Kiobel v. Royal Dutch Petroleum Co. may be a Trojan horse. Observers who are sympathetic to the adjudication in U.S. courts of international legal norms—such as those against torture— have criticized the decision for limiting federal jurisdiction over human rights abuses abroad. Yet, despite this price, Kiobel might ultimately strengthen the foundation of international legal norms in U.S. courts. Chief Justice John Roberts's majority opinion, limiting the Alien Tort Statute (ATS) from reaching overseas, rested on the principle that one sovereign state should not usually apply its laws within the borders of another sovereign state, and that idea is a bedrock principle of international law. The majority avoided the connection to international law by dressing up the presumption against extraterritoriality in a foreign-policy rationale, but its argument does not square with the historical record, especially when it comes to piracy.