The Extraterritorial Authority of U.S. States

Photo by Kyle Glenn on Unsplash

There is one sentence in Fuld v. PLO (2025) that has always bothered me: that “The Constitution confers upon the Federal Government—and it alone—both nationwide and extraterritorial authority.” This statement is demonstrably wrong, so much so that I was easily convinced by colleagues that it did not need direct refutation. And yet that sentence has been repeatedly cited by lower courts, and it is all over the briefing in this Term’s Suncor v. Boulder County as support for there being some broad “extraterritoriality principle” embedded in the U.S. Constitution (hint: there is not).

So maybe it is worth clarifying: U.S. states have always had some extraterritorial authority, both in terms of other U.S. states and internationally. For example:

• U.S. states have broad leeway to apply their law to disputes that arise outside their borders. Under Allstate Insurance Co. v. Hague (1981), a U.S. state may apply its law as long as it has “a significant contact” with the parties and dispute that is sufficient to generate state interests. As long as that low bar is met, state choice-of-law rules that apply state law extraterritorially do not offend the Due Process Clause or the Full Faith and Credit Clause.
• Such extraterritorial application of state law can involve disputes that arise in other states or disputes that arise in other countries. Indeed, state legislatures may explicitly seek to regulate internationally, as indicated by many states’ adoption of their own presumptions against extraterritoriality.
• The dormant Commerce Clause doctrine acknowledges that state laws may permissibly have extraterritorial effects.
• States can also regulate the conduct of their own citizens outside the United States (at least, on the high seas), as long as that regulation does not conflict with federal law.
• State courts adjudicate cases against defendants who have had no prior physical contacts with the adjudicating state. That can be due to the defendant purposefully directing actions towards the state from afar or because of consent provided through forum selection clauses—even via a forum selection clause that the absent defendant did not himself sign.
• Localities enter into compacts with foreign localities to, for instance, promote trade, foster cultural relations, or coordinate on policy issues. How much these compacts can cover without violating the Treaty Clause and whether they require congressional consent pursuant to the Compact Clause are subject to debate, but at least some of this extensive practice is constitutionally permissible.
• States also arguably have a legitimate role to play in foreign relations, at least until the political branches decide to preempt states on a particular issue.

The authority of U.S. states does not stop at their borders because their interests do not stop at their borders. To the extent that states gave up some of their sovereign authority to enter the Union, the scope of that submission is set out in the text of the Constitution, with nondelegated power reserved to the states under the Tenth Amendment. The scope of states’ extraterritorial authority is admittedly more circumscribed than that of the federal government and is indeed often mediated by the federal government. But the suggestion that state authority is sharply curtailed by state borders is both ahistorical and a dangerous diminution of state power.