Domestic Application of International Law ♦ Book Review 63 Va. J. Int’l L. 535 (2023)

Marry the Domestic and the International: Review of Yuji Iwasawa, Domestic Application Of International Law Focusing On Direct Applicability

PAUL B. STEPHAN

The roots of this book run through an article in this Journal almost forty years ago. Professor Iwasawa, as he was then, came to the University of Virginia School of Law as a Fulbright Scholar in pursuit of an S.J.D. One of the fruits of his stay was an article, The Doctrine of Self-Executing Treaties in the United States: A Critical Analysis. 1 He had picked as his topic perhaps the most fraught question in all of U.S. foreign relations law, something later described by the Restatement (Fourth) of the Foreign Relations Law of the United States as one “of the most complicated doctrines governing the domestic application of treaties in the United States.”2 His interest in the subject evolved and grew, eventually becoming a course of the Hague Academy of International Law delivered in 2002 but, due to his many commitments as a professor and an international lawyer, not published until 2015.3 The book under review here represents a major revision and extension of that course, completed after the author became Judge Iwasawa upon his election to the International Court of Justice in 2018.

To put the issue at a high level of generality, Iwasawa explores the circumstances and legal foundations that lead persons who exercise official power in domestic legal systems – judges of course, but really any and all government actors – to give effect to international law. He explores the use of international law, both customary and treaty-based, by persons who derive their legal authority from somewhere other than the international legal system. These people interpret and perhaps modify these rules by their writings and their actions. An older generation of international lawyers questioned whether any of this practice could count as international law, as opposed to acts of borrowing of no special interests to people outside the legal system where the borrowing occurs. Iwasawa demonstrates that the domestic application of international law is a vital part of the contemporary world, giving international law its relevance and significance even as the practice presents challenges.