Medellín v. Texas is the first case in which the Supreme Court has denied a treaty-based claim solely on the ground that the treaty relied upon was non-self-executing. In Foster v. Neilson, the only other case in which the Court had denied relief on this ground, the Court offered its view that the treaty was non-self-executing as an alternative ground for denying relief. The Court soon thereafter disavowed its conclusion that the treaty involved in Foster was non-selfexecuting, and, in the intervening years, it repeatedly declined invitations to deny relief on this or related grounds. Many observers (including me) thought that the Court would again skirt a ruling on non-self-execution in Medellín because the president had issued a memorandum ordering compliance with the judgment of the International Court of Justice (ICJ) in Avena. After all, the Court in American Insurance Ass’n v. Garamendi had recently struck down a California law on the ground that it conflicted with a “policy” reflected in certain sole executive agreements. The president in Medellín seemed to be standing on stronger ground, as he was insisting that state law give way to an obligation imposed by a treaty that had received the consent of the Senate and was accordingly the supreme law of the land. But the Court defied this expectation, with potentially regrettable results for the law of treaties.