Mr. Justice Stewart,
with whom The Chief Justice, Mr. Justice Powell, and Mr. Justice Rehwquist join,dissenting.
The respondent's predecessor, Continental, made corporate acquisitions in violation of a 1962 consent order that, in pertinent part, prohibited Continental from “acquiring” described baking companies. The Government *244sought to impose daily penalties upon Continental for the continued holding of those assets. The Government’s theory was that daily penalties were appropriate because Continental’s retention of the assets was a “continuing failure or neglect to obey a final order,” within the meaning of the relevant civil penalties statutes, 15 U. S. C. §§ 21 (£), 45 (l).1 The issue in this case is whether the consent order can be so construed.2 The District Court and the Court of Appeals ruled that the consent order prohibited only the distinct acts of “acquiring” the bakeries, not the “retaining” or the “holding” of the assets after acquisition. The Court of Appeals indicated that an order to divest would have been an appropriate remedy for the unlawful acquisitions, but held that the retention of the assets was not in itself a continuing refusal to obey the consent order such as would support the sanction of daily penalties. I think that under our controlling precedents, the District Court and-the Court of Appeals were clearly correct.
The governing rule of construction, and its rationale, were stated plainly and aptly by this Court in United States v. Armour & Co., 402 U. S. 673, 681-682 (1971):
“Consent decrees are entered into by parties to a case after careful negotiation has produced agreement on their precise terms. The parties waive their right to litigate the issues involved in the case and thus save themselves the time, expense, and inevitable risk of litigation. Naturally, the agreement reached normally embodies a compromise; in exchange for the saving of cost and elimination of risk, *245the parties each give up something they might have won had they proceeded with the litigation. Thus the decree itself cannot be said to have a purpose; rather the parties have purposes, generally opposed to each other, and the resultant decree embodies as much of those opposing purposes as the respective parties have the bargaining power and skill to achieve. For these reasons, the scope of a consent decree must be discerned within its four corners, and not by reference to what might satisfy the purposes of one of the parties to it. Because the defendant has, by the decree, waived his right to litigate the issues raised, a right guaranteed to him by the Due Process Clause, the conditions upon which he has given that waiver must be respected, and the instrument must be construed as it is written, and not as it might have been written had the plaintiff established his factual claims and legal theories in litigation.” (Emphasis added; footnote omitted.)
See also United States v. Atlantic Refining Co., 360 U. S. 19 (1959); Hughes v. United States, 342 U. S. 353 (1952).
The application of this straightforward standard to the consent order here is hardly a difficult task. The order literally prohibits only the “acquiring” of the forbidden assets. Once an acquisition was consummated, the violation was complete. A prohibition on the retention of assets cannot be found in any provision of the order. Because the order is a compromise agreement negotiated without any adjudication of antitrust liability, we are not at liberty under Armour to construe the unambiguous term “acquiring” in the light of conjecture or argument about the “purposes” of the decree or of the parties. We may not, consistent with Armour, conclude that the Government intended that the order should prohibit as a continuing offense the retention of unlawfully acquired *246assets, when the Government did not insist upon language objectively manifesting that intention. Nor may we conclude that Continental agreed to restrict its future business conduct or become subject to penalties in any manner not clearly delineated in the order itself. The provisions of the order are something less than the Government could have sought and might have obtained. The rule of construction of consent decrees, however, depends, not upon an expedient construct of what the parties are thought to ha-ve intended, but upon the explicit provisions to which the parties have agreed.
After giving a casual nod in the direction of the standard of construction required by Armour, the Court embarks upon a laborious search for “purposes” that are “incorporated in” the consent order in order to change the meaning of the unambiguous term “acquiring.” We are led through the antecedent complaint, through an appendix to the consent order, through the intricacies of an opinion of this Court construing the term “acquisition” in light of the policies underlying the Clayton Act, and through the legislative history of the statutory provisions that impose daily penalties for continuing refusals to obey Commission orders. Drawing upon these disparate sources, the Court determines that the consent order, despite its literal language, must be construed to prohibit not only the proscribed acquisitions but also the “retention” of unlawfully acquired assets.3 One is re*247minded of an observation once made by Mr. Justice Grier in a somewhat different context: “[T]he fact that it required so ingenious and labored an argument by my learned brother to vindicate such a construction . .. seems to me, of itself, conclusive evidence that the construction should not be given to it.” The Binghamton Bridge, 3 Wall. 51, 83 (dissenting opinion).
What the Court does today is to proclaim a new rule of construction for consent orders or decrees totally at odds with our previous decisions:
“Since a consent decree or order is to be construed for enforcement purposes basically as a contract, reliance upon certain aids to construction is proper, as with any other contract. Such aids include the circumstances surrounding the formation of the consent order, any technical meaning words used may have had to the parties, and any other documents expressly incorporated in the decree.” Ante, at 238.
This novel approach, for which the Court cites not a single supporting precedent, is directly contrary to the “four corners” rule of Armour. For an inquiry into the purpose of a consent decree is precisely what that rule forecloses: “[T]he scope of a consent decree must be discerned within its four corners, and not by reference to what might satisfy the purposes of one of the parties to it.” 402 U. S., at 682. The Court today thus indulges in precisely the exercise that Armour sought to preclude: *248a wide-ranging search for a “purpose” in a decree that, as explained in Armour, cannot be said to have a purpose except to delineate explicitly the terms and provisions of the settlement that the parties negotiated.4
Before straining to pull the Government’s chestnuts out of the fire, the Court should count with greater care the costs of abandoning the rule stated in Armour. Until today, the parties to any consent decree could have confidence that its explicit terms alone would control the judicial construction of its prohibitory language. Now, otherwise unambiguous terms of a consent decree may be construed in light of such considerations as the ante*249cedent complaint, the “meaning” of antitrust decisions, and the policies said to underlie the statutory provision for daily penalties. Certainty and reasoned reliance have always been the sine qua non of the consent orders that terminate about 70% to 80% of the antitrust complaints that are filed by the Justice Department.5 But after today’s decision that kind of certainty will no longer exist. For there will be no apparent limit on the power of the judiciary to alter the plain language of an order in light of the “circumstances surrounding the order and the context in which the parties were operating.” Ante, at 243. If a negotiated consent decree fails to leave a dispute clearly and firmly settled, the necessary result will be that those charged with antitrust violations will be less inclined to settle their cases and more apt to insist upon time-consuming and costly litigation. Today’s decision will also pose serious difficulties for the enforcement of all existing and all future consent decrees. For, as Mr. Justice Jackson once observed, “the validity of a doctrine does not depend on whose ox it gores.” 6 The same purpose-oriented techniques of construction that the Court today serves up to expand this consent order beyond its terms can be expected to be availed of by alleged violators of consent orders who will seek to narrow and thereby to evade the plain language of any prohibition.
The Court concludes that “if violation of an order prohibiting 'acquiring’ assets were treated as a single violation, any deterrent effect of the penalty provisions would be entirely undermined, and the penalty would be converted into a minor tax upon a violation which could reap large financial benefits to the perpetrator.” Ante, *250at 232. This is not merely overstatement; it is incorrect. Both the parties agree, and the Court of Appeals held, that an order to divest unlawfully acquired assets is an appropriate remedy for violation of a consent order barring acquisition. Moreover, the Armour rule of construction would not impair in any way the power of the Government, in future cases, to obtain through negotiations consent orders that contain a clear and explicit description of the conduct that is prohibited.7
In my view, the Court’s departure from precedent threatens to retard significantly the effective use of consent decrees in the administration of the antitrust laws. I would adhere to the rule stated in Armour that “the scope of a consent decree must be discerned within its four corners, and not by reference to what might satisfy the purposes of one of the parties to it.” 402 U. S., at 682 (emphasis added). Applying this standard, I would affirm the considered judgments of the District Court and the Court of Appeals.
These provisions are set out in full in the Court's opinion, ante, at 228-229, nn. 5, 6.
For the reasons stated by the Court, I agree that the other issues that the respondent seeks to raise in this case need not and should not be addressed.
Upon this premise, the Court then proceeds to hold that the conjured-up “continuing offense” of retaining these assets is a “continuing failure or neglect to obey a final order” within the meaning of the daily-penalty statutes. 15 U. S. C. §§21 (l) and 45 (l). But even if the consent order could be correctly read to prohibit not only the acquisition of the described assets but also the retention of assets unlawfully acquired, it is far from crystal clear that the “continuing offense” of retaining the assets would be a “continuing failure or neglect to obey a final order” within the meaning of the *247daily-penalty statutes. Penalty provisions must be strictly construed, and due process requires that such provisions must give fair warning of the conduct that invokes their extraordinary sanction. Cf. Giaccio v. Pennsylvania, 382 U. S. 399. The legislative history of the daily-penalty statutes, as recited in the Court’s opinion, shows that the mischief sought to be remedied was precisely the mischief to which Congress addressed its language: a “continuing failure or neglect to obey a final order,” as, for example, the refusal to divest after a specific order of divestiture has been entered.
Whatever the utility of extrinsic aids in construing a typical commercial contract, this technique is singularly inappropriate in an area where certainty of prohibition is necessary and where, as Armour makes clear, there can be found no guiding purpose underlying a negotiated decree. Moreover, even assuming, arguendo, that such aids might be admissible to construe borderline issues of application — for example, whether a particular acquired company was engaged in the production of "bread-type” rolls within the meaning of the consent order — such aids must not be used to impose a wholly separate prohibitory requirement upon a company that consented to be bound only by the plain language of the consent order. This is demonstrably not a caso of ambiguity or of borderline construction. It is a case, instead, where the Court has used extrinsic aids to alter a term that is, on its face, wholly unambiguous.
The Court relies upon the decision in United States v. Du Pont, 353 U. S. 586, for the proposition that the term "acquire” in a consent order is a term of art that prohibits a “status which continues until the transaction is undone.” Ante, at 242. But the Court’s reliance on the policy considerations discussed in the Du Pont opinion is wholly inconsistent with the Armour rule. The opinion in United States v. Du Pont does not, in any event, render the term “acquiring” in a consent decree a term of art. That case addressed the positive reach of the Clayton Act under certain circumstances. The Court fails to explain how its opinion there has served to transform the plain term “acquiring” into a “term of art” that would by common understanding have the meaning that the Court today ascribes to it.
Note, 73 Col. L. Rev. 594 (1973).
Wells v. Simonds Abrasive Co., 345 U. S. 514, 525 (dissenting opinion).
The Government informs us that as of May 1974 there were outstanding 54 consent orders with language that prohibits acquiring certain assets but does not expressly prohibit the retaining of these assets. This Court, need not assume that flagrant violations of consent orders will occur or that the remedies of divestiture and fine for the single offense of acquisition will not adequately deter unlawful conduct.