In this first decision by the United States Supreme Court on the scope and application of the Convention on the Service Abroad of Judicial and Extrajudicial Documents in Civil or Commercial Matters, better known as the Hague Service Convention, petitioner, a West German company, challenged the respondent’s attempt to serve process on petitioner by serving its wholly owned U.S. subsidiary in accordance with the state’s rules rather than pursuant to the procedures of the Convention. The Circuit Court of Cook County, Illinois, found that the relationship between the German parent and the U.S. subsidiary was such that, under state-law rules of agency, the U.S. subsidiary was the parent’s involuntary agent for service of process. Because service could thus be perfected entirely within the United States, the court held that it was not necessary to follow the procedures of the Hague Service Convention. The Illinois Appellate Court affirmed, and the Illinois Supreme Court denied leave to appeal. The U.S. Supreme Court (per O’Connor, J.) affirmed and held: (1) the Hague Service Convention is “mandatory” and preempts inconsistent state-law methods of service in all cases to which it applies; (2) the Convention applies where there is occasion to transmit a document abroad to charge persons with formal notice of a pending action; and (3) whether it is necessary to transmit a document abroad for such purposes is determined by the forum state’s internal law.