctrinal challenges, and remains both useful and credible" (p. 369). They write that the ILC's current work on the subject has verified that "the once-fashionable notion that custom is in crisis, in decline, or even 'dead,' was never much more than an academic (or political) conceit; it had no basis in reality, no support among states, and no following among practitioners" (pp. 367-68).
Bradley includes among his chapter contributors some who are highly critical of CIL and argue that CIL has outlived its usefulness, (3) but the majority of the chapters...