International law pervades the U.S. Code. This will come as a surprise to many members of Congress, as well as to those who accept the common trope that Congress is ignorant about or hostile to international law. It also may be news to foreign affairs scholars who study those areas in which Congress necessarily must interact with international law, such as where the Senate provides advice and consent to treaty ratification or Congress enacts implementing legislation to further U.S. treaty commitments. Even those who have examined these high-profile congressional interactions with international law likely are not attuned to the breadth and depth of Congress’s voluntary interactions with international law in a wide variety of situations in which it legislates.
The little-discussed proliferation of international law throughout U.S. statutes – termed here “statutory international law” – is the launching point for the article. Because limited attention is paid to congressional engagement with international law, current legal literature lacks a descriptive and theoretical account of when, why, and how Congress engages with these norms to advance its legislative goals. This article is the first to systematically examine the phenomenon of statutory international law.
Tracking how these norms find their way into statutes reveals the critical but often unseen influence of the Executive on the language of legislation. Further, the presence of statutory international law in the U.S. Code has important implications for the development of customary international law. It accelerates the amount of state practice that the Executive and courts produce and correspondingly empowers the United States to shape customary international law. This, in turn, reduces customary international law’s notorious democracy deficit. In the domestic context, statutory international law introduces new factors to inform ongoing debates about the Charming Betsy canon of statutory interpretation, while highlighting confounding effects on the separation of powers in foreign affairs.
Ashley S. Deeks, Statutory International Law, 57 Virginia Journal of International Law, 263–324 (2018).