This Article presents the first systematic study of foreign sovereign amicus briefs in the Supreme Court. Based on an analysis of the briefing, oral arguments, and opinions in every Supreme Court merits case involving a foreign sovereign amicus since 1978, this Article argues that foreign sovereigns do and should play an important role in shaping foreign relations law.
The Article begins with an empirical investigation of which sovereigns file, the types of cases in which they file, and the nature of the arguments they make. To a surprising extent, the Court cites foreign sovereign briefs, discusses them at argument, and even grants oral argument time to foreign sovereign amici—all despite the widespread perception that the Court is ambivalent or even hostile to foreign and international law.
The Article then situates the Supreme Court’s treatment of foreign sovereign amici within a larger story about how the Court approaches foreign relations questions. Although scholars have attempted to systematize and explain the deference the Court gives to the U.S. government in foreign relations cases, they have largely ignored the role that foreign sovereign amici play in the very same disputes. Accounting for the role of foreign sovereign amici challenges existing scholarly accounts of how and why the Court defers to the U.S. government on foreign relations issues.
The Article argues that the reasons underlying the Court’s deference to the U.S. government—the executive’s expertise, status as a lawmaker, and exercise of control over relevant policies—often apply to foreign sovereigns as well. This overlap in justifications for deference supports treating foreign sovereign amici similarly to the U.S. government in cases involving “international facts,” treaty interpretation, and customary international law. In cases involving foreign law, the justifications for deference suggest that foreign sovereign amici should receive more deference than the U.S. government.
In sum, attention to foreign sovereign amici sheds light on executive-to-judicial transnational networks and provides a more nuanced picture of the competing influences on the Court’s foreign relations jurisprudence.