UC Davis

Under two longstanding rules, U.S. courts will not enforce the penal and revenue laws of foreign nations, nor the judgments of foreign courts based upon such laws. Both the penal and revenue rules are rules of common law. But are they rules of state common law or federal common law? Some federal courts have held that the revenue rule is federal common law and preempts inconsistent state law. This essay argues, to the contrary, that the penal and revenue rules — like other rules concerning the conflict of laws and the enforcement of foreign judgments — are rules of state law. Building on Justice Harlan’s concurrence in Zschernig v. Miller, I offer a narrower theory of preemption based on clear federal policies expressed in U.S. treaties. Under this theory, States would be precluded from enforcing foreign tax claims, for example, but could recognize foreign convictions as bars to subsequent prosecutions for the same offense, as some state double-jeopardy statutes have done.