Abstract: This Essay explores a few of the many legal dimensions of the federal government’s regulation of harmful conduct of its own officials and its own nationals outside the borders of the United States. First, Part I discusses statutory regulation of the action of federal officials, as an essential aspect of defining their roles abroad. Second, Part II addresses the currently disputed power of Congress, under the Foreign Commerce Clause, to protect foreign citizens against harm—including sexual abuse—inflicted by U.S. nationals in foreign territory. Finally, Part III examines recent developments concerning constitutional restrictions on extraterritorial federal action, including the denial that the Warrant Clause applies to U.S. citizens, and the surprisingly limited effect of the Supreme Court’s 2008 decision in Boumediene v. Bush10 on other constitutional rights of foreign nationals. The common theme that will emerge from these related inquiries is that legal interpretation must remain open to appropriate recognition of extraterritorial harm.