Szewczyk: International Custom in the Political Branches

Bart M.J. Szewczyk (Columbia Univ. - Law) has posted International Custom in the Political Branches. Here's the abstract:

Customary international law, through its use within and between the political branches (as well as by federal courts), has become integral to interpreting U.S. law, as the historic line separating domestic and international law is increasingly blurred. Nevertheless, international custom is sometimes misperceived as the exclusive province of the President in his role as the sole representative of the United States in foreign affairs; its function in the Congress has been largely ignored and its use in the courts, misunderstood. Whereas judges should exercise caution in utilizing international custom, political actors should have greater flexibility in incorporating customary international law into their decision-making. The resultant potential risk of illegality by the executive or legislative branch — where custom is misused to evade statutory or constitutional provisions — requires increased scholarly attention to this area of law to promote greater transparency and accountability. For instance, in the recent debate on the lawfulness of U.S. participation in NATO’s intervention in Libya, the Obama Administration used in part the international custom of the responsibility to protect civilians to argue that U.S. military activities in Libya did not constitute hostilities under the War Powers Resolution. Where the core purpose of the Resolution was to avert large-scale military operations (like in Vietnam) without Congressional authorization, the Executive Branch reasoned, it should not be interpreted to apply to limited operations to prevent atrocities (like in Libya). Notably, legislators did not challenge this interpretive argument through binding legislation such as appropriations riders, nor even through non-binding concurrent resolutions whose full legal effect could depend on their recognition under customary international law. This Article fills a gap in the existing scholarship, which has overlooked the role of Congress and its interactions with the Executive Branch over the interpretation of domestic law in light of customary international law. Since this intellectual lacuna can become a self-fulfilling prophecy, the Article seeks to help restore the balance between the political branches over international custom.