Brian D. Lepard (ed.), Reexamining Customary International Law (Cambridge University Press, 2017). 438 p. Hardcover $125.00.
Reexamining Customary International Law starts with a forward by Michael Wood, the International Law Commission’s (ILC) Special Rapporteur for “Identification of customary international law.” Wood discusses the need for a reexamination of customary international law (CIL) and how this book fits with the ILC’s work on identifying CIL. The opening leads nicely into the introduction by the editor describing the sweeping use of CIL across topic areas and beginning discussion of some of the ways scholars are interrogating issues within the often complex world of defining and demonstrating CIL.
The book then turns to Part I Reexamining Historical and Theoretical Perspectives on Customary International Law. J. Patrick Kelly focuses on the historical aspect by problematizing how CIL was a development of the most powerful Western states, ignoring the practices of non-Western and less powerful Western states and seeming to justify colonial expansion by situating European norms as CIL. Kelly then describes how the persistent objector principle is a relatively recent phenomenon appearing in the ninth edition of Oppenheim’s International Law, not in the first eight editions (p. 79). He argues that this principle makes CIL inconsistent by allowing demonstrations of non-consent to have value despite CIL generally being a set of norms applicable to all nations. The next three chapters all make theoretical arguments surrounding some of the complicated aspects of CIL. Fernando R. Tesón explores fake custom, listing myriad ways fake custom can be perpetuated and why this is a concern. Neils Peterson uses examples and charts to demonstrate the impact of consent in CIL and discuss benefits of rethinking how CIL works in practice. Thomas Kleinlein delves into the murky waters of the relationship between CIL and general principles. Each chapter is filled with dense analyses of this complex area of international law.
Parts II-IV reexamine CIL in different contexts, all interrogating the evidence used to demonstrate CIL and proposing ways to effectively show CIL in each topic area. Jean-Marie Henckaerts and Els Debuf discuss the International Committee of the Red Cross Customary International Humanitarian Law study and Customary IHL database, including how these resources have been used in practice and their impact on shaping the discussion of international humanitarian law. This provides an interesting glimpse into the impact of a nongovernmental organization laying out its take on the rules of CIL in a topic area. Noora Arajärvi discusses examples of international criminal tribunals invoking CIL, examining how opinio juris and state practice show up, or fail to do so, in tribunal judgments.
Turning to human rights, Brian D. Lepard examines the important question of whether human rights norms can be considered CIL given that so many states regularly violate human rights norms, thus challenging the state practice component of CIL. Lepard advocates for a new formulation of CIL in the human rights context. Anne Williams Shavers uses Lepard’s new formulation as a jumping off point to argue for a complementary approach in upholding women’s human rights.
Turning to the skies, Sofia Michaelides-Mateou reviews the evolution of international aviation law, giving particular attention to the relationship between air law treaties and CIL in the context of aviation, and some parallels with law of the sea. Frans G. von der Dunk turns to outer space law arguing that CIL plays a lesser role in outer space law than in other areas of international law with treaty law playing a central role in outer space law.
Part V concludes the book with reflections by Brian D. Lepard connecting the essays to one another and explaining how they collectively contribute to reshaping understanding of CIL. The conclusion brings the book’s title into full view by sharing the big picture of how Lepard believes CIL can and should be reexamined in light of the essays and how the editor believes CIL will move into the future.
CIL is a crucially important but often opaque component of international law. This book is a good, but dense, read for someone seeking to elucidate how CIL is used in different areas of law and understand critiques of that use. This book would fit well in any library looking to build their international law collection.