A federal appeals court has set a high bar for foreign plaintiffs attempting to use U.S. courts to hold foreign defendants accountable for human rights violations in foreign lands, ruling that liability can be imposed only where it is shown that a defendant “purposefully” aided and abetted a violation of international law.

In a major decision Friday, the U.S. Court of Appeals for the Second Circuit in The Presbyterian Church of Sudan v. Talisman Energy, Inc., 07-0016, clarified the standard for aiding-and-abetting and conspiracy liability under the Alien Tort Statute.