disposes of all of plaintiffs’ claims, direct or derivative. Whether a suit falls within the exception is a threshold question of subject-matter jurisdiction. See, e.g., Tippett v. United States, 108 F.3d 1194, 1196-97 (10th Cir.1997); Daigle v. Shell Oil Co., 972 F.2d 1527, 1537 (10th Cir.1992). Neither party suggests that the inquiry differs if the suit is direct or derivative. Only if this court were to hold that there is subject-matter jurisdiction under the FTCA, or under another waiver of immunity, would we have to decide whether Kansas law entitles plaintiffs to sue directly, derivatively, or neither. This is true even if we also deem the latter questions 'jurisdictional.” See Arizonans for Official English v. Arizona, 520 U.S. 43, 66-67, 117 S.Ct. 1055, 137 L.Ed.2d 170 (1997) (<HOLDING>); Cross-Sound Ferry Servs., Inc., v. ICC, 934
holding that article iii standing is necessary for intervention holding that article iii standing is not a prerequisite to intervention holding that court may assume standing despite grave doubts in order to decide mootness as both questions concern article iii jurisdiction not the merits holding that federal courts may not consider other issues before resolving standing an article iii jurisdictional matter recognizing that while in a diversity case a federal court may not address the plaintiffs claim unless the plaintiff has standing to sue under state law the plaintiff must also meet article iii standing requirements