concurring.
The various views presented in the opinions in these cases reflect the unusual procedural posture of the cases and the difficulties inherent in allocating the burdens of recession and fiscal austerity. I concur in the Court’s treatment of these *584difficult issues, and write separately to reflect my understanding of what the Court holds today.
I
To appreciate the Court’s disposition of the mootness issue, it is necessary to place these cases in their complete procedural perspective. The parties agree that the District Court and the Court of Appeals were presented with a “case or controversy” in every sense contemplated by Art. Ill of the Constitution. Respondents, as trial-plaintiffs, initiated the dispute, asking the District Court preliminarily to enjoin the City from reducing the percentage of minority employees in various job classifications within the Fire Department. Petitioners actively opposed that motion, arguing that respondents had waived any right to such relief in the consent decree itself and, in any event, that the reductions-in-force were bona fide applications of the citywide seniority system. When the District Court held against them, petitioners followed the usual course of obeying the injunction and prosecuting an appeal. They were, however, unsuccessful on that appeal.
Respondents now claim that the cases have become moot on certiorari to this Court. The recession is over, the employees who were laid off or demoted have been restored to their former jobs, and petitioners apparently have no current need to make seniority-based layoffs. The res judicata effects of the District Court’s order can be eliminated by the Court's usual practice of vacating the decision below and remanding with instructions to dismiss. See United States v. Munsingwear, Inc., 340 U. S. 36, 39 (1950). Thus, respondents conclude that the validity of the preliminary injunction is no longer an issue of practical significance and the cases can be dismissed as moot. See Brief for Respondents 26-28.
I agree with the Court that petitioners and respondents continue to wage a controversy that would not be resolved by merely vacating the preliminary injunction. As a result of *585the District Court’s order, several black employees have more seniority for purposes of future job decisions and entitlements than they otherwise would have under the City’s seniority system. This added seniority gives them an increased expectation of future promotion, an increased priority in bidding on certain jobs and job transfers, and an increased protection from future layoffs. These individuals, who are members of the respondent class, have not waived their increased seniority benefits. Therefore, petitioners have a significant interest in determining those individuals’ claims in the very litigation in which they were originally won. As the Court of Appeals noted, if petitioner-employer does not vigorously defend the implementation of its seniority system, it will have to cope with deterioration in employee morale, labor unrest, and reduced productivity. See 679 F. 2d 541, 555, and n. 12 (CA6 1982); see also Ford Motor Co. v. EEOC, 458 U. S. 219, 229 (1982). Likewise, if petitioner-union accedes to discriminatory employment actions, it will lose both the confidence of its members and bargaining leverage in the determination of who should ultimately bear the burden of the past (and future) fiscal shortages. See ante, at 571, and n. 5. Perhaps this explains why, in respondents’ words, “the city and union have expended substantial time and effort... in [an] appeal which can win no possible relief for the individuals on whose behalf it has ostensibly been pursued.” Brief for Respondents 44.
When collateral effects of a dispute remain and continue to affect the relationship of litigants,1 the case is not moot. *586See, e. g., Franks v. Bowman Transportation Co., 424 U. S. 747, 755-757 (1976); Super Tire Engineering Co. v. McCorkle, 416 U. S. 115, 121-125 (1974); Gray v. Sanders, 372 U. S. 368, 375-376 (1963). In such cases, the Court does not hesitate to provide trial defendants with “a definitive disposition of their objections” on appeal, Pasadena City Bd. of Education v. Spangler, 427 U. S. 424, 440 (1976), because vacating the res judicata effects of the decision would not bring the controversy to a close. See Note, Mootness on Appeal in the Supreme Court, 83 Harv. L. Rev. 1672, 1677-1687 (1970). As the Court wisely notes, “[litigants] cannot invoke the jurisdiction of a federal court. . . and then insulate [the effects of that court’s] ruling from appellate review by claiming that they are no longer interested in the matter.” Ante, at 572.
II
My understanding of the Court’s holding on the merits also is aided by a review of the place this case takes in the history of the parties’ litigation. The City entered into a consent decree with respondents, agreeing to certain hiring and promotional goals, backpay awards, and individual promotions. The City was party both to another consent decree and to an agreement with the union concerning application of the seniority system at the time it made these concessions. Respondents did not seek the union’s participation in the negotiation of their consent decree with the City, did not include the seniority system as a subject of negotiation, and waived all rights to seek further relief. When the current dispute arose, the District Court rejected respondents’ allegation that the seniority system had been adopted or applied with any discriminatory animus. It held, however, that “modification” was appropriate because of the seniority system’s discriminatory effects. Under these circumstances, the Court’s *587conclusion that the District Court had no authority to order maintenance of racial percentages in the Department is, in my view, inescapable.
Had respondents presented a plausible case of discriminatory animus in the adoption or application of the seniority system, then the Court would be hard pressed to consider entry of the preliminary injunction an abuse of discretion. But that is not what happened here. To the contrary, the District Court rejected the claim of discriminatory animus, and the Court of Appeals did not disagree. Furthermore, the District Court’s erroneous conclusion to the contrary, maintenance of racial balance in the Department could not be justified as a correction of an employment policy with an unlawful disproportionate impact. Title VII affirmatively protects bona fide seniority systems, including those with discriminatory effects on minorities. See American Tobacco Co. v. Patterson, 456 U. S. 63, 65 (1982); Teamsters v. United States, 431 U. S. 324, 352 (1977).
Therefore, the preliminary injunction could only be justified as a reasonable interpretation of the consent decree or as a permissible exercise of the District Court’s authority to modify that consent decree. Neither justification was present here. For the reasons stated by the Court, ante, at 574-576, and Justice Stevens, post, at 591, the consent decree itself cannot fairly be interpreted to bar use of the seniority policy or to require maintenance of racial balances previously achieved in the event layoffs became necessary. Nor can a district court unilaterally modify a consent decree to adjust racial imbalances or to provide retroactive relief that abrogates legitimate expectations of other employees and applicants. See Steelworkers v. Weber, 443 U. S. 193, 205-207 (1979); Pasadena City Bd. of Education v. Spangler, supra, at 436-438. A court may not grant preferential treatment to any individual or group simply because the group to which they belong is adversely affected by a bona fide seniority system. Rather, a court may use its remedial powers, including its power to modify a consent decree, only to pre*588vent future violations and to compensate identified victims of unlawful discrimination. See Teamsters v. United States, supra, at 367-371; Milliken v. Bradley, 433 U. S. 267, 280-281 (1977); see also University of California Regents v. Bakke, 438 U. S. 265, 307-309, and n. 44 (1978) (Powell, J., announcing the judgment of the Court). Even when its remedial powers are properly invoked, a district court may award preferential treatment only after carefully balancing the competing interests of discriminatees, innocent employees, and the employer. See Ford Motor Co. v. EEOC, 458 U. S., at 239-240; Teamsters v. United States, supra, at 371-376. In short, no matter how significant the change in circumstance, a district court cannot unilaterally modify a consent decree to adjust racial balances in the way the District Court did here.2
To be sure, in 1980, respondents could have gone to trial and established illegal discrimination in the Department’s past hiring practices, identified its specific victims, and possibly obtained retroactive seniority for those individuals. Alternatively, in 1980, in negotiating the consent decree, respondents could have sought the participation of the union,3 negotiated the identities of the specific victims with the union and employer, and possibly obtained limited forms of retroactive relief. But respondents did none of these things. They chose to avoid the costs and hazards of litigating their claims. They negotiated with the employer without inviting the union’s participation. They entered into a consent decree *589without establishing any specific victim’s identity. And, most importantly, they waived their right to seek further relief. To allow respondents to obtain relief properly reserved for only identified victims or to prove their victim status now would undermine the certainty of obligation that is a condition precedent to employers’ acceptance of, and unions’ consent to, employment discrimination settlements. See Steelworkers v. Weber, supra, at 211 (Blackmun, J., concurring) (employers enter into settlements to avoid backpay responsibilities and to reduce disparate impact claims). Modifications requiring maintenance of racial balance would not encourage valid settlements4 of employment discrimination cases. They would impede them. Thus, when the Court states that this preferential relief could not have been awarded even had this case gone to trial, see ante, at 579, it is holding respondents to the bargain they struck during the consent decree negotiations in 1980 and thereby furthering the statutory policy of voluntary settlement. See Carson v. American Brands, Inc., 450 U. S. 79, 88, and n. 14 (1981).
In short, the Court effectively applies the criteria traditionally applicable to the review of preliminary injunctions. See Doran v. Salem Inn, Inc., 422 U. S. 922, 981 (1975). When the Court disapproves the preliminary injunction issued in this litigation, it does so because respondents had no chance of succeeding on the merits of their claim. The District Court had no authority to order the Department to maintain its current racial balance or to provide preferential *590treatment to blacks. It therefore abused its discretion. On this understanding, I join the opinion and judgment rendered by the Court today.
This case is distinguishable from University of Texas v. Camenisch, 451 U. S. 390 (1981), where the Court found that a petitioner’s objections to a preliminary injunction, which required it to pay for the respondent’s sign-language interpreter, were moot. In Camenisch, the propriety of issuing the preliminary injunction was really no longer of concern to the parties, and the real issue — who should pay for the interpreter — was better handled in a separate proceeding. Id., at 394-398. In these cases, because the parties are in an ongoing relationship, they have a continuing *586interest in the propriety of the preliminary relief itself. Camenisch expressly distinguishes cases like these, where the parties retain “a legally cognizable interest in the determination whether the preliminary injunction was properly granted.” Id., at 394; see also id., at 397, and n. 2.
Unlike the dissenters and Justice Stevens, I find persuasive the Court’s reasons for holding Title VII relevant to analysis of the modification issue, see ante, at 576-577, n. 9, and the Court’s application of Title VII’s provisions to the facts of the present controversy.
“Absent a judicial determination, . . . the Company . . . cannot alter the collective-bargaining agreement without the Union’s consent.” W. R. Grace & Co. v. Rubber Workers, 461 U. S. 757, 771 (1983)., Thus, if innocent employees are to be required to make any sacrifices in the final consent decree, they must be represented and have had full participation rights in the negotiation process.
The policy favoring voluntary settlement does not, of course, countenance unlawful discrimination against existing employees or applicants. See McDonald v. Santa Fe Trail Transportation Co., 427 U. S. 278, 278-296 (1976) (Title VII and 42 U. S. C. § 1981 prohibit discrimination against whites as well as blacks); Steelworkers v. Weber, 443 U. S. 193, 208-209 (1979) (listing attributes that would make affirmative action plan impermissible); cf. id., at 215 (Blackmun, J., concurring) (“[Seniority is not in issue because the craft training program is new and does not involve an abrogation of pre-existing seniority rights”).