Extraterritoriality refers to the application of a nation’s law to persons, conduct, or property outside its own territory. Customary international law allows nations to regulate extraterritorially on a number of different bases, including effects, nationality, and universal jurisdiction. Nations generally limit the extraterritorial application of their laws to a greater extent than customary international law requires. For example, the United States applies a presumption against extraterritoriality to federal law and sometimes imposes additional limitations as a matter of prescriptive comity. Some U.S. states have their own presumptions against extraterritoriality, which may differ from the federal presumption.
A Primer on Extraterritoriality
[Updated September 1, 2025] Extraterritoriality refers to the application of a state’s law beyond the state’s borders. Although the word “extraterritorial” often has negative connotations, international law permits a great deal of extraterritorial regulation. In a world where trade, information, crime, and lots of other things regularly cross borders, states often have an interest in…
Continue ReadingOral Argument Recap: Suncor v. Boulder
On Monday, the Supreme Court opened its new Term with oral arguments in Suncor v. County Commissioners of Boulder County (for background on the case, check out our preview post). Justice Alito did not participate as he has recused himself. Here are some takeaways as we await the Court’s decision. No One Is Buying the…
Continue ReadingOT26 Opens with Climate Case
When the Supreme Court opens its new Term next Monday, it will hear oral arguments in Suncor Energy Inc. v. County Commissioners of Boulder County, a case in which the city and county of Boulder are attempting to hold oil and gas companies responsible under state tort law for local harms caused by climate change….
Continue ReadingSecond Circuit: Revenue Rule Does Not Block Fraud Claims by Danish Tax Authority
Two weeks ago, in Skatteforvaltningen v. Markowitz, the Second Circuit Court of Appeals issued a decision involving one of the less frequently invoked doctrines of transnational litigation: the so-called “revenue rule.” This rule essentially bars courts in one country from enforcing the tax laws of another. As the recent decision indicates, though, it does not…
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