The author argues that the Helms-Burton Act violates general principles of international law. The analysis begins with a brief discussion of the extraterritorial purposes, structure, and operation of the act, followed by a survey of international responses to Helms-Burton by the principal trading partners of the United States: diplomatic protest, formalized dispute settlement under international trade agreements, retaliatory blocking leghlation, and multi-hteral scrutiny in and by international institutions. The author then turns to principles of jurisdiction with a view to demonstrating that Helms-Burton does not meet the applicable thresholds to support either the private right to sue for trafficking in confiscated property under Title III of the act or the governmental exclusion of designated aliens from admission to the United States under Title IV. In this regard, substantive international law arguments in relation to extraterritoriality and nationality, remoteness, the effects doctrine, human rights, and the reasonable expectations of other nations are also considered.