The U.S. Supreme Court case Jose Ernesto Medellin v. Doug Dretke, Director, Texas Department of Criminal Justice, Correctional Institutions Division (2004) revolved around the issue of whether an international court ruling could impact a state's criminal justice proceedings. The petitioner, Jose Ernesto Medellin - a Mexican national convicted for murder in Texas - argued that his conviction should be overturned because he was not informed about his right to contact the Mexican consulate after his arrest as required by the Vienna Convention on Consular Relations treaty. The International Court of Justice had ruled in favor of Mexico and 51 other nationals who were denied their consular rights under this treaty including Medellin but Texas courts refused to review or reconsider these convictions based on this ruling arguing that it did not have legal effect unless Congress implemented legislation enforcing it domestically or if the President made it binding law through executive action. In its decision, however, the Supreme Court held that neither federal nor international law provided a basis for judicial enforcement of ICJ rulings and hence declined to intervene.

In the dissenting opinion for Medellin v. Dretke, Justice O'Connor argued that the majority's decision to deny habeas corpus relief was premature and potentially harmful to U.S. international relations. She emphasized that Jose Ernesto Medellin had not been informed of his right under the Vienna Convention on Consular Relations (VCCR) to contact his consulate after arrest, a violation acknowledged by both Texas courts and the International Court of Justice (ICJ). While she agreed with the majority that ICJ judgments are not directly enforceable in U.S. courts, she contended they should be considered as part of federal law when determining whether a VCCR violation occurred. Furthermore, she expressed concern about potential repercussions if foreign countries retaliated by denying similar rights to American citizens abroad or disregarding ICJ rulings favorable to America due its refusal here.