Foreign Affairs Federalism

In the U.S. legal system, the federal government has traditionally been the only rightful arena for the conduct of foreign affairs, especially in the case of national security, military action, international trade, and treaty-making. However, the pervasiveness of globalization and the attendant ease of cross-border interactions, with implications for commerce and terrorism, have brought U.S. states, counties, and municipalities increasingly into the federalgovernment's long-standing province of international relations. For example, states now forge trade relationships with foreign governments through energy and investment contracts that very much resemble treaties. If a foreign sovereign violates any of these contracts or statutes, then civil or criminalaction against that sovereign could interfere with the U.S. federal government's diplomatic relations overseas. Consequently, the legal status of states and local governments in the conduct of foreign affairs is unclear and in need of thoughtful analysis and guidance. In Foreign Affairs Federalism, Michael Glennon and Robert Sloane study the constitutional allocation of foreign affairs powers between the federal government and the states. They explain the current law clearly andaccessibly, identifying those areas where the law can be confidently ascertained. Where the law cannot be determined, they suggest the most plausible or compelling perspectives on existing doctrine. They also appraise existing doctrine against the background of the diverse and incompatible goals and challengesfacing the United States in the twenty-first century.

Foreign Affairs Federalism supplies an important description and analysis of the full range of state and local activity implicating foreign relations, a welcome first book-length treatment of the subject. Foreign Affairs Federalism will help lead constitutional actors, not least the courts, to understand the normalization of the subnational role in global affairs. The issue will become only more important in coming years as political polarization moves beyond the water's edge.

Michael J. Glennon is Professor of International Law at the Fletcher School of Law and Diplomacy, Tufts University. Before going into teaching, he was the Legal Counsel to the Senate Foreign Relations Committee. He is the author of National Security and Double Government (Oxford, 2014); co-author of Foreign Relations and National Security Law, and the author of Constitutional Diplomacy, among other books. His op-ed pieceshave appeared in the New York Times, Washington Post, Los Angeles Times, International Herald-Tribune, Financial Times, and Frankfurt Allgemeine Zeitung.Robert D. Sloane is Professor of Law and the R. Gordon Butler Scholar in International Law at Boston University School of Law.