Even after the departure of two of its most prominent advocates - Chief Justice William Rehnquist and Justice Sandra Day O'Connor - the federalism revolution initiated by the Supreme Court almost twenty years ago continues its onward advance. If recent court decisions and congressional legislation are any indication, in fact, it may have reached a new beachhead in the realm of foreign affairs and international law. The emerging federalism in foreign affairs and international law is of a distinct form, however, with distinct implications for the relationship of sub-national, national, and international institutions and interests.

This article - prepared for a symposium on Missouri v. Holland - draws on the prism of "coordination," as well as related analysis of standard-setting, to question two conventional assumptions about the relationship of sub-national, national, and international institutions. First, there is the common notion that a coherent foreign affairs regime requires "one voice" to speak for the nation. Second is the perception of some inherent conflict in the interaction of international norms and sub-national interests - a sense of international law as silencing (or at least disregarding) sub-national voices. Familiar as they are, both these claims are wrong. Coordination can be achieved in foreign affairs even with multiple voices. International law, meanwhile, may increasingly offer opportunities for states and localities to be heard. Once we appreciate as much, we can begin to develop a richer account of the interaction of sub-national, national, and international institutions, as "our federalism" reaches abroad.