JUSTICE REHNQUIST delivered the opinion of the Court.

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[1] We are confined to a resolution of the dispute presented to us. That dispute involves various Executive Orders and regulations by which the President nullified attachments and liens on Iranian assets in the United States, directed that these assets be transferred to Iran, and suspended claims against Iran that may be presented to an International Claims Tribunal. This action was taken in an effort to comply with an Executive Agreement between the United States and Iran.

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I

[2] On November 4, 1979, the American Embassy in Tehran was seized and our diplomatic personnel were captured and held hostage. In response to that crisis, President Carter, acting pursuant to the International Emergency Economic Powers Act, 91 Stat. 1626, 50 U. S. C. §§ 1701-1706 (1976 ed., Supp. III) (hereinafter IEEPA), declared a national emergency on November 14, 1979, and blocked the removal or transfer of “all property and interests in property of the Government of Iran, its instrumentalities and controlled entities and the Central Bank of Iran which are or become subject to the jurisdiction of the United States . . . .” Exec. Order No. 12170

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[3] On December 19, 1979, petitioner Dames & Moore filed suit in the United States District Court for the Central District of California against the Government of Iran, the Atomic Energy Organization of Iran, and a number of Iranian banks. In its complaint, petitioner alleged that its wholly owned subsidiary, Dames & Moore International, S. R. L., was a party to a written contract with the Atomic Energy Organization, and that the subsidiary’s entire interest in the contract had been assigned to petitioner. Under the contract, the subsidiary was to conduct site studies for a proposed nuclear power plant in Iran. As provided in the terms of the contract, the Atomic Energy Organization terminated the agreement for its own convenience on June 30, 1979. Petitioner contended, however, that it was owed $3,436,694.30 plus interest for services performed under the contract prior to the date of termination. The District Court issued orders of attachment directed against property of the defendants, and the property of certain Iranian banks was then attached to secure any judgment that might be entered against them.

[4] On January 20, 1981, the Americans held hostage were released by Iran pursuant to an Agreement entered into the day before and embodied in two Declarations of the Democratic and Popular Republic of Algeria. Declaration of the Government of the Democratic and Popular Republic of Algeria (App. to Pet. for Cert. 21-29), and Declaration of the Government of the Democratic and Popular Republic of Algeria. . . The Agreement stated that “[i]t is the purpose of [the United States and Iran] . . . to terminate all litigation as between the Government of each party and the nationals of the other, and to bring about the settlement and termination of all such claims through binding arbitration.” Id., at 21-22. In furtherance of this goal, the Agreement called for the establishment of an Iran-United States Claims Tribunal which would arbitrate any claims not settled within six months. Awards of the Claims Tribunal are to be “final and binding” and “enforceable. . . in the courts of any nation in accordance with its laws.” Id., at 32.

[5] Under the Agreement, the United States is obligated “to terminate all legal proceedings in United States courts involving claims of United States persons and institutions against Iran and its state enterprises, to nullify all attachments and judgments obtained therein, to prohibit all further litigation based on such claims, and to bring about the termination of such claims through binding arbitration.” Id., at 22.

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[6] On February 24, 1981, President Reagan issued an Executive Order in which he “ratified” the January 19th Executive Orders [ of President Carter]. Moreover, he “suspended” all “claims which may be presented to the . . . Tribunal” and provided that such claims “shall have no legal effect in any action now pending in any court of the United States.”

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[7] On April 28, 1981, petitioner filed this action in the District Court for declaratory and injunctive relief against the United States and the Secretary of the Treasury, seeking to prevent enforcement of the Executive Orders and Treasury Department regulations implementing the Agreement with Iran. In its complaint, petitioner alleged that the actions of the President and the Secretary of the Treasury implementing the Agreement with Iran were beyond their statutory and constitutional powers and, in any event, were unconstitutional to the extent they adversely affect petitioner’s final judgment against the Government of Iran and the Atomic Energy Organization, its execution of that judgment in the State of Washington, its prejudgment attachments, and its ability to continue to litigate against the Iranian banks.

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II

[8] The parties and the lower courts, confronted with the instant questions, have all agreed that much relevant analysis is contained in [Youngstown].

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[9] Although we have in the past found and do today find Justice Jackson’s classification of executive actions into three general categories analytically useful, we should be mindful of Justice Holmes’ admonition, quoted by Justice Frankfurter in Youngstown, supra, at 597 (concurring opinion), that “[t]he great ordinances of the Constitution do not establish and divide fields of black and white.” Justice Jackson himself recognized that his three categories represented “a somewhat over-simplified grouping,” 343 U. S., at 635, and it is doubtless the case that executive action in any particular instance falls, not neatly in one of three pigeonholes, but rather at some point along a spectrum running from explicit congressional authorization to explicit congressional prohibition. This is particularly true as respects cases such as the one before us, involving responses to international crises the nature of which Congress can hardly have been expected to anticipate in any detail.

III

[10] In nullifying post-November 14, 1979, attachments and directing those persons holding blocked Iranian funds and securities to transfer them to the Federal Reserve Bank of New York for ultimate transfer to Iran, President Carter cited five sources of express or inherent power. The Government, however, has principally relied on § 203 of the IEEPA, 91 Stat. 1626, 50 U. S. C. § 1702 (a) (1) (1976 ed., Supp. III), as authorization for these actions. Section 1702 (a) (1) provides in part:

[11] “At the times and to the extent specified in section 1701 of this title, the President may, under such regulations as he may prescribe, by means of instructions, licenses, or otherwise—

[12] “(A) investigate, regulate, or prohibit—

[13] “(i) any transactions in foreign exchange,

[14] “(ii) transfers of credit or payments between, by, through, or to any banking institution, to the extent that such transfers or payments involve any interest of any foreign country or a national thereof,

[15] “(iii) the importing or exporting of currency or securities, and

[16] “(B) investigate, regulate, direct and compel, nullify, void, prevent or prohibit, any acquisition, holding, withholding, use, transfer, withdrawal, transportation, importation or exportation of, or dealing in, or exercising any right, power, or privilege with respect to, or transactions involving, any property in which any foreign country or a national thereof has any interest;

[17] “by any person, or with respect to any property, subject to the jurisdiction of the United States.”

[18] The Government contends that the acts of “nullifying” the attachments and ordering the “transfer” of the frozen assets are specifically authorized by the plain language of the above statute. The two Courts of Appeals that have considered the issue agreed with this contention.

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[19] Petitioner contends that we should ignore the plain language of this statute because an examination of its legislative history as well as the history of § 5 (b) of the Trading With the Enemy Act (hereinafter TWEA), from which the pertinent language of § 1702 is directly drawn, reveals that the statute was not intended to give the President such extensive power over the assets of a foreign state during times of national emergency. According to petitioner, once the President instituted the November 14, 1979, blocking order, § 1702 authorized him “only to continue the freeze or to discontinue controls.” Brief for Petitioner 32.

[20] We do not agree and refuse to read out of § 1702 all meaning to the words “transfer,” “compel,” or “nullify.” Nothing in the legislative history of either § 1702 or § 5 (b) of the TWEA requires such a result. To the contrary, we think both the legislative history and cases interpreting the TWEA fully sustain the broad authority of the Executive when acting under this congressional grant of power. See, e. g., Orvis v. Brownell, 345 U. S. 183 (1953).

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[21] This Court has previously recognized that the congressional purpose in authorizing blocking orders is “to put control of foreign assets in the hands of the President . . . .” Propper v. Clark, 337 U. S. 472, 493 (1949).

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[22] Because the President’s action in nullifying the attachments and ordering the transfer of the assets was taken pursuant to specific congressional authorization, it is “supported by the strongest of presumptions and the widest latitude of judicial interpretation, and the burden of persuasion would rest heavily upon any who might attack it.” Youngstown, 343 U. S., at 637 (Jackson, J., concurring). Under the circumstances of this case, we cannot say that petitioner has sustained that heavy burden. A contrary ruling would mean that the Federal Government as a whole lacked the power exercised by the President, see id., at 636-637, and that we are not prepared to say.

IV

[23] Although we have concluded that the IEEPA constitutes specific congressional authorization to the President to nullify the attachments and order the transfer of Iranian assets, there remains the question of the President’s authority to suspend claims pending in American courts. Such claims have, of course, an existence apart from the attachments which accompanied them. In terminating these claims through Executive Order No. 12294, the President purported to act under authority of both the IEEPA and 22 U. S. C. § 1732, the so-called “Hostage Act.” 46 Fed. Reg. 14111 (1981).

[24] We conclude that although the IEEPA authorized the nullification of the attachments, it cannot be read to authorize the suspension of the claims.

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[25] The Hostage Act, passed in 1868, provides:

[26] “Whenever it is made known to the President that any citizen of the United States has been unjustly deprived of his liberty by or under the authority of any foreign government, it shall be the duty of the President forthwith to demand of that government the reasons of such imprisonment; and if it appears to be wrongful and in violation of the rights of American citizenship, the President shall forthwith demand the release of such citizen, and if the release so demanded is unreasonably delayed or refused, the President shall use such means, not amounting to acts of war, as he may think necessary and proper to obtain or effectuate the release; and all the facts and proceedings relative thereto shall as soon as practicable be communicated by the President to Congress.” Rev. Stat. § 2001, 22 U. S. C. § 1732.

[27] We are reluctant to conclude that this provision constitutes specific authorization to the President to suspend claims in American courts. Although the broad language of the Hostage Act suggests it may cover this case, there are several difficulties with such a view. The legislative history indicates that the Act was passed in response to a situation unlike the recent Iranian crisis. Congress in 1868 was concerned with the activity of certain countries refusing to recognize the citizenship of naturalized Americans traveling abroad, and repatriating such citizens against their will.

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[28] The legislative history is also somewhat ambiguous on the question whether Congress contemplated Presidential action such as that involved here or rather simply reprisals directed against the offending foreign country and its citizens.

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[29] Although we have declined to conclude that the IEEPA or the Hostage Act directly authorizes the President’s suspension of claims for the reasons noted, we cannot ignore the general tenor of Congress’ legislation in this area in trying to determine whether the President is acting alone or at least with the acceptance of Congress. As we have noted, Congress cannot anticipate and legislate with regard to every possible action the President may find it necessary to take or every possible situation in which he might act. Such failure of Congress specifically to delegate authority does not, “especially. . . in the areas of foreign policy and national security,” imply “congressional disapproval” of action taken by the Executive. Haig v. Agee, ante, at 291. On the contrary, the enactment of legislation closely related to the question of the President’s authority in a particular case which evinces legislative intent to accord the President broad discretion may be considered to “invite” “measures on independent presidential responsibility,” Youngstown, 343 U. S., at 637 (Jackson, J., concurring). At least this is so where there is no contrary indication of legislative intent and when, as here, there is a history of congressional acquiescence in conduct of the sort engaged in by the President. It is to that history which we now turn.

[30] Not infrequently in affairs between nations, outstanding claims by nationals of one country against the government of another country are “sources of friction” between the two sovereigns. United States v. Pink, 315 U. S. 203, 225 (1942). To resolve these difficulties, nations have often entered into agreements settling the claims of their respective nationals. As one treatise writer puts it, international agreements settling claims by nationals of one state against the government of another “are established international practice reflecting traditional international theory.” L. Henkin, Foreign Affairs and the Constitution 262 (1972). Consistent with that principle, the United States has repeatedly exercised its sovereign authority to settle the claims of its nationals against foreign countries. Though those settlements have sometimes been made by treaty, there has also been a longstanding practice of settling such claims by executive agreement without the advice and consent of the Senate. Under such agreements, the President has agreed to renounce or extinguish claims of United States nationals against foreign governments in return for lump-sum payments or the establishment of arbitration procedures. To be sure, many of these settlements were encouraged by the United States claimants themselves, since a claimant’s only hope of obtaining any payment at all might lie in having his Government negotiate a diplomatic settlement on his behalf. But it is also undisputed that the “United States has sometimes disposed of the claims of its citizens without their consent, or even without consultation with them, usually without exclusive regard for their interests, as distinguished from those of the nation as a whole.” Henkin, supra, at 262-263. Accord, Restatement (Second) of Foreign Relations Law of the United States § 213 (1965) (President “may waive or settle a claim against a foreign state . . . [even] without the consent of the [injured] national”). It is clear that the practice of settling claims continues today. Since 1952, the President has entered into at least 10 binding settlements with foreign nations, including an $80 million settlement with the People’s Republic of China.

[31] Crucial to our decision today is the conclusion that Congress has implicitly approved the practice of claim settlement by executive agreement. This is best demonstrated by Congress’ enactment of the International Claims Settlement Act of 1949, 64 Stat. 13, as amended, 22 U. S. C. § 1621 et seq. (1976 ed. and Supp. IV). The Act had two purposes: (1) to allocate to United States nationals funds received in the course of an executive claims settlement with Yugoslavia, and (2) to provide a procedure whereby funds resulting from future settlements could be distributed. To achieve these ends Congress created the International Claims Commission, now the Foreign Claims Settlement Commission, and gave it jurisdiction to make final and binding decisions with respect to claims by United States nationals against settlement funds. 22 U. S. C. § 1623 (a). By creating a procedure to implement future settlement agreements, Congress placed its stamp of approval on such agreements. Indeed, the legislative history of the Act observed that the United States was seeking settlements with countries other than Yugoslavia and that the bill contemplated settlements of a similar nature in the future.

[32] Over the years Congress has frequently amended the International Claims Settlement Act to provide for particular problems arising out of settlement agreements, thus demonstrating Congress’ continuing acceptance of the President’s claim settlement authority. With respect to the Executive Agreement with the People’s Republic of China, for example, Congress established an allocation formula for distribution of the funds received pursuant to the Agreement. 22 U. S. C. § 1627 (f) (1976 ed., Supp. IV). As with legislation involving other executive agreements, Congress did not question the fact of the settlement or the power of the President to have concluded it. In 1976, Congress authorized the Foreign Claims Settlement Commission to adjudicate the merits of claims by United States nationals against East Germany, prior to any settlement with East Germany, so that the Executive would “be in a better position to negotiate an adequate settlement . . . of these claims.” S. Rep. No. 94-1188, p. 2 (1976); 22 U. S. C. § 1644b. Similarly, Congress recently amended the International Claims Settlement Act to facilitate the settlement of claims against Vietnam.

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[33] In addition to congressional acquiescence in the President’s power to settle claims, prior cases of this Court have also recognized that the President does have some measure of power to enter into executive agreements without obtaining the advice and consent of the Senate. In United States v. Pink, 315 U. S. 203 (1942), for example, the Court upheld the validity of the Litvinov Assignment, which was part of an Executive Agreement whereby the Soviet Union assigned to the United States amounts owed to it by American nationals so that outstanding claims of other American nationals could be paid. The Court explained that the resolution of such claims was integrally connected with normalizing United States’ relations with a foreign state:

[34] “Power to remove such obstacles to full recognition as settlement of claims of our nationals . . . certainly is a modest implied power of the President . . . . No such obstacle can be placed in the way of rehabilitation of relations between this country and another nation, unless the historic conception of the powers and responsibilities. . . is to be drastically revised.” Id., at 229-230.

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[35] Petitioner next asserts that Congress divested the President of the authority to settle claims when it enacted the Foreign Sovereign Immunities Act of 1976 (hereinafter FSIA). 28 U. S. C. §§ 1330, 1602 et seq. The FSIA granted personal and subject-matter jurisdiction in the federal district courts over commercial suits brought by claimants against those foreign states which have waived immunity. 28 U. S. C. § 1330.

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[36] Petitioner thus insists that the President, by suspending its claims, has circumscribed the jurisdiction of the United States courts in violation of Art. III of the Constitution.

[37] We disagree. In the first place, we do not believe that the President has attempted to divest the federal courts of jurisdiction. Executive Order No. 12294 purports only to “suspend” the claims, not divest the federal court of “jurisdiction.” As we read the Executive Order, those claims not within the jurisdiction of the Claims Tribunal will “revive” and become judicially enforceable in United States courts.

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[38] In light of all of the foregoing—the inferences to be drawn from the character of the legislation Congress has enacted in the area, such as the IEEPA and the Hostage Act, and from the history of acquiescence in executive claims settlement— we conclude that the President was authorized to suspend pending claims pursuant to Executive Order No. 12294. As Justice Frankfurter pointed out in Youngstown, 343 U. S., at 610-611, “a systematic, unbroken, executive practice, long pursued to the knowledge of the Congress and never before questioned . . . may be treated as a gloss on `Executive Power’ vested in the President by § 1 of Art. II.” Past practice does not, by itself, create power, but “long-continued practice, known to and acquiesced in by Congress, would raise a presumption that the [action] had been [taken] in pursuance of its consent . . . .” United States v. Midwest Oil Co., 236 U. S. 459, 474 (1915). See Haig v. Agee, ante, at 291-292. Such practice is present here and such a presumption is also appropriate. In light of the fact that Congress may be considered to have consented to the President’s action in suspending claims, we cannot say that action exceeded the President’s powers.

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[39] Just as importantly, Congress has not disapproved of the action taken here. Though Congress has held hearings on the Iranian Agreement itself, Congress has not enacted legislation, or even passed a resolution, indicating its displeasure with the Agreement. Quite the contrary, the relevant Senate Committee has stated that the establishment of the Tribunal is “of vital importance to the United States.” S. Rep. No. 97-71, p. 5 (1981). We are thus clearly not confronted with a situation in which Congress has in some way resisted the exercise of Presidential authority.

[40] Finally, we re-emphasize the narrowness of our decision. We do not decide that the President possesses plenary power to settle claims, even as against foreign governmental entities. As the Court of Appeals for the First Circuit stressed, “[t]he sheer magnitude of such a power, considered against the background of the diversity and complexity of modern international trade, cautions against any broader construction of authority than is necessary.” Chas. T. Main Int’l, Inc. v. Khuzestan Water & Power Authority, 651 F. 2d, at 814. But where, as here, the settlement of claims has been determined to be a necessary incident to the resolution of a major foreign policy dispute between our country and another, and where, as here, we can conclude that Congress acquiesced in the President’s action, we are not prepared to say that the President lacks the power to settle such claims.

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