The Tenth Clause of Article I, Section 8 of the Constitution grants to Congress the power "[t]o define and punish ... Offenses against the Law of Nations...."(1) Rarely cited by the Supreme Court, relied upon in only a handful of cases, the Offenses Clause has been the subject of minimal scholarly commentary, with no analysis of its full significance. Yet the long-ignored Clause lies at the heart of the dispute over federalism and foreign affairs and is central to a hotly debated constitutional issue: the federal government's authority, pursuant to the foreign affairs power, to regulate areas traditionally governed by the states.
Properly understood, the Offenses Clause grants Congress exceptional powers to incorporate international law into federal law, even when such norms infringe upon areas otherwise regulated by the states. The failure to understand the broad authority contained in the Offenses Clause, and its role in the battle over federalism and foreign affairs, has hampered full understanding of the federal government's foreign affairs powers. The Offenses Clause provides heretofore unrecognized support for a broad interpretation of that power, support rooted not in the structural implications of the Constitution, but in a specific, enumerated constitutional power.
Although federal dominance over foreign affairs has long been an accepted pillar of our constitutional structure, tensions about the source and extent of that power have been ever present. These disputes have a new significance today, when the nature of international relations has changed dramatically. Contacts among nations are no longer dominated by trade, diplomacy, and war, and are no longer conducted by governments and merchants along well-defined paths. Individuals, local governments, and nations now communicate directly and almost instantaneously across international borders. Increased interactions have led to increased interdependence, and to the recognition that the internal policies of one nation impact directly on its immediate neighbors, its region, and even the world. In a striking response to the international concern about domestic actions, the world community has developed detailed norms prohibiting international human rights violations committed by government officials within their own national borders and against their own citizens. Over the past decade, violations of such rights have led to international criminal prosecutions,(2) as well as to wars such as the recent military action in Kosovo.(3)
This expansion of the terrain governed by international law and of the range of players participating directly in foreign relations poses a challenge to our interpretation of the foreign affairs power. Several scholars have argued in recent articles that federal authority to implement international law obligations is subject to limits imposed by federalism, and that the federal government should not maintain exclusive constitutional power over the implementation of international law, given the evolution of that law to regulate formerly domestic matters. Peter Spiro and Curtis Bradley, for example, both stress the fading distinction between domestic and foreign affairs. Spiro argues that the doctrine of exclusive federal control over foreign affairs "was once appropriate, even imperative, but is fast becoming obsolete" in the face of increasing state and local government activities in the international arena.(4) Bradley criticizes what he calls "foreign affairs exceptionalism," and urges the application of "the usual constitutional restraints" to federal foreign affairs decisions.(5) He concludes that federal foreign affairs powers should be subject to the limitations imposed by the states' primary responsibility for domestic affairs--even where domestic actions implicate foreign policy concerns.(6)
Questions about the viability of an exclusively federal foreign affairs powers are heightened by the Supreme Court's revived emphasis on states' rights. In a rapid series of cases over the past several years, the Court has limited Congress's power to legislate pursuant to both the Commerce Clause and the Fourteenth Amendment,(7) and has redefined structural limits on the federal power to impose mandates on the state governments.(8) These federalism decisions have the potential to alter the definition of state sovereignty within the federalist paradigm. This shift in the constitutional landscape has given rise to additional doubts about the future of the federal foreign affairs power, where federal efforts to enforce international obligations intrude into areas otherwise left to state control.(9)
The Offenses Clause, the only reference to international law in the Constitution, sheds important light on the scope of the foreign affairs powers of Congress and of the federal government in general. An analysis of the Clause supports the conclusion that the framers delegated extraordinary foreign affairs powers to Congress, far broader than those granted on the domestic front. In this sense, the framers understood foreign affairs to be different from other issues facing the nation, justifying exceptional federal powers in order to centralize and regularize our interactions with the rest of the world. In addition, the Offenses Clause provides strong constitutional support for a wide range of congressional actions heretofore based on less specific constitutional powers. Finally, an understanding of the context in which the Clause was adopted and the concerns that it addressed undercuts claims that international law, or even foreign affairs, should be limited to the kinds of international problems confronting the framers in the eighteenth century. To the contrary, the framers understood that the law of nations would evolve in ways that they could not control or predict; to read limits into the federal government's ability to respond to evolving notions of international law would frustrate the purpose of the foreign affairs power in general, as well as the Offenses Clause itself.
To consider an example to which I will return later in this Article, much of the international community considers the execution of defendants who committed their crimes as juveniles to violate international law.(10) The United States has declined to join the near consensus on this issue, refusing to be bound by the customary international law prohibition of capital punishment of juveniles, or to ratify a provision in an international treaty that incorporates this norm. If the President and Congress changed their view as to this rule, indicating that they accepted the customary norm, the international community would view the prohibition as binding upon the United States. Could Congress then enact legislation prohibiting state executions of convicted killers who committed their crimes as juveniles, or would such a statute intrude upon state powers in violation of the Constitution?
Congress's constitutional power to act on this issue could be based on the implied incorporation of international law into federal common law, or on powers implied from the very structure of our government: the federal government controls our relations with foreign States,(11) including the implementation of international law within this country. The Offenses Clause, however, offers a far more direct constitutional source for congressional authority to implement an international law obligation. By its terms, the Clause authorizes Congress to define violations of international law and impose sanctions for those violations. In barring the juvenile death penalty, Congress would be defining capital punishment under such conditions as a violation of international law, and declaring it a federal offense to act in conflict with the international norm.
The dearth of interest in the Offenses Clause, and the failure to recognize its relevance to the federalism and foreign affairs debate or to the particular question posed here, is largely a result of the unexamined assumption that the Clause is limited to the power to define crimes and to impose criminal sanctions. The few commentators to analyze the Clause in depth have assumed, without discussion, that it is limited to penal sanctions.(12) The Supreme Court has never addressed this question, and the handful of cases in which the Court has relied on the Offenses Clause all concern criminal statutes such as laws penalizing piracy or war crimes.(13) Congress itself, however, has twice cited the Offenses Clause in support of the much broader power to regulate civil liability in cases touching upon international law: Congressional reports cite the Clause as support for the authority to determine when foreign sovereigns can be sued in U.S. courts,(14) and for the power to create civil liability for certain international human rights violations.(15)
A close examination of the text of the Offenses Clause, the historical context in which it was drafted, and the constitutional structure of which it is a key part, demonstrates that the Clause was not--and should not be--limited to criminal prosecutions. As used in the Offenses Clause, "offenses" encompasses all violations of international law, regardless of whether criminal or civil sanctions apply, and the power to "define and punish" includes the power to impose civil or criminal regulations and sanctions. Moreover, the constitutional language is not limited to the particular international law norms existing at the time the Constitution was ratified, or to any categories indicated by the types of violations recognized in the eighteenth century, but rather evolves over time as international law continues to develop. Properly understood, the Clause authorizes broad congressional regulation of all activities governed by modern international law. The decision to grant Congress this power to address both criminal and civil violations of that law, as it evolved, reflected a strong...