International lawyers are familiar with the concept of extraterritoriality the application of one country's laws to persons, conduct, or relationships outside of that country. Yet the transborder application of law is not limited to international cases. In many states, the presence of indigenous peoples, often within defined borders, creates an analogous puzzle. This Article begins a comparative study of foreign- and native-affairs law by examining the application of domestic laws to foreign facts ("extraterritoriality") and to indigenous peoples, often called "nations" ("extranationality"). Using a distinctive double-comparative perspective, this Article analyzes extraterritoriality and extranationality across three countries: the United States, Canada, and Australia.

Part I addresses the treatment of extraterritoriality across these three countries. Part II does the same for extranationality. These comparative law analyses pay special attention to the sources of the legal regimes and to the similarities and differences among the three countries' approaches. But comparative law is not only a tool to evaluate extraterritoriality and extranationality separately; it is also a tool to compare approaches toward foreign affairs with approaches toward indigenous peoples—here embodied in a presumption against extraterritoriality and a presumption in favor of extranationality. Part III takes up this task, focusing on sovereignty, separation of powers, and due process in the context of these rules. Finally, Part IV identifies practical lessons drawn from the manifold approaches to these related issues. In sum, this Article launches a new double-comparative enterprise and, in the process, offers policy proposals derived from the study of the American, Canadian, and Australian approaches to extraterritoriality and extranationality.

Included in

Law Commons