Nadine Perrin (plaintiff) filed a petition seeking (1) a divorce from her husband, Jean Jacques Perrin (defendant), in the State of Chihuahua in Mexico and (2) custody of the Perrins’ minor son. The Perrins were citizens of Switzerland, and Nadine had personally signed the municipal registry of residents of the City of Juarez in Chihuahua, thereby submitting herself to the jurisdiction of Chihuahua courts. At a hearing, Nadine personally appeared before a Chihuahua court while Jean’s attorney appeared and filed a consenting answer to Nadine’s petition. The Chihuahua court granted the divorce, entered a judgment, and gave custody of the son to Jean. Later that year, Jean and his son traveled to St. Thomas in the U.S. Virgin Islands to engage in a charter business for the tourist season. While they were there, Nadine filed another complaint for divorce against Jean in the U.S. District Court for the Virgin Islands, seeking custody of the son. Jean filed a motion to dismiss the petition for lack of subject matter jurisdiction, arguing that the Perrins were not married in light of the divorce decree entered by the Chihuahua court. The district court denied the motion. Jean appealed.