Both courts may “act[] only with respect to matters of law.” 10 U.S.C. § 867(c); see 10 U.S.C. § 950g(b) (same). And, as we have explained, the authority of the court of appeals to consider whether the military commission decision is “consistent with the standards and procedures” of the MCA, with the “laws of the United States,” and with “the Constitution” (10 U.S.C. § 950g(c)) allows the sort of “plenary review” of legal issues to which the Hamdan majority spoke.