Page:United States Reports, Volume 542.djvu/430

Rh by principles similar to those we have outlined, supra, at 380–382, that limit the Court of Appeals' use of the remedy. The panel majority, however, failed to ask this question. Instead, it labored under the mistaken assumption that the assertion of executive privilege is a necessary precondition to the Government's separation of powers objections.

In the absence of overriding concerns of the sort discussed in Schlagenhauf, 379 U.S., at 111 (discussing, among other things, the need to avoid "piecemeal litigation" and to settle important issues of first impression in areas where this Court bears special responsibility), we decline petitioners' invitation to direct the Court of Appeals to issue the writ against the District Court. Moreover, this is not a case where, after having considered the issues, the Court of Appeals abused its discretion by failing to issue the writ. Instead, the Court of Appeals, relying on its mistaken reading of United States v. Nixon, prematurely terminated its inquiry after the Government refused to assert privilege and did so without even reaching the weighty separation of powers objections raised in the case, much less exercised its discretion to determine whether "the writ is appropriate under the circumstances." Supra, at 381. Because the issuance of the writ is a matter vested in the discretion of the court to which the petition is made, and because this Court is not presented with an original writ of mandamus, see, e. g., Ex parte Peru, 318 U.S., at 586, we leave to the Court of Appeals to address the parties' arguments with respect to the challenge to AAPS and the discovery orders. Other matters bearing on whether the writ of mandamus should issue should also be addressed, in the first instance, by the Court of Appeals after considering any additional briefs and arguments as it deems appropriate. We note only that all courts should be mindful of the burdens imposed on the Executive Branch in any future proceedings. Special