Justice Stevens found in Supreme Court case of Texas v Medellin that decisions of UNCLOS tribunal would be enforceable within US

The domestic enforceability of UNCLOS tribunal judgments was confirmed by U.S. Supreme Court Justice John Paul Stevens in Medellin v. Texas, a landmark case in 2008.²⁷ In Medellin, Justice Stevens, writing in a concurring opinion, cited Article 39 of Annex VI for the proposition that UNCLOS members—presum- ably including the United States if it accedes to the convention—are obligated to comply with the judgments of the convention’s tribunals. The Medellin case concerned whether the ICJ’s judgment in 2003 against the United States in the Case Concerning Avena and Other Mexican Nationals (the Avena case) is domestically enforceable. Justice Stevens concluded that the relevant treaties in the Avena case—the U.N. Charter and the Vienna Convention on Consular Relations (VCCR)—did not require the Supreme Court to enforce the ICJ’s ruling. Justice Stevens contrasted the permissive language of the U.N. Charter and the VCCR with the explicit language of UNCLOS and concluded that the convention would indeed oblige the Supreme Court to enforce the judgments of UNCLOS tribunals within the United States.²⁸