Navani argued that the new custody order mooted Shahani's appeal because it granted primary physical custody to Navani and prohibited returning the child to Shahani's custody. Shahani opposed the motion to dismiss, contending that the new custody order conflicted with English family law, and the English family court issued the new custody order without hearing argument from her counsel.

The Tenth Circuit pointed out that the mootness question necessarily constitutes its threshold inquiry, because the existence of a live case or controversy is a constitutional prerequisite to the jurisdiction of the federal courts.' " In re L.F. Jennings Oil Co., 4 F.3d 887, 888 (10th Cir.1993) (citation omitted). It has no authority " 'to give opinions upon moot questions or abstract propositions, or to declare principles or rules of law which cannot affect the matter in issue in the case before it.' " Church of Scientology v. United States, 506 U.S. 9, 12, 113 S.Ct. 447, 121 L.Ed.2d 313 (1992) (quoting Mills v. Green, 159 U.S. 651, 653, 16 S.Ct. 132, 40 L.Ed. 293 (1895)). A case or controversy must remain alive throughout the litigation, including on appellate review. Thournir v. Buchanan, 710 F.2d 1461, 1463 (10th Cir.1983) (citing Wiley v. Nat'l Collegiate Athletic Ass'n, 612 F.2d 473, 475 (10th Cir.1979) (en banc)). "[I]f an event occurs while a case is pending on appeal that makes it impossible for the court to grant 'any effectual relief whatever' to a prevailing party, the appeal must be dismissed." "The central question in determining whether a case has become moot is whether the issues presented are no longer live or the parties lack a legally cognizable interest in the outcome." Phelps v. Hamilton, 122 F.3d 885, 891 (10th Cir.1997).

The Tenth Circuit agreed with Navani that the new custody order prevented it from ordering any effectual relief in this appeal. If it concluded that the district court  should not have ordered Jivan's return to England because Navani failed to make his threshold showing that he possesses rights of custody over Jivan, the only way to remedy the error would be to order Jivan's return to the United States to be reunited with Navani. Yet the new custody order implicitly prohibited Jivan's return to the United States to live with his mother by forbidding "direct contact between the Applicant Mother and the child Jivan Navani outside the jurisdiction of England and Wales." The new custody order forbid Shahani from removing Jivan from his father's care and the jurisdiction of the English family court. Shahani could not even possess the travel documents, such as Jivan's passport, that would be necessary for international travel. Further, for it to decide Shahani's appeal it would have to determine whether Navani possessed rights of custody under the original custody order. But interpreting the rights of custody that the parties possessed under the original custody order would be a futile exercise because the new custody order discharged all prior custody orders. Finally, the new custody order made clear that contrary to Shahani's argument before the district court and on appeal that Navani had no rights of custody at the time of the alleged wrongful retention, Navani "has and had at all material times equal rights of custody together with the Mother in relation to Jivan, including at the time of his wrongful retention in the United States in September 2004."

The Tenth Circuit held that although the Full Faith and Credit Clause does not require us to recognize judgments, such as the new custody order, which are rendered in foreign countries, Soc'y of Lloyd's v. Reinhart, 402 F.3d 982, 994 (10th Cir.2005),  the new custody order should be given effect in American courts for two  reasons. First, general principles of comity normally counsel giving "considerable deference" to a foreign judgment. The English family court's interpretation of its domestic law--that Navani has always possessed rights of custody over Jivan  and that Shahani breached those rights of custody by wrongfully retaining Jivan in the United States–was therefore entitled to our respect. Second, and more fundamentally, factors unique to the Hague Convention suggest that the English family court should be given the final word, through the new custody order, in this matter. Both the letter and spirit of the Hague Convention suggested that the new custody order ends this matter. Neither party disputes that England was Jivan's country of habitual residence. As a result, the English family court had, and continues to have, plenary jurisdiction over Jivan's custody. The English family court retained its jurisdiction over custody regardless of whether the district court correctly decided the merits of the Hague Convention petition. Exercising its plenary jurisdiction, the English family court had determined that Shahani's custody rights do not extend to removing Jivan from England and returning him to the United States. As the court had no jurisdiction to determine the parties' custody rights over Jivan, it had to yield to the English family court's decision forbidding Shahani from removing Jivan to the United States. As a result, it could grant no effectual relief to Shahani.

Shahani asserted that the appeal was analogous to Whiting v. Krassner, 391 F.3d 540 (3d Cir.2004) cert. denied, 545 U.S. 1131, 125 S.Ct. 2938, 162 L.Ed.2d 871 (2005), and Fawcett v. McRoberts, 326 F.3d 491 (4th Cir.2003), in which the Third and Fourth Circuits concluded that an appeal of an order granting a Hague Convention petition is not mooted by the child's return to his country of habitual residence during the pendency of the appeal. In Fawcett, whose logic the Third Circuit substantially adopted, the Fourth Circuit explained that it retained the power to grant meaningful relief because the district court could order the child's return to the United States following a reversal and remand. Furthermore, it noted (because the case involved Scottish law) that the courts of the United Kingdom are required by statute to recognize another contracting state's Hague Convention orders--meaning that if a federal court of appeals reversed a district court's granting of a return petition, the courts of the United Kingdom would recognize that reversal and provide for the child's return to the United States. Finally, even if the United Kingdom was not so solicitious of a foreign court's orders, an American court could still find a non-complying petitioner in contempt. Even if Fawcett and Whiting were correct that a child's return to his country of habitual residence fails to moot an appeal--an issue it did not reach in this case --Shahani's appeal differed from Fawcett and Whiting in one critical aspect: Shahani's appeal became moot as a result of the terms of the new custody order, not the mere fact of Jivan's return to England. Assuming that it had the power to alter the status quo, prior to the issuance of the new custody order, by ordering Jivan's return to the United States, it lost that authority once the English family court altered the terms of the child's custody to forbid Jivan from traveling to the United States to have contact with his mother. As the English family court retained jurisdiction at all times over Jivan's custody, and we have never had jurisdiction over the merits of the English family court's custodial decisions, the court was powerless to alter the current custodial regime forbidding the very relief that Shahani sought: return of the child to the United States.