delivered the opinion of the Court.
In 1978 respondent Sergio Mendoza, a Filipino national, filed a petition for naturalization under a statute which by its terms had expired 32 years earlier. 1 Respondent’s claim for naturalization was based on the assertion that the Government’s administration of the Nationality Act denied him due process of law. Neither the District Court nor the Court of Appeals for the Ninth Circuit ever reached the merits of his claim, because they held that the Government was collaterally estopped from litigating that constitutional issue in view of an earlier decision against the Government in a case brought by other Filipino nationals in the United States District Court for the Northern District of California. We hold that the United States may not be collaterally estopped on an issue such as this, adjudicated against it in an earlier lawsuit brought by a different party. We therefore reverse the judgment of the Court of Appeals.
Respondent Mendoza served as a doctor in the Philippine Commonwealth Army from 1941 until his discharge in 1946. Because Japanese occupation of the Philippines had made naturalization of alien servicemen there impossible before the liberation of the Islands, the INS did not designate a representative to naturalize eligible servicemen there until 1945. Because of concerns expressed by the Philippine Government to the United States, however, to the effect that large numbers of Filipinos would be naturalized and would immigrate to the United States just as the Philippines gained their independence, the Attorney General subsequently revoked the naturalization authority of the INS representative. Thus all naturalizations in the Philippines were halted for a 9-month period from late October 1945 until a new INS representative was appointed in August 1946.
Respondent’s claim for naturalization is based on the contention that that conduct of the Government deprived him of due process of law in violation of the Fifth Amendment to the United States Constitution, because he was present in the
Noting that the doctrine of nonmutual offensive collateral estoppel has been conditionally approved by this Court in
Parklane Hosiery Co.
v.
Shore,
Under the judicially developed doctrine of collateral estop-pel, once a court has decided an issue of fact or law necessary to its judgment, that decision is conclusive in a subsequent suit based on a different cause of action involving a party to the prior litigation.
Montana
v.
United States,
In
Standefer
v.
United States,
We have long recognized that “the Government is not in a position identical to that of a private litigant,”
INS
v.
Hibi,
A rule allowing nonmutual collateral estoppel against the Government in such cases would substantially thwart the development of important questions of law by freezing the first final decision rendered on a particular legal issue. Allowing only one final adjudication would deprive this Court of the benefit it receives from permitting several courts of appeals to explore a difficult question before this Court grants certiorari. See
E. I. du Pont de Nemours & Co.
v.
Train,
The Solicitor General’s policy for determining when to appeal an adverse decision would also require substantial revision.
6
The Court of Appeals faulted the Government in this caseN for failing to appeal a decision that it now contends is
In addition to those institutional concerns traditionally considered by the Solicitor General, the panoply of important public issues raised in governmental litigation may quite properly lead successive administrations of the Executive Branch to take differing positions with respect to the resolution of-a particular issue. While the Executive Branch must of course defer to the Judicial Branch for final resolution of questions of constitutional law, the former nonetheless controls the progress of Government litigation through the federal courts. It would be idle to pretend that the conduct of Government litigation in all its myriad features, from the decision to file a complaint in the United States district court to the decision to petition for certiorari to review a judgment of the court of appeals, is a wholly mechanical procedure which involves no policy choices whatever.
For example, in recommending to the Solicitor General in 1977 that the Government’s appeal in
68 Filipinos
be withdrawn, newly appointed INS Commissioner''Castillo commented that such a course “would be in keeping with the policy of the [new] Administration,” described as
“a
course of compassion and amnesty.” Brief for United States 11. But for the very reason that such policy choices are made by one administration, and often reevaluated by another administration, courts should be careful when they seek to apply expanding rules of collateral estoppel to Government litiga
The Court of Appeals did not endorse a routine application of nonmutual collateral estoppel against the Government, because it recognized that the Government does litigate issues of far-reaching national significance which in some cases, it concluded, might warrant relitigation. But in this case it found no “record evidence” indicating that there was a “crucial need” in the administration of the immigration laws for a redetermination of the due process question decided in
68 Filipinos
and presented again in this case.
We hold, therefore, that nonmutual offensive collateral es-toppel simply does not apply against the Government in such a way as to preclude relitigation of issues such as those involved in this case.
7
The conduct of Government litigation in
Our holding in this case is consistent with each of our prior holdings to which the parties have called our attention, and which we reaffirm. Today in a companion case we hold that the Government may be estopped under certain circumstances from relitigating a question when the parties to the two lawsuits are the same.
United States
v.
Stauffer Chemical Co., post,
p. 165; see also
Montana
v.
United States,
The concerns underlying our disapproval of collateral es-toppel against the Government are for the most part inappli
Reversed.
Notes
Mendoza sought naturalization pursuant to §§ 701-705 of the Nationality Act of 1940, 54 Stat. 1137, added by the Second War Powers Act, 1942, 56 Stat. 182, as amended, 8 U. S. C. §§1001-1005 (1940 ed., Supp. V).
In
68 Filipinos,
the District Court considered the naturalization petitions of 68 Filipino World War II veterans filed pursuant to §§ 701-702 of the Nationality Act. Fifty-three of those veterans, whom the District Court designated as Category II veterans, like Mendoza, had made no effort to become naturalized before the expiration of the statutory provisions. Like Mendoza, they claimed that the failure of the United States to station an INS representative in the Philippines for the entire period of time in which rights under § 702 were available to them discriminated against Filipinos as a class. Rejecting the Government’s arguments that
INS
v.
Hibi,
Although the Government initially docketed an appeal from that decision, the Court of Appeals granted the Government’s motion to withdraw the appeal on November 30, 1977. The Government made that motion after a new administration and a new INS Commissioner had taken office. Eventually the Government reevaluated its position and decided to take appeals from all orders granting naturalization to so-called Category II petitioners, with the exception of orders granting naturalization to petitioners who filed petitions prior to the withdrawal of the appeal in
68 Filipinos.
Brief for United States 11-12, and n. 13;
Olegario
v.
United States,
Under res judicata, a final judgment on the merits bars further claims by parties or their privies on the same cause of action.
Montana
v.
United States,
Offensive use of collateral estoppel occurs when a plaintiff seeks to foreclose a defendant from relitigating an issue the defendant has previously litigated unsuccessfully in another action against the same or a different party. Defensive use of collateral estoppel occurs when a defendant seeks to prevent a plaintiff from relitigating an issue the plaintiff has previously litigated unsuccessfully in another action against the same or a different party. Parklane Hosiery, supra, at 326, n. 4.
In Montana we held that the Government was estopped from relitigat-ing in federal court the constitutionality of Montana’s gross receipts tax on contractors of public construction firms. That issue had previously been litigated in state court by an individual contractor whose litigation had been totally financed and controlled by the Federal Government. Montana v. United States, supra, at 151, 155; see n. 9, infra.
The Attorney General has delegated discretionary authority to the Solicitor General to determine when to appeal from a judgment adverse to the interests of the United States. 28 CFR § 0.20(b) (1983).
The Government does not base its argument on the exception to the doctrine of collateral estoppel for “unmixed questions of law” arising in “successive actions involving unrelated subject matter.”
Montana
v.
In
Nevada
v.
United States,
In
Montana
an individual contractor brought an initial action to challenge Montana’s gross receipts tax in state court, and the Federal Government brought a second action in federal court raising the same challenge. The Government totally controlled and financed the state-court action; thus for all practical purposes, there was mutuality of parties in the two cases. “[T]he United States plainly had a sufficient ‘laboring oar’ in the conduct of the state-court litigation,”
