Office of the Attorney General 

Washington, D.C. 

January 19, 2006 

The Honorable William H. Frist 

Majority Leader 

United States Senate 

Washington. D.C. 205 10 

Dear Mr. Leader: 

As the President recently described, in response to the attacks of Septcmber I I"', he has 

authorized the National Security Agency (NSA) to intcrcept international comn~unications into 

or out of the United States of persons linked to al Qaeda or an affiliated terrorist organization. 

The attached paper has becn prepared by the Department of Justice to provide a detailed analysis 

of the legal basis for those NSA activities dcscribcd by the President. 

As J have previously explained, these NSA activities al-e lawful in all respects. They 

represent a vital effort by the President to ensurc that we havc in place an early warning system 

to detect and prevent another catastrophic terrorist attack 011 America. In the o~lgoing armed 

conflict with al Qaeda and its allies, the President has the primary duty under the Constitution to 

protect the Anlerican people. The Constitution gives the President thc full authority necessary to 

carry out that solemn duty, and he has made clear that he will LIS~ allauthority available to him. 

consistent with the law, to protect the Nation. The President's authority to approve these NSA 

activities is confirmed and supplemented by Congress in the Authorization for Use of Military 

Force (AUMF), enacted on Septembcr 18, 2001. As discussed in depth in the attached paper, the 

President's use of his constitutional authority, as supplemented by statute in the AUMF, is 

consistent with the Foreign Intelligcnce Surveillance Act and is also fiilly protective of the civil 

liberties guaranteed by the Fourth Amendment. 

It is my hope that this paper will prove helpful to your understanding of the legal 

authorities underlying the NSA activities described by the President. 

Attorney General 

Enclosure 

cc: Thc Honorable Harry Reid 

Minority Lcader 
U.S. Department of Justice 

 Washington, D.C. 20530 

 January 19, 2006 

LEGAL AUTHORITIES SUPPORTING THE ACTIVITIES OF THE 

NATIONAL SECURITY AGENCY DESCRIBED BY THE PRESIDENT

As the President has explained, since shortly after the attacks of September 11, 2001, he 

has authorized the National Security Agency (“NSA”) to intercept international communications 

into and out of the United States of persons linked to al Qaeda or related terrorist organizations. 

The purpose of these intercepts is to establish an early warning system to detect and prevent 

another catastrophic terrorist attack on the United States. This paper addresses, in an 

unclassified form, the legal basis for the NSA activities described by the President (“NSA 

activities”). 

SUMMARY

On September 11, 2001, the al Qaeda terrorist network launched the deadliest foreign 

attack on American soil in history. Al Qaeda’s leadership repeatedly has pledged to attack the 

United States again at a time of its choosing, and these terrorist organizations continue to pose a 

grave threat to the United States. In response to the September 11th attacks and the continuing 

threat, the President, with broad congressional approval, has acted to protect the Nation from 

another terrorist attack. In the immediate aftermath of September 11th, the President promised 

that “[w]e will direct every resource at our command—every means of diplomacy, every tool of 

intelligence, every tool of law enforcement, every financial influence, and every weapon of 

war—to the destruction of and to the defeat of the global terrorist network.” President Bush 

Address to a Joint Session of Congress (Sept. 20, 2001). The NSA activities are an 

indispensable aspect of this defense of the Nation. By targeting the international 

communications into and out of the United States of persons reasonably believed to be linked to 

al Qaeda, these activities provide the United States with an early warning system to help avert 

the next attack. For the following reasons, the NSA activities are lawful and consistent with civil 

liberties. 

The NSA activities are supported by the President’s well-recognized inherent 

constitutional authority as Commander in Chief and sole organ for the Nation in foreign affairs 

to conduct warrantless surveillance of enemy forces for intelligence purposes to detect and 

disrupt armed attacks on the United States. The President has the chief responsibility under the 

Constitution to protect America from attack, and the Constitution gives the President the 

authority necessary to fulfill that solemn responsibility. The President has made clear that he 

will exercise all authority available to him, consistent with the Constitution, to protect the people 

of the United States. 
2

 

In the specific context of the current armed conflict with al Qaeda and related terrorist 

organizations, Congress by statute has confirmed and supplemented the President’s recognized 

authority under Article II of the Constitution to conduct such warrantless surveillance to prevent 

further catastrophic attacks on the homeland. In its first legislative response to the terrorist 

attacks of September 11th, Congress authorized the President to “use all necessary and 

appropriate force against those nations, organizations, or persons he determines planned, 

authorized, committed, or aided the terrorist attacks” of September 11th in order to prevent “any 

future acts of international terrorism against the United States.” Authorization for Use of 

Military Force, Pub. L. No. 107-40, § 2(a), 115 Stat. 224, 224 (Sept. 18, 2001) (reported as a 

note to 50 U.S.C.A. § 1541) (“AUMF”). History conclusively demonstrates that warrantless 

communications intelligence targeted at the enemy in time of armed conflict is a traditional and 

fundamental incident of the use of military force authorized by the AUMF. The Supreme 

Court’s interpretation of the AUMF in Hamdi v. Rumsfeld, 542 U.S. 507 (2004), confirms that 

Congress in the AUMF gave its express approval to the military conflict against al Qaeda and its 

allies and thereby to the President’s use of all traditional and accepted incidents of force in this 

current military conflict—including warrantless electronic surveillance to intercept enemy 

communications both at home and abroad. This understanding of the AUMF demonstrates 

Congress’s support for the President’s authority to protect the Nation and, at the same time, 

adheres to Justice O’Connor’s admonition that “a state of war is not a blank check for the 

President,” Hamdi, 542 U.S. at 536 (plurality opinion), particularly in view of the narrow scope 

of the NSA activities. 

The AUMF places the President at the zenith of his powers in authorizing the NSA 

activities. Under the tripartite framework set forth by Justice Jackson in Youngstown Sheet & 

Tube Co. v. Sawyer, 343 U.S. 579, 635-38 (1952) (Jackson, J., concurring), Presidential authority 

is analyzed to determine whether the President is acting in accordance with congressional 

authorization (category I), whether he acts in the absence of a grant or denial of authority by 

Congress (category II), or whether he uses his own authority under the Constitution to take 

actions incompatible with congressional measures (category III). Because of the broad 

authorization provided in the AUMF, the President’s action here falls within category I of Justice 

Jackson’s framework. Accordingly, the President’s power in authorizing the NSA activities is at 

its height because he acted “pursuant to an express or implied authorization of Congress,” and 

his power “includes all that he possesses in his own right plus all that Congress can delegate.” 

Id. at 635. 

The NSA activities are consistent with the preexisting statutory framework generally 

applicable to the interception of communications in the United States—the Foreign Intelligence 

Surveillance Act (“FISA”), as amended, 50 U.S.C. §§ 1801-1862 (2000 & Supp. II 2002), and 

relevant related provisions in chapter 119 of title 18.1

 Although FISA generally requires judicial 

approval of electronic surveillance, FISA also contemplates that Congress may authorize such 

surveillance by a statute other than FISA. See 50 U.S.C. § 1809(a) (prohibiting any person from 

intentionally “engag[ing] . . . in electronic surveillance under color of law except as authorized 

1

 Chapter 119 of title 18, which was enacted by Title III of the Omnibus Crime Control and Safe Streets 

Act of 1968, as amended, 18 U.S.C. §§ 2510-2521 (2000 & West Supp. 2005), is often referred to as “Title III.” 
3

by statute”). The AUMF, as construed by the Supreme Court in Hamdi and as confirmed by the 

history and tradition of armed conflict, is just such a statute. Accordingly, electronic 

surveillance conducted by the President pursuant to the AUMF, including the NSA activities, is 

fully consistent with FISA and falls within category I of Justice Jackson’s framework. 

Even if there were ambiguity about whether FISA, read together with the AUMF, permits 

the President to authorize the NSA activities, the canon of constitutional avoidance requires 

reading these statutes in harmony to overcome any restrictions in FISA and Title III, at least as 

they might otherwise apply to the congressionally authorized armed conflict with al Qaeda. 

Indeed, were FISA and Title III interpreted to impede the President’s ability to use the traditional 

tool of electronic surveillance to detect and prevent future attacks by a declared enemy that has 

already struck at the homeland and is engaged in ongoing operations against the United States, 

the constitutionality of FISA, as applied to that situation, would be called into very serious doubt. 

In fact, if this difficult constitutional question had to be addressed, FISA would be 

unconstitutional as applied to this narrow context. Importantly, the FISA Court of Review itself 

recognized just three years ago that the President retains constitutional authority to conduct 

foreign surveillance apart from the FISA framework, and the President is certainly entitled, at a 

minimum, to rely on that judicial interpretation of the Constitution and FISA. 

Finally, the NSA activities fully comply with the requirements of the Fourth Amendment. 

The interception of communications described by the President falls within a well-established 

exception to the warrant requirement and satisfies the Fourth Amendment’s fundamental 

requirement of reasonableness. The NSA activities are thus constitutionally permissible and 

fully protective of civil liberties. 

BACKGROUND

A. THE ATTACKS OF SEPTEMBER 11, 2001 

On September 11, 2001, the al Qaeda terrorist network launched a set of coordinated 

attacks along the East Coast of the United States. Four commercial jetliners, each carefully 

selected to be fully loaded with fuel for a transcontinental flight, were hijacked by al Qaeda 

operatives. Two of the jetliners were targeted at the Nation’s financial center in New York and 

were deliberately flown into the Twin Towers of the World Trade Center. The third was targeted 

at the headquarters of the Nation’s Armed Forces, the Pentagon. The fourth was apparently 

headed toward Washington, D.C., when passengers struggled with the hijackers and the plane 

crashed in Shanksville, Pennsylvania. The intended target of this fourth jetliner was evidently 

the White House or the Capitol, strongly suggesting that its intended mission was to strike a 

decapitation blow on the Government of the United States—to kill the President, the Vice 

President, or Members of Congress. The attacks of September 11th resulted in approximately 

3,000 deaths—the highest single-day death toll from hostile foreign attacks in the Nation’s 

history. These attacks shut down air travel in the United States, disrupted the Nation’s financial 

markets and government operations, and caused billions of dollars in damage to the economy. 
4

On September 14, 2001, the President declared a national emergency “by reason of the 

terrorist attacks at the World Trade Center, New York, New York, and the Pentagon, and the 

continuing and immediate threat of further attacks on the United States.” Proclamation No. 

7463, 66 Fed. Reg. 48,199 (Sept. 14, 2001). The same day, Congress passed a joint resolution 

authorizing the President “to use all necessary and appropriate force against those nations, 

organizations, or persons he determines planned, authorized, committed, or aided the terrorist 

attacks” of September 11th, which the President signed on September 18th. AUMF § 2(a). 

Congress also expressly acknowledged that the attacks rendered it “necessary and appropriate” 

for the United States to exercise its right “to protect United States citizens both at home and 

abroad,” and in particular recognized that “the President has authority under the Constitution to 

take action to deter and prevent acts of international terrorism against the United States.” Id. 

pmbl. Congress emphasized that the attacks “continue to pose an unusual and extraordinary 

threat to the national security and foreign policy of the United States.” Id. The United States 

also launched a large-scale military response, both at home and abroad. In the United States, 

combat air patrols were immediately established over major metropolitan areas and were 

maintained 24 hours a day until April 2002. The United States also immediately began plans for 

a military response directed at al Qaeda’s base of operations in Afghanistan. Acting under his 

constitutional authority as Commander in Chief, and with the support of Congress, the President 

dispatched forces to Afghanistan and, with the assistance of the Northern Alliance, toppled the 

Taliban regime. 

As the President made explicit in his Military Order of November 13, 2001, authorizing 

the use of military commissions to try terrorists, the attacks of September 11th “created a state of 

armed conflict.” Military Order § l(a), 66 Fed. Reg. 57,833 (Nov. 13, 2001). Indeed, shortly 

after the attacks, NATO—for the first time in its 46-year history—invoked article 5 of the North 

Atlantic Treaty, which provides that an “armed attack against one or more of [the parties] shall 

be considered an attack against them all.” North Atlantic Treaty, Apr. 4, 1949, art. 5, 63 Stat. 

2241, 2244, 34 U.N.T.S. 243, 246; see also Statement by NATO Secretary General Lord 

Robertson (Oct. 2, 2001), available at http://www.nato.int/docu/speech/2001/s011002a.htm 

(“[I]t has now been determined that the attack against the United States on 11 September was 

directed from abroad and shall therefore be regarded as an action covered by Article 5 of the 

Washington Treaty . . . .”). The President also determined in his Military Order that al Qaeda 

and related terrorists organizations “possess both the capability and the intention to undertake 

further terrorist attacks against the United States that, if not detected and prevented, will cause 

mass deaths, mass injuries, and massive destruction of property, and may place at risk the 

continuity of the operations of the United States Government,” and concluded that “an 

extraordinary emergency exists for national defense purposes.” Military Order, § l(c), (g), 66 

Fed. Reg. at 57,833-34. 

B. THE NSA ACTIVITIES

Against this unfolding background of events in the fall of 2001, there was substantial 

concern that al Qaeda and its allies were preparing to carry out another attack within the United 

States. Al Qaeda had demonstrated its ability to introduce agents into the United States 

undetected and to perpetrate devastating attacks, and it was suspected that additional agents were 
5

likely already in position within the Nation’s borders. As the President has explained, unlike a 

conventional enemy, al Qaeda has infiltrated “our cities and communities and communicated 

from here in America to plot and plan with bin Laden’s lieutenants in Afghanistan, Pakistan and 

elsewhere.” Press Conference of President Bush (Dec. 19, 2005), available at http://www.whitehouse.gov/news/releases/2005/12/20051219-2.html (“President’s Press Conference”). To this 

day, finding al Qaeda sleeper agents in the United States remains one of the paramount concerns 

in the War on Terror. As the President has explained, “[t]he terrorists want to strike America 

again, and they hope to inflict even more damage than they did on September the 11th.” Id. 

The President has acknowledged that, to counter this threat, he has authorized the NSA to 

intercept international communications into and out of the United States of persons linked to al 

Qaeda or related terrorist organizations. The same day, the Attorney General elaborated and 

explained that in order to intercept a communication, there must be “a reasonable basis to 

conclude that one party to the communication is a member of al Qaeda, affiliated with al Qaeda, 

or a member of an organization affiliated with al Qaeda.” Press Briefing by Attorney General 

Alberto Gonzales and General Michael Hayden, Principal Deputy Director for National 

Intelligence, available at http://www.whitehouse.gov/news/releases/2005/12/20051219-1.html 

(Dec. 19, 2005) (statement of Attorney General Gonzales). The purpose of these intercepts is to 

establish an early warning system to detect and prevent another catastrophic terrorist attack on 

the United States. The President has stated that the NSA activities “ha[ve] been effective in 

disrupting the enemy, while safeguarding our civil liberties.” President’s Press Conference. 

The President has explained that the NSA activities are “critical” to the national security 

of the United States. Id. Confronting al Qaeda “is not simply a matter of [domestic] law 

enforcement”—we must defend the country against an enemy that declared war against the 

United States. Id. To “effectively detect enemies hiding in our midst and prevent them from 

striking us again . . . we must be able to act fast and to detect conversations [made by individuals 

linked to al Qaeda] so we can prevent new attacks.” Id. The President pointed out that “a twominute phone conversation between somebody linked to al Qaeda here and an operative overseas 

could lead directly to the loss of thousands of lives.” Id. The NSA activities are intended to help 

“connect the dots” between potential terrorists. Id. In addition, the Nation is facing “a different 

era, a different war . . . people are changing phone numbers . . . and they’re moving quick[ly].” 

Id. As the President explained, the NSA activities “enable[] us to move faster and quicker. And 

that’s important. We’ve got to be fast on our feet, quick to detect and prevent.” Id. “This is an 

enemy that is quick and it’s lethal. And sometimes we have to move very, very quickly.” Id. 

FISA, by contrast, is better suited “for long-term monitoring.” Id. 

As the President has explained, the NSA activities are “carefully reviewed approximately 

every 45 days to ensure that [they are] being used properly.” Id. These activities are reviewed 

for legality by the Department of Justice and are monitored by the General Counsel and 

Inspector General of the NSA to ensure that civil liberties are being protected. Id. Leaders in 

Congress from both parties have been briefed more than a dozen times on the NSA activities. 
6

C. THE CONTINUING THREAT POSED BY AL QAEDA 

Before the September 11th attacks, al Qaeda had promised to attack the United States. In 

1998, Osama bin Laden declared a “religious” war against the United States and urged that it 

was the moral obligation of all Muslims to kill U.S. civilians and military personnel. See 

Statement of Osama bin Laden, Ayman al-Zawahiri, et al., Fatwah Urging Jihad Against 

Americans, published in Al-Quds al-’Arabi (Feb. 23, 1998) (“To kill the Americans and their 

allies—civilians and military—is an individual duty for every Muslim who can do it in any 

country in which it is possible to do it, in order to liberate the al-Aqsa Mosque and the holy 

mosque from their grip, and in order for their armies to move out of all the lands of Islam, 

defeated and unable to threaten any Muslim.”). Al Qaeda carried out those threats with a 

vengeance; they attacked the U.S.S. Cole in Yemen, the United States Embassy in Nairobi, and 

finally the United States itself in the September 11th attacks. 

It is clear that al Qaeda is not content with the damage it wrought on September 11th. As 

recently as December 7, 2005, Ayman al-Zawahiri professed that al Qaeda “is spreading, 

growing, and becoming stronger,” and that al Qaeda is “waging a great historic battle in Iraq, 

Afghanistan, Palestine, and even in the Crusaders’ own homes.” Ayman al-Zawahiri, videotape 

released on Al-Jazeera television network (Dec. 7, 2005). Indeed, since September 11th, al 

Qaeda leaders have repeatedly promised to deliver another, even more devastating attack on 

America. See, e.g., Osama bin Laden, videotape released on Al-Jazeera television network (Oct. 

24, 2004) (warning United States citizens of further attacks and asserting that “your security is in 

your own hands”); Osama bin Laden, videotape released on Al-Jazeera television network (Oct. 

18, 2003) (“We, God willing, will continue to fight you and will continue martyrdom operations 

inside and outside the United States . . . .”); Ayman Al-Zawahiri, videotape released on the AlJazeera television network (Oct. 9, 2002) (“I promise you [addressing the ‘citizens of the United 

States’] that the Islamic youth are preparing for you what will fill your hearts with horror”). 

Given that al Qaeda’s leaders have repeatedly made good on their threats and that al Qaeda has 

demonstrated its ability to insert foreign agents into the United States to execute attacks, it is 

clear that the threat continues. Indeed, since September 11th, al Qaeda has staged several largescale attacks around the world, including in Indonesia, Madrid, and London, killing hundreds of 

innocent people. 

ANALYSIS

I. THE PRESIDENT HAS INHERENT CONSTITUTIONAL AUTHORITY TO ORDER 

WARRANTLESS FOREIGN INTELLIGENCE SURVEILLANCE

As Congress expressly recognized in the AUMF, “the President has authority under the 

Constitution to take action to deter and prevent acts of international terrorism against the United 

States,” AUMF pmbl., especially in the context of the current conflict. Article II of the 

Constitution vests in the President all executive power of the United States, including the power 

to act as Commander in Chief of the Armed Forces, see U.S. Const. art. II, § 2, and authority 

over the conduct of the Nation’s foreign affairs. As the Supreme Court has explained, “[t]he 

President is the sole organ of the nation in its external relations, and its sole representative with 
7

foreign nations.” United States v. Curtiss-Wright Export Corp., 299 U.S. 304, 319 (1936) 

(internal quotation marks and citations omitted). In this way, the Constitution grants the 

President inherent power to protect the Nation from foreign attack, see, e.g., The Prize Cases, 67 

U.S. (2 Black) 635, 668 (1863), and to protect national security information, see, e.g., 

Department of the Navy v. Egan, 484 U.S. 518, 527 (1988). 

To carry out these responsibilities, the President must have authority to gather 

information necessary for the execution of his office. The Founders, after all, intended the 

federal Government to be clothed with all authority necessary to protect the Nation. See, e.g., 

The Federalist No. 23, at 147 (Alexander Hamilton) (Jacob E. Cooke ed. 1961) (explaining that 

the federal Government will be “cloathed with all the powers requisite to the complete execution 

of its trust”); id. No. 41, at 269 (James Madison) (“Security against foreign danger is one of the 

primitive objects of civil society . . . . The powers requisite for attaining it must be effectually 

confided to the federal councils.”). Because of the structural advantages of the Executive 

Branch, the Founders also intended that the President would have the primary responsibility and 

necessary authority as Commander in Chief and Chief Executive to protect the Nation and to 

conduct the Nation’s foreign affairs. See, e.g., The Federalist No. 70, at 471-72 (Alexander 

Hamilton); see also Johnson v. Eisentrager, 339 U.S. 763, 788 (1950) (“this [constitutional] 

grant of war power includes all that is necessary and proper for carrying these powers into 

execution”) (citation omitted). Thus, it has been long recognized that the President has the 

authority to use secretive means to collect intelligence necessary for the conduct of foreign 

affairs and military campaigns. See, e.g., Chicago & S. Air Lines v. Waterman S.S. Corp., 333 

U.S. 103, 111 (1948) (“The President, both as Commander-in-Chief and as the Nation’s organ 

for foreign affairs, has available intelligence services whose reports are not and ought not to be 

published to the world.”); Curtiss-Wright, 299 U.S. at 320 (“He has his confidential sources of 

information. He has his agents in the form of diplomatic, consular and other officials.”); Totten 

v. United States, 92 U.S. 105, 106 (1876) (President “was undoubtedly authorized during the 

war, as commander-in-chief . . . to employ secret agents to enter the rebel lines and obtain 

information respecting the strength, resources, and movements of the enemy”). 

In reliance on these principles, a consistent understanding has developed that the 

President has inherent constitutional authority to conduct warrantless searches and surveillance 

within the United States for foreign intelligence purposes. Wiretaps for such purposes thus have 

been authorized by Presidents at least since the administration of Franklin Roosevelt in 1940. 

See, e.g., United States v. United States District Court, 444 F.2d 651, 669-71 (6th Cir. 1971) 

(reproducing as an appendix memoranda from Presidents Roosevelt, Truman, and Johnson). In a 

Memorandum to Attorney General Jackson, President Roosevelt wrote on May 21, 1940: 

You are, therefore, authorized and directed in such cases as you may approve, 

after investigation of the need in each case, to authorize the necessary 

investigation agents that they are at liberty to secure information by listening 

devices directed to the conversation or other communications of persons 

suspected of subversive activities against the Government of the United States, 

including suspected spies. You are requested furthermore to limit these 

investigations so conducted to a minimum and limit them insofar as 
8

possible to aliens. 

Id. at 670 (appendix A). President Truman approved a memorandum drafted by Attorney 

General Tom Clark in which the Attorney General advised that “it is as necessary as it was in 

1940 to take the investigative measures” authorized by President Roosevelt to conduct electronic 

surveillance “in cases vitally affecting the domestic security.” Id. Indeed, while FISA was being 

debated during the Carter Administration, Attorney General Griffin Bell testified that “the 

current bill recognizes no inherent power of the President to conduct electronic surveillance, and 

I want to interpolate here to say that this does not take away the power [of] the President under 

the Constitution.” Foreign Intelligence Electronic Surveillance Act of 1978: Hearings on H.R. 

5764, H.R. 9745, H.R. 7308, and H.R. 5632 Before the Subcomm. on Legislation of the House 

Comm. on Intelligence, 95th Cong., 2d Sess. 15 (1978) (emphasis added); see also Katz v. 

United States, 389 U.S. 347, 363 (1967) (White, J., concurring) (“Wiretapping to protect the 

security of the Nation has been authorized by successive Presidents.”); cf. Amending the Foreign 

Intelligence Surveillance Act: Hearings Before the House Permanent Select Comm. on 

Intelligence,103d Cong. 2d Sess. 61 (1994) (statement of Deputy Attorney General Jamie S. 

Gorelick) (“[T]he Department of Justice believes, and the case law supports, that the President 

has inherent authority to conduct warrantless physical searches for foreign intelligence 

purposes . . . .”). 

The courts uniformly have approved this longstanding Executive Branch practice. 

Indeed, every federal appellate court to rule on the question has concluded that, even in 

peacetime, the President has inherent constitutional authority, consistent with the Fourth 

Amendment, to conduct searches for foreign intelligence purposes without securing a judicial 

warrant. See In re Sealed Case, 310 F.3d 717, 742 (Foreign Intel. Surv. Ct. of Rev. 2002) (“[A]ll 

the other courts to have decided the issue [have] held that the President did have inherent 

authority to conduct warrantless searches to obtain foreign intelligence information . . . . We take 

for granted that the President does have that authority and, assuming that is so, FISA could not 

encroach on the President’s constitutional power.”) (emphasis added); accord, e.g., United 

States v. Truong Dinh Hung, 629 F.2d 908 (4th Cir. 1980); United States v. Butenko, 494 F.2d 

593 (3d Cir. 1974) (en banc); United States v. Brown, 484 F.2d 418 (5th Cir. 1973). But cf. 

Zweibon v. Mitchell, 516 F.2d 594 (D.C. Cir. 1975) (en banc) (dictum in plurality opinion 

suggesting that a warrant would be required even in a foreign intelligence investigation). 

In United States v. United States District Court, 407 U.S. 297 (1972) (the “Keith” case), 

the Supreme Court concluded that the Fourth Amendment’s warrant requirement applies to 

investigations of wholly domestic threats to security—such as domestic political violence and 

other crimes. But the Court in the Keith case made clear that it was not addressing the 

President’s authority to conduct foreign intelligence surveillance without a warrant and that it 

was expressly reserving that question: “[T]he instant case requires no judgment on the scope of 

the President’s surveillance power with respect to the activities of foreign powers, within or 

without this country.” Id. at 308; see also id. at 321-22 & n.20 (“We have not addressed, and 

express no opinion as to, the issues which may be involved with respect to activities of foreign 

powers or their agents.”). That Keith does not apply in the context of protecting against a foreign 

attack has been confirmed by the lower courts. After Keith, each of the three courts of appeals 
9

 

that have squarely considered the question have concluded—expressly taking the Supreme 

Court’s decision into account—that the President has inherent authority to conduct warrantless 

surveillance in the foreign intelligence context. See, e.g., Truong Dinh Hung, 629 F.2d at 913-

14; Butenko, 494 F.2d at 603; Brown, 484 F.2d 425-26. 

From a constitutional standpoint, foreign intelligence surveillance such as the NSA 

activities differs fundamentally from the domestic security surveillance at issue in Keith. As the 

Fourth Circuit observed, the President has uniquely strong constitutional powers in matters 

pertaining to foreign affairs and national security. “Perhaps most crucially, the executive branch 

not only has superior expertise in the area of foreign intelligence, it is also constitutionally 

designated as the pre-eminent authority in foreign affairs.” Truong, 629 F.2d at 914; see id. at 

913 (noting that “the needs of the executive are so compelling in the area of foreign intelligence, 

unlike the area of domestic security, that a uniform warrant requirement would . . . unduly 

frustrate the President in carrying out his foreign affairs responsibilities”); cf. Haig v. Agee, 453 

U.S. 280, 292 (1981) (“Matters intimately related to foreign policy and national security are 

rarely proper subjects for judicial intervention.”).2

The present circumstances that support recognition of the President’s inherent 

constitutional authority to conduct the NSA activities are considerably stronger than were the 

circumstances at issue in the earlier courts of appeals cases that recognized this power. All of the 

cases described above addressed inherent executive authority under the foreign affairs power to 

conduct surveillance in a peacetime context. The courts in these cases therefore had no occasion 

even to consider the fundamental authority of the President, as Commander in Chief, to gather 

intelligence in the context of an ongoing armed conflict in which the United States already had 

suffered massive civilian casualties and in which the intelligence gathering efforts at issue were 

specifically designed to thwart further armed attacks. Indeed, intelligence gathering is 

particularly important in the current conflict, in which the enemy attacks largely through 

clandestine activities and which, as Congress recognized, “pose[s] an unusual and extraordinary 

threat,” AUMF pmbl. 

Among the President’s most basic constitutional duties is the duty to protect the Nation 

from armed attack. The Constitution gives him all necessary authority to fulfill that 

responsibility. The courts thus have long acknowledged the President’s inherent authority to 

take action to protect Americans abroad, see, e.g., Durand v. Hollins, 8 F. Cas. 111, 112 

(C.C.S.D.N.Y. 1860) (No. 4186), and to protect the Nation from attack, see, e.g., The Prize 

Cases, 67 U.S. at 668. See generally Ex parte Quirin, 317 U.S. 1, 28 (1942) (recognizing that 

2

 Keith made clear that one of the significant concerns driving the Court’s conclusion in the domestic 

security context was the inevitable connection between perceived threats to domestic security and political dissent. 

As the Court explained: “Fourth Amendment protections become the more necessary when the targets of official 

surveillance may be those suspected of unorthodoxy in their political beliefs. The danger to political dissent is acute 

where the Government attempts to act under so vague a concept as the power to protect ‘domestic security.’” Keith, 

407 U.S. at 314; see also id. at 320 (“Security surveillances are especially sensitive because of the inherent 

vagueness of the domestic security concept, the necessarily broad and continuing nature of intelligence gathering, 

and the temptation to utilize such surveillances to oversee political dissent.”). Surveillance of domestic groups 

raises a First Amendment concern that generally is not present when the subjects of the surveillance are foreign 

powers or their agents. 
10

 

the President has authority under the Constitution “to direct the performance of those functions 

which may constitutionally be performed by the military arm of the nation in time of war,” 

including “important incident[s] to the conduct of war,” such as “the adoption of measures by the 

military command . . . to repel and defeat the enemy”). As the Supreme Court emphasized in the 

Prize Cases, if the Nation is invaded, the President is “bound to resist force by force”; “[h]e must 

determine what degree of force the crisis demands” and need not await congressional sanction to 

do so. The Prize Cases, 67 U.S. at 670; see also Campbell v. Clinton, 203 F.3d 19, 27 (D.C. Cir. 

2000) (Silberman, J., concurring) (“[T]he Prize Cases . . . stand for the proposition that the 

President has independent authority to repel aggressive acts by third parties even without specific 

congressional authorization, and courts may not review the level of force selected.”); id. at 40 

(Tatel, J., concurring) (“[T]he President, as commander in chief, possesses emergency authority 

to use military force to defend the nation from attack without obtaining prior congressional 

approval.”). Indeed, “in virtue of his rank as head of the forces, [the President] has certain 

powers and duties with which Congress cannot interfere.” Training of British Flying Students in 

the United States, 40 Op. Att’y Gen. 58, 61 (1941) (Attorney General Robert H. Jackson) 

(internal quotation marks omitted). In exercising his constitutional powers, the President has 

wide discretion, consistent with the Constitution, over the methods of gathering intelligence 

about the Nation’s enemies in a time of armed conflict. 

II. THE AUMF CONFIRMS AND SUPPLEMENTS THE PRESIDENT’S INHERENT POWER TO 

USE WARRANTLESS SURVEILLANCE AGAINST THE ENEMY IN THE CURRENT ARMED 

CONFLICT

In the Authorization for Use of Military Force enacted in the wake of September 11th, 

Congress confirms and supplements the President’s constitutional authority to protect the Nation, 

including through electronic surveillance, in the context of the current post-September 11th 

armed conflict with al Qaeda and its allies. The broad language of the AUMF affords the 

President, at a minimum, discretion to employ the traditional incidents of the use of military 

force. The history of the President’s use of warrantless surveillance during armed conflicts 

demonstrates that the NSA surveillance described by the President is a fundamental incident of 

the use of military force that is necessarily included in the AUMF. 

A. THE TEXT AND PURPOSE OF THE AUMF AUTHORIZE THE NSA ACTIVITIES 

On September 14, 2001, in its first legislative response to the attacks of September 11th, 

Congress gave its express approval to the President’s military campaign against al Qaeda and, in 

the process, confirmed the well-accepted understanding of the President’s Article II powers. See 

AUMF § 2(a).3

 In the preamble to the AUMF, Congress stated that “the President has authority 

under the Constitution to take action to deter and prevent acts of international terrorism against 

the United States,” AUMF pmbl., and thereby acknowledged the President’s inherent 

constitutional authority to defend the United States. This clause “constitutes an extraordinarily 

3

 America’s military response began before the attacks of September 11th had been completed. See The 

9/11 Commission Report 20 (2004). Combat air patrols were established and authorized “to engage inbound aircraft 

if they could verify that the aircraft was hijacked.” Id. at 42. 
11

sweeping recognition of independent presidential constitutional power to employ the war power 

to combat terrorism.” Michael Stokes Paulsen, Youngstown Goes to War, 19 Const. Comment. 

215, 252 (2002). This striking recognition of presidential authority cannot be discounted as the 

product of excitement in the immediate aftermath of September 11th, for the same terms were 

repeated by Congress more than a year later in the Authorization for Use of Military Force 

Against Iraq Resolution of 2002. Pub. L. No. 107-243, pmbl., 116 Stat. 1498, 1500 (Oct. 16, 

2002) (“[T]he President has authority under the Constitution to take action in order to deter and 

prevent acts of international terrorism against the United States . . . .”). In the context of the 

conflict with al Qaeda and related terrorist organizations, therefore, Congress has acknowledged 

a broad executive authority to “deter and prevent” further attacks against the United States. 

The AUMF passed by Congress on September 14, 2001, does not lend itself to a narrow 

reading. Its expansive language authorizes the President “to use all necessary and appropriate 

force against those nations, organizations, or persons he determines planned, authorized, 

committed, or aided the terrorist attacks that occurred on September 11, 2001.” AUMF § 2(a) 

(emphases added). In the field of foreign affairs, and particularly that of war powers and 

national security, congressional enactments are to be broadly construed where they indicate 

support for authority long asserted and exercised by the Executive Branch. See, e.g., Haig v. 

Agee, 453 U.S. 280, 293-303 (1981); United States ex rel. Knauff v. Shaughnessy, 338 U.S. 537, 

543-45 (1950); cf. Loving v. United States, 517 U.S. 748, 772 (1996) (noting that the usual 

“limitations on delegation [of congressional powers] do not apply” to authorizations linked to the 

Commander in Chief power); Dames & Moore v. Regan, 453 U.S. 654, 678-82 (1981) (even 

where there is no express statutory authorization for executive action, legislation in related field 

may be construed to indicate congressional acquiescence in that action). Although Congress’s 

war powers under Article I, Section 8 of the Constitution empower Congress to legislate 

regarding the raising, regulation, and material support of the Armed Forces and related matters, 

rather than the prosecution of military campaigns, the AUMF indicates Congress’s endorsement 

of the President’s use of his constitutional war powers. This authorization transforms the 

struggle against al Qaeda and related terrorist organizations from what Justice Jackson called “a 

zone of twilight,” in which the President and the Congress may have concurrent powers whose 

“distribution is uncertain,” Youngstown Sheet & Tube Co. v. Sawyer, 343 U.S. 579, 637 (1952) 

(Jackson, J., concurring), into a situation in which the President’s authority is at is maximum 

because “it includes all that he possesses in his own right plus all that Congress can delegate,” id. 

at 635. With regard to these fundamental tools of warfare—and, as demonstrated below, 

warrantless electronic surveillance against the declared enemy is one such tool—the AUMF 

places the President’s authority at its zenith under Youngstown. 

It is also clear that the AUMF confirms and supports the President’s use of those 

traditional incidents of military force against the enemy, wherever they may be—on United 

States soil or abroad. The nature of the September 11th attacks—launched on United States soil 

by foreign agents secreted in the United States—necessitates such authority, and the text of the 

AUMF confirms it. The operative terms of the AUMF state that the President is authorized to 

use force “in order to prevent any future acts of international terrorism against the United 

States,” id., an objective which, given the recent attacks within the Nation’s borders and the 

continuing use of air defense throughout the country at the time Congress acted, undoubtedly 
12

contemplated the possibility of military action within the United States. The preamble, 

moreover, recites that the United States should exercise its rights “to protect United States 

citizens both at home and abroad.” Id. pmbl. (emphasis added). To take action against those 

linked to the September 11th attacks involves taking action against individuals within the United 

States. The United States had been attacked on its own soil—not by aircraft launched from 

carriers several hundred miles away, but by enemy agents who had resided in the United States 

for months. A crucial responsibility of the President—charged by the AUMF and the 

Constitution—was and is to identify and attack those enemies, especially if they were in the 

United States, ready to strike against the Nation. 

The text of the AUMF demonstrates in an additional way that Congress authorized the 

President to conduct warrantless electronic surveillance against the enemy. The terms of the 

AUMF not only authorized the President to “use all necessary and appropriate force” against 

those responsible for the September 11th attacks; it also authorized the President to 

“determine[]” the persons or groups responsible for those attacks and to take all actions 

necessary to prevent further attacks. AUMF § 2(a) (“the President is authorized to use all 

necessary and appropriate force against those nations, organizations, or persons he determines

planned, authorized, committed, or aided the terrorist attacks that occurred on September 11th, 

2001, or harbored such organizations or persons”) (emphasis added). Of vital importance to the 

use of force against the enemy is locating the enemy and identifying its plans of attack. And of 

vital importance to identifying the enemy and detecting possible future plots was the authority to 

intercept communications to or from the United States of persons with links to al Qaeda or 

related terrorist organizations. Given that the agents who carried out the initial attacks resided in 

the United States and had successfully blended into American society and disguised their 

identities and intentions until they were ready to strike, the necessity of using the most effective 

intelligence gathering tools against such an enemy, including electronic surveillance, was patent. 

Indeed, Congress recognized that the enemy in this conflict poses an “unusual and extraordinary 

threat.” AUMF pmbl. 

The Supreme Court’s interpretation of the scope of the AUMF in Hamdi v. Rumsfeld, 542 

U.S. 507 (2004), strongly supports this reading of the AUMF. In Hamdi, five members of the 

Court found that the AUMF authorized the detention of an American within the United States, 

notwithstanding a statute that prohibits the detention of U.S. citizens “except pursuant to an Act 

of Congress,” 18 U.S.C. § 4001(a). See Hamdi, 542 U.S. at 519 (plurality opinion); id. at 587 

(Thomas, J., dissenting). Drawing on historical materials and “longstanding law-of-war 

principles,” id. at 518-21, a plurality of the Court concluded that detention of combatants who 

fought against the United States as part of an organization “known to have supported” al Qaeda 

“is so fundamental and accepted an incident to war as to be an exercise of the ‘necessary and 

appropriate force’ Congress has authorized the President to use.” Id. at 518; see also id. at 587 

(Thomas, J., dissenting) (agreeing with the plurality that the joint resolution authorized the 

President to “detain those arrayed against our troops”); accord Quirin, 317 U.S. at 26-29, 38 

(recognizing the President’s authority to capture and try agents of the enemy in the United States 

even if they had never “entered the theatre or zone of active military operations”). Thus, even 

though the AUMF does not say anything expressly about detention, the Court nevertheless found 

that it satisfied section 4001(a)’s requirement that detention be congressionally authorized.
13

 

The conclusion of five Justices in Hamdi that the AUMF incorporates fundamental 

“incidents” of the use of military force makes clear that the absence of any specific reference to 

signals intelligence activities in the resolution is immaterial. See Hamdi, 542 U.S. at 519 (“[I]t is 

of no moment that the AUMF does not use specific language of detention.”) (plurality opinion). 

Indeed, given the circumstances in which the AUMF was adopted, it is hardly surprising that 

Congress chose to speak about the President’s authority in general terms. The purpose of the 

AUMF was for Congress to sanction and support the military response to the devastating terrorist 

attacks that had occurred just three days earlier. Congress evidently thought it neither necessary 

nor appropriate to attempt to catalog every specific aspect of the use of the forces it was 

authorizing and every potential preexisting statutory limitation on the Executive Branch. Rather 

than engage in that difficult and impractical exercise, Congress authorized the President, in 

general but intentionally broad terms, to use the traditional and fundamental incidents of war and 

to determine how best to identify and engage the enemy in the current armed conflict. 

Congress’s judgment to proceed in this manner was unassailable, for, as the Supreme Court has 

recognized, even in normal times involving no major national security crisis, “Congress cannot 

anticipate and legislate with regard to every possible action the President may find it necessary to 

take.” Dames & Moore, 453 U.S. at 678. Indeed, Congress often has enacted authorizations to 

use military force using general authorizing language that does not purport to catalogue in detail 

the specific powers the President may employ. The need for Congress to speak broadly in 

recognizing and augmenting the President’s core constitutional powers over foreign affairs and 

military campaigns is of course significantly heightened in times of national emergency. See 

Zemel v. Rusk, 381 U.S. 1, 17 (1965) (“[B]ecause of the changeable and explosive nature of 

contemporary international relations . . . Congress—in giving the Executive authority over 

matters of foreign affairs—must of necessity paint with a brush broader than that it customarily 

wields in domestic areas.”). 

Hamdi thus establishes the proposition that the AUMF “clearly and unmistakably” 

authorizes the President to take actions against al Qaeda and related organizations that amount to 

“fundamental incident[s] of waging war.” Hamdi, 542 U.S. at 519 (plurality opinion); see also 

id. at 587 (Thomas, J., dissenting). In other words, “[t]he clear inference is that the AUMF 

authorizes what the laws of war permit.” Curtis A. Bradley & Jack L. Goldsmith, Congressional 

Authorization and the War on Terrorism, 118 Harv. L. Rev. 2048, 2092 (2005) (emphasis 

added). Congress is presumed to be aware of the Supreme Court’s precedents. Indeed, Congress 

recently enacted legislation in response to the Court’s decision in Rasul v. Bush, 542 U.S. 466 

(2004)—which was issued the same day as the Hamdi decision—removing habeas corpus 

jurisdiction over claims filed on behalf of confined enemy combatants held at Guantanamo Bay. 

Congress, however, has not expressed any disapproval of the Supreme Court’s commonsense 

and plain-meaning interpretation of the AUMF in Hamdi.

4

4

 This understanding of the AUMF is consistent with Justice O’Connor’s admonition that “a state of war is 

not a blank check for the President,” Hamdi, 542 U.S. at 536 (plurality opinion). In addition to constituting a 

fundamental and accepted incident of the use of military force, the NSA activities are consistent with the law of 

armed conflict principle that the use of force be necessary and proportional. See Dieter Fleck, The Handbook of 

Humanitarian Law in Armed Conflicts 115 (1995). The NSA activities are proportional because they are minimally 

invasive and narrow in scope, targeting only the international communications of persons reasonably believed to be 

linked to al Qaeda, and are designed to protect the Nation from a devastating attack. 
14

B. WARRANTLESS ELECTRONIC SURVEILLANCE AIMED AT INTERCEPTING ENEMY 

COMMUNICATIONS HAS LONG BEEN RECOGNIZED AS A FUNDAMENTAL 

INCIDENT OF THE USE OF MILITARY FORCE 

The history of warfare—including the consistent practice of Presidents since the earliest 

days of the Republic—demonstrates that warrantless intelligence surveillance against the enemy 

is a fundamental incident of the use of military force, and this history confirms the statutory 

authority provided by the AUMF. Electronic surveillance is a fundamental tool of war that must 

be included in any natural reading of the AUMF’s authorization to use “all necessary and 

appropriate force.” 

As one author has explained: 

It is essential in warfare for a belligerent to be as fully informed as possible about 

the enemy—his strength, his weaknesses, measures taken by him and measures 

contemplated by him. This applies not only to military matters, but . . . anything 

which bears on and is material to his ability to wage the war in which he is 

engaged. The laws of war recognize and sanction this aspect of warfare. 

Morris Greenspan, The Modern Law of Land Warfare 325 (1959) (emphases added); see also 

Memorandum for Members of the House Permanent Select Comm. on Intel., from Jeffrey H. 

Smith, Re: Legal Authorities Regarding Warrantless Surveillance of U.S. Persons 6 (Jan. 3, 

2006) (“Certainly, the collection of intelligence is understood to be necessary to the execution of 

the war.”). Similarly, article 24 of the Hague Regulations of 1907 expressly states that “the 

employment of measures necessary for obtaining information about the enemy and the country 

[is] considered permissible.” See also L. Oppenheim, International Law vol. II § 159 (7th ed. 

1952) (“War cannot be waged without all kinds of information, about the forces and the 

intentions of the enemy . . . . To obtain the necessary information, it has always been considered 

lawful to employ spies . . . .”); Joseph R. Baker & Henry G. Crocker, The Laws of Land Warfare 

197 (1919) (“Every belligerent has a right . . . to discover the signals of the enemy and . . . to 

seek to procure information regarding the enemy through the aid of secret agents.”); cf. J.M. 

Spaight, War Rights on Land 205 (1911) (“[E]very nation employs spies; were a nation so 

quixotic as to refrain from doing so, it might as well sheathe its sword for ever. . . . Spies . . . are 

indispensably necessary to a general; and, other things being equal, that commander will be 

victorious who has the best secret service.”) (internal quotation marks omitted). 

In accordance with these well-established principles, the Supreme Court has consistently 

recognized the President’s authority to conduct intelligence activities. See, e.g., Totten v. United 

States, 92 U.S. 105, 106 (1876) (recognizing President’s authority to hire spies); Tenet v. Doe, 

544 U.S. 1 (2005) (reaffirming Totten and counseling against judicial interference with such 

matters); see also Chicago & S. Air Lines v. Waterman S.S. Corp., 333 U.S. 103, 111 (1948) 

(“The President, both as Commander-in-Chief and as the Nation’s organ for foreign affairs, has 

available intelligence services whose reports neither are not and ought not to be published to the 

world.”); United States v. Curtiss-Wright Export Corp., 299 U.S. 304, 320 (1936) (The President 

“has his confidential sources of information. He has his agents in the form of diplomatic, 
15

consular, and other officials.”). Chief Justice John Marshall even described the gathering of 

intelligence as a military duty. See Tatum v. Laird, 444 F.2d 947, 952-53 (D.C. Cir. 1971) (“As 

Chief Justice John Marshall said of Washington, ‘A general must be governed by his intelligence 

and must regulate his measures by his information. It is his duty to obtain correct 

information . . . . ’”) (quoting Foreword, U.S. Army Basic Field Manual, Vol. X, circa 1938), 

rev’d on other grounds, 408 U.S. 1 (1972). 

The United States, furthermore, has a long history of wartime surveillance—a history that 

can be traced to George Washington, who “was a master of military espionage” and “made 

frequent and effective use of secret intelligence in the second half of the eighteenth century.” 

Rhodri Jeffreys-Jones, Cloak and Dollar: A History of American Secret Intelligence 11 (2002); 

see generally id. at 11-23 (recounting Washington’s use of intelligence); see also Haig v. Agee, 

471 U.S. 159, 172 n.16 (1981) (quoting General Washington’s letter to an agent embarking upon 

an intelligence mission in 1777: “The necessity of procuring good intelligence, is apparent and 

need not be further urged.”). As President in 1790, Washington obtained from Congress a 

“secret fund” to deal with foreign dangers and to be spent at his discretion. Jeffreys-Jones, 

supra, at 22. The fund, which remained in use until the creation of the Central Intelligence 

Agency in the mid-twentieth century and gained “longstanding acceptance within our 

constitutional structure,” Halperin v. CIA, 629 F.2d 144, 158-59 (D.C. Cir. 1980), was used “for 

all purposes to which a secret service fund should or could be applied for the public benefit,” 

including “for persons sent publicly and secretly to search for important information, political or 

commercial,” id. at 159 (quoting Statement of Senator John Forsyth, Cong. Debates 295 (Feb. 

25, 1831)). See also Totten, 92 U.S. at 107 (refusing to examine payments from this fund lest the 

publicity make a “secret service” “impossible”). 

The interception of communications, in particular, has long been accepted as a 

fundamental method for conducting wartime surveillance. See, e.g., Greenspan, supra, at 326 

(accepted and customary means for gathering intelligence “include air reconnaissance and 

photography; ground reconnaissance; observation of enemy positions; interception of enemy 

messages, wireless and other; examination of captured documents; . . . and interrogation of 

prisoners and civilian inhabitants”) (emphasis added). Indeed, since its independence, the United 

States has intercepted communications for wartime intelligence purposes and, if necessary, has 

done so within its own borders. During the Revolutionary War, for example, George 

Washington received and used to his advantage reports from American intelligence agents on 

British military strength, British strategic intentions, and British estimates of American strength. 

See Jeffreys-Jones, supra, at 13. One source of Washington’s intelligence was intercepted 

British mail. See Central Intelligence Agency, Intelligence in the War of Independence 31, 32 

(1997). In fact, Washington himself proposed that one of his Generals “contrive a means of 

opening [British letters] without breaking the seals, take copies of the contents, and then let them 

go on.” Id. at 32 (“From that point on, Washington was privy to British intelligence pouches 

between New York and Canada.”); see generally Final Report of the Select Committee to Study 

Governmental Operations with respect to Intelligence Activities (the “Church Committee”), 

S. Rep. No. 94-755, at Book VI, 9-17 (Apr. 23, 1976) (describing Washington’s intelligence 

activities). 
16

More specifically, warrantless electronic surveillance of wartime communications has 

been conducted in the United States since electronic communications have existed, i.e., since at 

least the Civil War, when “[t]elegraph wiretapping was common, and an important intelligence 

source for both sides.” G.J.A. O’Toole, The Encyclopedia of American Intelligence and 

Espionage 498 (1988). Confederate General J.E.B. Stuart even “had his own personal 

wiretapper travel along with him in the field” to intercept military telegraphic communications. 

Samuel Dash, et al., The Eavesdroppers 23 (1971); see also O’Toole, supra, at 121, 385-88, 496-

98 (discussing Civil War surveillance methods such as wiretaps, reconnaissance balloons, 

semaphore interception, and cryptanalysis). Similarly, there was extensive use of electronic 

surveillance during the Spanish-American War. See Bruce W. Bidwell, History of the Military 

Intelligence Division, Department of the Army General Staff: 1775-1941, at 62 (1986). When an 

American expeditionary force crossed into northern Mexico to confront the forces of Pancho 

Villa in 1916, the Army “frequently intercepted messages of the regime in Mexico City or the 

forces contesting its rule.” David Alvarez, Secret Messages 6-7 (2000). Shortly after Congress 

declared war on Germany in World War I, President Wilson (citing only his constitutional 

powers and the joint resolution declaring war) ordered the censorship of messages sent outside 

the United States via submarine cables, telegraph, and telephone lines. See Exec. Order No. 

2604 (Apr. 28, 1917). During that war, wireless telegraphy “enabled each belligerent to tap the 

messages of the enemy.” Bidwell, supra, at 165 (quoting statement of Col. W. Nicolai, former 

head of the Secret Service of the High Command of the German Army, in W. Nicolai, The 

German Secret Service 21 (1924)). 

As noted in Part I, on May 21, 1940, President Roosevelt authorized warrantless 

electronic surveillance of persons suspected of subversive activities, including spying, against 

the United States. In addition, on December 8, 1941, the day after the attack on Pearl Harbor, 

President Roosevelt gave the Director of the FBI “temporary powers to direct all news 

censorship and to control all other telecommunications traffic in and out of the United States.” 

Jack A. Gottschalk, “Consistent with Security”. . . . A History of American Military Press 

Censorship, 5 Comm. & L. 35, 39 (1983) (emphasis added). See Memorandum for the 

Secretaries of War, Navy, State, and Treasury, the Postmaster General, and the Federal 

Communications Commission from Franklin D. Roosevelt (Dec. 8, 1941). President Roosevelt 

soon supplanted that temporary regime by establishing an office for conducting such electronic 

surveillance in accordance with the War Powers Act of 1941. See Pub. L. No. 77-354, § 303, 55 

Stat. 838, 840-41 (Dec. 18, 1941); Gottschalk, 5 Comm. & L. at 40. The President’s order gave 

the Government of the United States access to “communications by mail, cable, radio, or other 

means of transmission passing between the United States and any foreign country.” Id. See also 

Exec. Order No. 8985, § 1, 6 Fed. Reg. 6625, 6625 (Dec. 19, 1941). In addition, the United 

States systematically listened surreptitiously to electronic communications as part of the war 

effort. See Dash, Eavesdroppers at 30. During World War II, signals intelligence assisted in, 

among other things, the destruction of the German U-boat fleet by the Allied naval forces, see id. 

at 27, and the war against Japan, see O’Toole, supra, at 32, 323-24. In general, signals 

intelligence “helped to shorten the war by perhaps two years, reduce the loss of life, and make 

inevitable an eventual Allied victory.” Carl Boyd, American Command of the Sea Through 

Carriers, Codes, and the Silent Service: World War II and Beyond 27 (1995); see also Alvarez, 

supra, at 1 (“There can be little doubt that signals intelligence contributed significantly to the 
17

 

military defeat of the Axis.”). Significantly, not only was wiretapping in World War II used 

“extensively by military intelligence and secret service personnel in combat areas abroad,” but 

also “by the FBI and secret service in this country.” Dash, supra, at 30. 

In light of the long history of prior wartime practice, the NSA activities fit squarely 

within the sweeping terms of the AUMF. The use of signals intelligence to identify and pinpoint 

the enemy is a traditional component of wartime military operations—or, to use the terminology 

of Hamdi, a “fundamental and accepted . . . incident to war,” 542 U.S. at 518 (plurality 

opinion)—employed to defeat the enemy and to prevent enemy attacks in the United States. 

Here, as in other conflicts, the enemy may use public communications networks, and some of the 

enemy may already be in the United States. Although those factors may be present in this 

conflict to a greater degree than in the past, neither is novel. Certainly, both factors were well 

known at the time Congress enacted the AUMF. Wartime interception of international 

communications made by the enemy thus should be understood, no less than the wartime 

detention at issue in Hamdi, as one of the basic methods of engaging and defeating the enemy 

that Congress authorized in approving “all necessary and appropriate force” that the President 

would need to defend the Nation. AUMF § 2(a) (emphasis added). 

* * * 

Accordingly, the President has the authority to conduct warrantless electronic 

surveillance against the declared enemy of the United States in a time of armed conflict. That 

authority derives from the Constitution, and is reinforced by the text and purpose of the AUMF, 

the nature of the threat posed by al Qaeda that Congress authorized the President to repel, and the 

long-established understanding that electronic surveillance is a fundamental incident of the use 

of military force. The President’s power in authorizing the NSA activities is at its zenith because 

he has acted “pursuant to an express or implied authorization of Congress.” Youngstown, 343 

U.S. at 635 (Jackson, J., concurring). 

III. THE NSA ACTIVITIES ARE CONSISTENT WITH THE FOREIGN INTELLIGENCE 

SURVEILLANCE ACT

The President’s exercise of his constitutional authority to conduct warrantless wartime 

electronic surveillance of the enemy, as confirmed and supplemented by statute in the AUMF, is 

fully consistent with the requirements of the Foreign Intelligence Surveillance Act (“FISA”).5

 

FISA is a critically important tool in the War on Terror. The United States makes full use of the 

authorities available under FISA to gather foreign intelligence information, including authorities 

to intercept communications, conduct physical searches, and install and use pen registers and 

trap and trace devices. While FISA establishes certain procedures that must be followed for 

these authorities to be used (procedures that usually involve applying for and obtaining an order 

from a special court), FISA also expressly contemplates that a later legislative enactment could 

5

 To avoid revealing details about the operation of the program, it is assumed for purposes of this paper 

that the activities described by the President constitute “electronic surveillance,” as defined by FISA, 50 U.S.C. 

§ 1801(f). 
18

authorize electronic surveillance outside the procedures set forth in FISA itself. The AUMF 

constitutes precisely such an enactment. To the extent there is any ambiguity on this point, the 

canon of constitutional avoidance requires that such ambiguity be resolved in favor of the 

President’s authority to conduct the communications intelligence activities he has described. 

Finally, if FISA could not be read to allow the President to authorize the NSA activities during 

the current congressionally authorized armed conflict with al Qaeda, FISA would be 

unconstitutional as applied in this narrow context. 

A. THE REQUIREMENTS OF FISA

FISA was enacted in 1978 to regulate “electronic surveillance,” particularly when 

conducted to obtain “foreign intelligence information,” as those terms are defined in section 101 

of FISA, 50 U.S.C. § 1801. As a general matter, the statute requires that the Attorney General 

approve an application for an order from a special court composed of Article III judges and 

created by FISA—the Foreign Intelligence Surveillance Court (“FISC”). See 50 U.S.C. §§ 1803-

1804. The application must demonstrate, among other things, that there is probable cause to 

believe that the target is a foreign power or an agent of a foreign power. See id. § 1805(a)(3)(A). 

It must also contain a certification from the Assistant to the President for National Security 

Affairs or an officer of the United States appointed by the President with the advice and consent 

of the Senate and having responsibilities in the area of national security or defense that the 

information sought is foreign intelligence information and cannot reasonably be obtained by 

normal investigative means. See id. § 1804(a)(7). FISA further requires the Government to state 

the means that it proposes to use to obtain the information and the basis for its belief that the 

facilities at which the surveillance will be directed are being used or are about to be used by a 

foreign power or an agent of a foreign power. See id. § 1804(a)(4), (a)(8). 

FISA was the first congressional measure that sought to impose restrictions on the 

Executive Branch’s authority to engage in electronic surveillance for foreign intelligence 

purposes, an authority that, as noted above, had been repeatedly recognized by the federal courts. 

See Americo R. Cinquegrana, The Walls (and Wires) Have Ears: The Background and First Ten 

Years of the Foreign Intelligence Surveillance Act of 1978, 137 U. Penn. L. Rev. 793, 810 (1989) 

(stating that the “status of the President’s inherent authority” to conduct surveillance “formed the 

core of subsequent legislative deliberations” leading to the enactment of FISA). To that end, 

FISA modified a provision in Title III that previously had disclaimed any intent to have laws 

governing wiretapping interfere with the President’s constitutional authority to gather foreign 

intelligence. Prior to the passage of FISA, section 2511(3) of title 18 had stated that “[n]othing 

contained in this chapter or in section 605 of the Communications Act of 1934 . . . shall limit the 

constitutional power of the President to take such measures as he deems necessary to protect the 

Nation against actual or potential attack or other hostile acts of a foreign power, to obtain foreign 

intelligence information deemed essential to the security of the United States, or to protect 

national security information against foreign intelligence activities.” 18 U.S.C. § 2511(3) 

(1970). FISA replaced that provision with an important, though more limited, preservation of 

authority for the President. See Pub. L. No. 95-511, § 201(b), (c), 92 Stat. 1783, 1797 (1978), 

codified at 18 U.S.C. § 2511(2)(f) (West Supp. 2005) (carving out from statutory regulation only 

the acquisition of intelligence information from “international or foreign communications” and 
19

 

“foreign intelligence activities . . . involving a foreign electronic communications system” as 

long as they are accomplished “utilizing a means other than electronic surveillance as defined in 

section 101” of FISA). Congress also defined “electronic surveillance,” 50 U.S.C. § 1801(f), 

carefully and somewhat narrowly.6

In addition, Congress addressed, to some degree, the manner in which FISA might apply 

after a formal declaration of war by expressly allowing warrantless surveillance for a period of 

fifteen days following such a declaration. Section 111 of FISA allows the President to 

“authorize electronic surveillance without a court order under this subchapter to acquire foreign 

intelligence information for a period not to exceed fifteen calendar days following a declaration 

of war by the Congress.” 50 U.S.C. § 181l. 

The legislative history of FISA shows that Congress understood it was legislating on 

fragile constitutional ground and was pressing or even exceeding constitutional limits in 

regulating the President’s authority in the field of foreign intelligence. The final House 

Conference Report, for example, recognized that the statute’s restrictions might well 

impermissibly infringe on the President’s constitutional powers. That report includes the 

extraordinary acknowledgment that “[t]he conferees agree that the establishment by this act of 

exclusive means by which the President may conduct electronic surveillance does not foreclose a 

different decision by the Supreme Court.” H.R. Conf. Rep. No. 95-1720, at 35, reprinted in 

1978 U.S.C.C.A.N. 4048, 4064. But, invoking Justice Jackson’s concurrence in the Steel Seizure 

case, the Conference Report explained that Congress intended in FISA to exert whatever power 

Congress constitutionally had over the subject matter to restrict foreign intelligence surveillance 

and to leave the President solely with whatever inherent constitutional authority he might be able 

to invoke against Congress’s express wishes. Id. The Report thus explains that “[t]he intent of 

the conferees is to apply the standard set forth in Justice Jackson’s concurring opinion in the 

Steel Seizure Case: ‘When a President takes measures incompatible with the express or implied 

6

 FISA’s legislative history reveals that these provisions were intended to exclude certain intelligence 

activities conducted by the National Security Agency from the coverage of FISA. According to the report of the 

Senate Judiciary Committee on FISA, “this provision [referencing what became the first part of section 2511(2)(f)] 

is designed to make clear that the legislation does not deal with international signals intelligence activities as 

currently engaged in by the National Security Agency and electronic surveillance conducted outside the United 

States.” S. Rep. No. 95-604, at 64 (1978), reprinted in 1978 U.S.C.C.A.N. 3904, 3965. The legislative history also 

makes clear that the definition of “electronic surveillance” was crafted for the same reason. See id. at 33-34, 1978 

U.S.C.C.A.N. at 3934-36. FISA thereby “adopts the view expressed by the Attorney General during the hearings 

that enacting statutory controls to regulate the National Security Agency and the surveillance of Americans abroad 

raises problems best left to separate legislation.” Id. at 64, 1978 U.S.C.C.A.N. at 3965. Such legislation placing 

limitations on traditional NSA activities was drafted, but never passed. See National Intelligence Reorganization 

and Reform Act of 1978: Hearings Before the Senate Select Committee on Intelligence, 95th Cong., 2d Sess. 999-

1007 (1978) (text of unenacted legislation). And Congress understood that the NSA surveillance that it intended 

categorically to exclude from FISA could include the monitoring of international communications into or out of the 

United States of U.S. citizens. The report specifically referred to the Church Committee report for its description of 

the NSA’s activities, S. Rep. No. 95-604, at 64 n.63, 1978 U.S.C.C.A.N. at 3965-66 n.63, which stated that “the 

NSA intercepts messages passing over international lines of communication, some of which have one terminal 

within the United States. Traveling over these lines of communication, especially those with one terminal in the 

United States, are messages of Americans . . . .” S. Rep. 94-755, at Book II, 308 (1976). Congress’s understanding 

in the legislative history of FISA that such communications could be intercepted outside FISA procedures is notable. 
20

will of Congress, his power is at the lowest ebb, for then he can rely only upon his own 

constitutional power minus any constitutional power of Congress over the matter.’” Id. (quoting 

Youngstown Sheet & Tube Co. v. Sawyer, 343 U.S. 579, 637 (1952) (Jackson, J., concurring)); 

see also S. Rep. No. 95-604, at 64, reprinted in 1978 U.S.C.C.A.N. at 3966 (same); see generally

Elizabeth B. Bazen et al., Congressional Research Service, Re: Presidential Authority to Conduct 

Warrantless Electronic Surveillance to Gather Foreign Intelligence Information 28-29 (Jan. 5, 

2006). It is significant, however, that Congress did not decide conclusively to continue to push 

the boundaries of its constitutional authority in wartime. Instead, Congress reserved the question 

of the appropriate procedures to regulate electronic surveillance in time of war, and established a 

fifteen-day period during which the President would be permitted to engage in electronic 

surveillance without complying with FISA’s express procedures and during which Congress 

would have the opportunity to revisit the issue. See 50 U.S.C. § 1811; H.R. Conf. Rep. No. 95-

1720, at 34, reprinted in 1978 U.S.C.C.A.N. at 4063 (noting that the purpose of the fifteen-day 

period following a declaration of war in section 111 of FISA was to “allow time for 

consideration of any amendment to this act that may be appropriate during a wartime 

emergency”). 

B. FISA CONTEMPLATES AND ALLOWS SURVEILLANCE AUTHORIZED “BY 

STATUTE” 

Congress did not attempt through FISA to prohibit the Executive Branch from using 

electronic surveillance. Instead, Congress acted to bring the exercise of that power under more 

stringent congressional control. See, e.g., H. Conf. Rep. No. 95-1720, at 32, reprinted in 1978 

U.S.C.C.A.N. 4048, 4064. Congress therefore enacted a regime intended to supplant the 

President’s reliance on his own constitutional authority. Consistent with this overriding purpose 

of bringing the use of electronic surveillance under congressional control and with the 

commonsense notion that the Congress that enacted FISA could not bind future Congresses, 

FISA expressly contemplates that the Executive Branch may conduct electronic surveillance 

outside FISA’s express procedures if and when a subsequent statute authorizes such surveillance. 

Thus, section 109 of FISA prohibits any person from intentionally “engag[ing] . . . in 

electronic surveillance under color of law except as authorized by statute.” 50 U.S.C. 

§ 1809(a)(1) (emphasis added). Because FISA’s prohibitory provision broadly exempts 

surveillance “authorized by statute,” the provision demonstrates that Congress did not attempt to 

regulate through FISA electronic surveillance authorized by Congress through a subsequent 

enactment. The use of the term “statute” here is significant because it strongly suggests that any 

subsequent authorizing statute, not merely one that amends FISA itself, could legitimately 

authorize surveillance outside FISA’s standard procedural requirements. Compare 18 U.S.C. 

§ 2511(1) (“Except as otherwise specifically provided in this chapter any person who—(a) 

intentionally intercepts . . . any wire, oral, or electronic communication[] . . . shall be punished 

. . . .”) (emphasis added); id. § 2511(2)(e) (providing a defense to liability to individuals 

“conduct[ing] electronic surveillance, . . . as authorized by that Act [FISA]”) (emphasis added). 

In enacting FISA, therefore, Congress contemplated the possibility that the President might be 

permitted to conduct electronic surveillance pursuant to a later-enacted statute that did not 
21

 

incorporate all of the procedural requirements set forth in FISA or that did not expressly amend 

FISA itself. 

To be sure, the scope of this exception is rendered less clear by the conforming 

amendments that FISA made to chapter 119 of title 18—the portion of the criminal code that 

provides the mechanism for obtaining wiretaps for law enforcement purposes. Before FISA was 

enacted, chapter 119 made it a criminal offense for any person to intercept a communication 

except as specifically provided in that chapter. See 18 U.S.C. § 2511(1)(a), (4)(a). Section 

201(b) of FISA amended that chapter to provide an exception from criminal liability for 

activities conducted pursuant to FISA. Specifically, FISA added 18 U.S.C. § 2511(2)(e), which 

provides that it is not unlawful for “an officer, employee, or agent of the United States . . . to 

conduct electronic surveillance, as defined in section 101 of the Foreign Intelligence 

Surveillance Act of 1978, as authorized by that Act.” Id. § 2511(2)(e). Similarly, section 201(b) 

of FISA amended chapter 119 to provide that “procedures in this chapter [or chapter 121 

(addressing access to stored wire and electronic communications and customer records)] and the 

Foreign Intelligence Surveillance Act of 1978 shall be the exclusive means by which electronic 

surveillance, as defined in section 101 of such Act, and the interception of domestic wire, oral, 

and electronic communications may be conducted.” Id. § 2511(2)(f) (West Supp. 2005).7

The amendments that section 201(b) of FISA made to title 18 are fully consistent, 

however, with the conclusion that FISA contemplates that a subsequent statute could authorize 

electronic surveillance outside FISA’s express procedural requirements. Section 2511(2)(e) of 

title 18, which provides that it is “not unlawful” for an officer of the United States to conduct 

electronic surveillance “as authorized by” FISA, is best understood as a safe-harbor provision. 

Because of section 109, the protection offered by section 2511(2)(e) for surveillance “authorized 

by” FISA extends to surveillance that is authorized by any other statute and therefore excepted 

from the prohibition of section 109. In any event, the purpose of section 2511(2)(e) is merely to 

make explicit what would already have been implicit—that those authorized by statute to engage 

in particular surveillance do not act unlawfully when they conduct such surveillance. Thus, even 

if that provision had not been enacted, an officer conducting surveillance authorized by statute 

(whether FISA or some other law) could not reasonably have been thought to be violating Title 

III. Similarly, section 2511(2)(e) cannot be read to require a result that would be manifestly 

unreasonable—exposing a federal officer to criminal liability for engaging in surveillance 

authorized by statute, merely because the authorizing statute happens not to be FISA itself. 

Nor could 18 U.S.C. § 2511(2)(f), which provides that the “procedures in this chapter . . . 

and the Foreign Intelligence Surveillance Act of 1978 shall be the exclusive means by which 

electronic surveillance . . . may be conducted,” have been intended to trump the commonsense 

approach of section 109 and preclude a subsequent Congress from authorizing the President to 

engage in electronic surveillance through a statute other than FISA, using procedures other than 

those outlined in FISA or chapter 119 of title 18. The legislative history of section 2511(2)(f) 

clearly indicates an intent to prevent the President from engaging in surveillance except as 

7

 The bracketed portion was added in 1986 amendments to section 2511(2)(f). See Pub. L. No. 99-508 

§ 101(b)(3), 100 Stat. 1848, 1850. 
22

authorized by Congress, see H.R. Conf. Rep. No. 95-1720, at 32, reprinted in 1978 

U.S.C.C.A.N. 4048, 4064, which explains why section 2511(2)(f) set forth all then-existing 

statutory restrictions on electronic surveillance. Section 2511(2)(f)’s reference to “exclusive 

means” reflected the state of statutory authority for electronic surveillance in 1978 and cautioned 

the President not to engage in electronic surveillance outside congressionally sanctioned 

parameters. It is implausible to think that, in attempting to limit the President’s authority, 

Congress also limited its own future authority by barring subsequent Congresses from 

authorizing the Executive to engage in surveillance in ways not specifically enumerated in FISA 

or chapter 119, or by requiring a subsequent Congress specifically to amend FISA and section 

2511(2)(f). There would be a serious question as to whether the Ninety-Fifth Congress could 

have so tied the hands of its successors. See, e.g., Fletcher v. Peck, 10 U.S. (6 Cranch) 87, 135 

(1810) (noting that “one legislature cannot abridge the powers of a succeeding legislature”); 

Reichelderfer v. Quinn, 287 U.S. 315, 318 (1932) (“[T]he will of a particular Congress . . . does 

not impose itself upon those to follow in succeeding years”); Lockhart v. United States, 126 S. 

Ct. 699, 703 (2005) (Scalia, J., concurring) (collecting precedent); 1 W. Blackstone, 

Commentaries on the Laws of England 90 (1765) (“Acts of parliament derogatory from the 

power of subsequent parliaments bind not”). In the absence of a clear statement to the contrary, 

it cannot be presumed that Congress attempted to abnegate its own authority in such a way. 

Far from a clear statement of congressional intent to bind itself, there are indications that 

section 2511(2)(f) cannot be interpreted as requiring that all electronic surveillance and domestic 

interception be conducted under FISA’s enumerated procedures or those of chapter 119 of title 

18 until and unless those provisions are repealed or amended. Even when section 2511(2)(f) was 

enacted (and no subsequent authorizing statute existed), it could not reasonably be read to 

preclude all electronic surveillance conducted outside the procedures of FISA or chapter 119 of 

title 18. In 1978, use of a pen register or trap and trace device constituted electronic surveillance 

as defined by FISA. See 50 U.S.C. §§ 1801(f), (n). Title I of FISA provided procedures for 

obtaining court authorization for the use of pen registers to obtain foreign intelligence 

information. But the Supreme Court had, just prior to the enactment of FISA, held that chapter 

119 of title 18 did not govern the use of pen registers. See United States v. New York Tel. Co., 

434 U.S. 159, 165-68 (1977). Thus, if section 2511(2)(f) were to be read to permit of no 

exceptions, the use of pen registers for purposes other than to collect foreign intelligence 

information would have been unlawful because such use would not have been authorized by the 

“exclusive” procedures of section 2511(2)(f), i.e., FISA and chapter 119. But no court has held 

that pen registers could not be authorized outside the foreign intelligence context. Indeed, FISA 

appears to have recognized this issue by providing a defense to liability for any official who 

engages in electronic surveillance under a search warrant or court order. See 50 U.S.C. 

§ 1809(b). (The practice when FISA was enacted was for law enforcement officers to obtain 

search warrants under the Federal Rules of Criminal Procedure authorizing the installation and 

use of pen registers. See S. 1667, A Bill to Amend Title 18, United States Code, with Respect to 

the Interception of Certain Communications, Other Forms of Surveillance, and for Other 

Purposes: Hearing Before the Subcomm. On Patents, Copyrights and Trademarks of the Senate 
23

 

Comm. on the Judiciary, 99th Cong. 57 (1985) (prepared statement of James Knapp, Deputy 

Assistant Attorney General, Criminal Division)).8

In addition, section 2511(2)(a)(ii) authorizes telecommunications providers to assist 

officers of the Government engaged in electronic surveillance when the Attorney General 

certifies that “no warrant or court order is required by law [and] that all statutory requirements 

have been met.” 18 U.S.C. § 2511(2)(a)(ii).9

 If the Attorney General can certify, in good faith, 

that the requirements of a subsequent statute authorizing electronic surveillance are met, service 

providers are affirmatively and expressly authorized to assist the Government. Although FISA 

does allow the Government to proceed without a court order in several situations, see 50 U.S.C. 

§ 1805(f) (emergencies); id. § 1802 (certain communications between foreign governments), this 

provision specifically lists only Title III’s emergency provision but speaks generally to Attorney 

General certification. That reference to Attorney General certification is consistent with the 

historical practice in which Presidents have delegated to the Attorney General authority to 

approve warrantless surveillance for foreign intelligence purposes. See, e.g., United States v.

United States District Court, 444 F.2d 651, 669-71 (6th Cir. 1971) (reproducing as an appendix 

memoranda from Presidents Roosevelt, Truman, and Johnson). Section 2511(2)(a)(ii) thus 

suggests that telecommunications providers can be authorized to assist with warrantless 

electronic surveillance when such surveillance is authorized by law outside FISA. 

In sum, by expressly and broadly excepting from its prohibition electronic surveillance 

undertaken “as authorized by statute,” section 109 of FISA permits an exception to the 

“procedures” of FISA referred to in 18 U.S.C. § 2511(2)(f) where authorized by another statute, 

even if the other authorizing statute does not specifically amend section 2511(2)(f). 

C. THE AUMF IS A “STATUTE” AUTHORIZING SURVEILLANCE OUTSIDE THE 

CONFINES OF FISA 

The AUMF qualifies as a “statute” authorizing electronic surveillance within the meaning 

of section 109 of FISA. 

First, because the term “statute” historically has been given broad meaning, the phrase 

“authorized by statute” in section 109 of FISA must be read to include joint resolutions such as 

8

 Alternatively, section 109(b) may be read to constitute a “procedure” in FISA or to incorporate 

procedures from sources other than FISA (such as the Federal Rules of Criminal Procedure or state court 

procedures), and in that way to satisfy section 2511(2)(f). But if section 109(b)’s defense can be so read, section 

109(a) should also be read to constitute a procedure or incorporate procedures not expressly enumerated in FISA. 

9

 Section 2511(2)(a)(ii) states: 

Notwithstanding any other law, providers of wire or electronic communication service, . . . are 

authorized by law to provide information, facilities, or technical assistance to persons authorized 

by law to intercept . . . communications or to conduct electronic surveillance, as defined [by 

FISA], if such provider . . . has been provided with . . . a certification in writing by [specified 

persons proceeding under Title III’s emergency provision] or the Attorney General of the United 

States that no warrant or court order is required by law, that all statutory requirements have been 

met, and that the specific assistance is required. 
24

 

the AUMF. See American Fed’n of Labor v. Watson, 327 U. S. 582, 592-93 (1946) (finding the 

term “statute” as used in 28 U.S.C. § 380 to mean “a compendious summary of various 

enactments, by whatever method they may be adopted, to which a State gives her sanction”); 

Black’s Law Dictionary 1410 (6th ed. 1990) (defining “statute” broadly to include any “formal 

written enactment of a legislative body,” and stating that the term is used “to designate the 

legislatively created laws in contradistinction to court decided or unwritten laws”). It is thus of 

no significance to this analysis that the AUMF was enacted as a joint resolution rather than a bill. 

See, e.g., Ann Arbor R.R. Co. v. United States, 281 U.S. 658, 666 (1930) (joint resolutions are to 

be construed by applying “the rules applicable to legislation in general”); United States ex rel. 

Levey v. Stockslager, 129 U.S. 470, 475 (1889) (joint resolution had “all the characteristics and 

effects” of statute that it suspended); Padilla ex rel. Newman v. Bush, 233 F. Supp. 2d 564, 598 

(S.D.N.Y 2002) (in analyzing the AUMF, finding that there is “no relevant constitutional 

difference between a bill and a joint resolution”), rev’d sub nom. on other grounds, Rumsfeld v. 

Padilla, 352 F.3d 695 (2d Cir. 2003), rev’d, 542 U.S. 426 (2004); see also Letter for the Hon. 

John Conyers, Jr., U.S. House of Representatives, from Prof. Laurence H. Tribe at 3 (Jan. 6, 

2006) (term “statute” in section 109 of FISA “of course encompasses a joint resolution presented 

to and signed by the President”). 

Second, the longstanding history of communications intelligence as a fundamental 

incident of the use of force and the Supreme Court’s decision in Hamdi v. Rumsfeld strongly 

suggest that the AUMF satisfies the requirement of section 109 of FISA for statutory 

authorization of electronic surveillance. As explained above, it is not necessary to demarcate the 

outer limits of the AUMF to conclude that it encompasses electronic surveillance targeted at the 

enemy. Just as a majority of the Court concluded in Hamdi that the AUMF authorizes detention 

of U.S. citizens who are enemy combatants without expressly mentioning the President’s longrecognized power to detain, so too does it authorize the use of electronic surveillance without 

specifically mentioning the President’s equally long-recognized power to engage in 

communications intelligence targeted at the enemy. And just as the AUMF satisfies the 

requirement in 18 U.S.C. § 4001(a) that no U.S. citizen be detained “except pursuant to an Act of 

Congress,” so too does it satisfy section 109’s requirement for statutory authorization of 

electronic surveillance.10 In authorizing the President’s use of force in response to the 

September 11th attacks, Congress did not need to comb through the United States Code looking 

for those restrictions that it had placed on national security operations during times of peace and 

designate with specificity each traditional tool of military force that it sought to authorize the 

President to use. There is no historical precedent for such a requirement: authorizations to use 

10 It might be argued that Congress dealt more comprehensively with electronic surveillance in FISA than 

it did with detention in 18 U.S.C. § 4001(a). Thus, although Congress prohibited detention “except pursuant to an 

Act of Congress,” it combined the analogous prohibition in FISA (section 109(a)) with section 2511(2)(f)’s 

exclusivity provision. See Letter to the Hon. Bill Frist, Majority Leader, U.S. Senate, from Professor Curtis A. 

Bradley et al. at 5 n.6 (Jan. 9, 2006) (noting that section 4001(a) does not “attempt[] to create an exclusive 

mechanism for detention”). On closer examination, however, it is evident that Congress has regulated detention far 

more meticulously than these arguments suggest. Detention is the topic of much of the Criminal Code, as well as a 

variety of other statutes, including those providing for civil commitment of the mentally ill and confinement of alien 

terrorists. The existence of these statutes and accompanying extensive procedural safeguards, combined with the 

substantial constitutional issues inherent in detention, see, e.g., Hamdi, 542 U.S. at 574-75 (Scalia, J., dissenting), 

refute any such argument. 
25

 

military force traditionally have been couched in general language. Indeed, prior administrations 

have interpreted joint resolutions declaring war and authorizing the use of military force to 

authorize expansive collection of communications into and out of the United States.11

Moreover, crucial to the Framers’ decision to vest the President with primary 

constitutional authority to defend the Nation from foreign attack is the fact that the Executive can 

act quickly, decisively, and flexibly as needed. For Congress to have a role in that process, it 

must be able to act with similar speed, either to lend its support to, or to signal its disagreement 

with, proposed military action. Yet the need for prompt decisionmaking in the wake of a 

devastating attack on the United States is fundamentally inconsistent with the notion that to do so 

Congress must legislate at a level of detail more in keeping with a peacetime budget 

reconciliation bill. In emergency situations, Congress must be able to use broad language that 

effectively sanctions the President’s use of the core incidents of military force. That is precisely 

what Congress did when it passed the AUMF on September 14, 2001—just three days after the 

deadly attacks on America. The Capitol had been evacuated on September 11th, and Congress 

was meeting in scattered locations. As an account emerged of who might be responsible for 

these attacks, Congress acted quickly to authorize the President to use “all necessary and 

appropriate force” against the enemy that he determines was involved in the September 11th 

attacks. Under these circumstances, it would be unreasonable and wholly impractical to demand 

that Congress specifically amend FISA in order to assist the President in defending the Nation. 

Such specificity would also have been self-defeating because it would have apprised our 

adversaries of some of our most sensitive methods of intelligence gathering.12

Section 111 of FISA, 50 U.S.C. § 1811, which authorizes the President, 

“[n]otwithstanding any other law,” to conduct “electronic surveillance without a court order 

under this subchapter to acquire foreign intelligence information for a period not to exceed 

fifteen calendar days following a declaration of war by Congress,” does not require a different 

reading of the AUMF. See also id. § 1844 (same provision for pen registers); id. § 1829 (same 

provision for physical searches). Section 111 cannot reasonably be read as Congress’s final 

word on electronic surveillance during wartime, thus permanently limiting the President in all 

11 As noted above, in intercepting communications, President Wilson relied on his constitutional authority 

and the joint resolution declaring war and authorizing the use of military force, which, as relevant here, provided 

“that the President [is] authorized and directed to employ the entire naval and military forces of the United States 

and the resources of the Government to carry on war against the Imperial German Government; and to bring the 

conflict to a successful termination all of the resources of the country are hereby pledged by the Congress of the 

United States.” Joint Resolution of Apr. 6, 1917, ch. 1, 40 Stat. 1. The authorization did not explicitly mention 

interception of communications. 

12 Some have suggested that the Administration declined to seek a specific amendment to FISA allowing 

the NSA activities “because it was advised that Congress would reject such an amendment,” Letter to the Hon. Bill 

Frist, Majority Leader, U.S. Senate, from Professor Curtis A. Bradley et al. 4 & n.4 (Jan. 9, 2005), and they have 

quoted in support of that assertion the Attorney General’s statement that certain Members of Congress advised the 

Administration that legislative relief “would be difficult, if not impossible.” Id. at 4 n.4. As the Attorney General 

subsequently indicated, however, the difficulty with such specific legislation was that it could not be enacted 

“without compromising the program.” See Remarks by Homeland Security Secretary Chertoff and Attorney 

General Gonzales on the USA PATRIOT Act (Dec. 21, 2005), available at http://www.dhs.gov/dhspublic/ 

display?content=5285. 
26

circumstances to a mere fifteen days of warrantless military intelligence gathering targeted at the 

enemy following a declaration of war. Rather, section 111 represents Congress’s recognition 

that it would likely have to return to the subject and provide additional authorization to conduct 

warrantless electronic surveillance outside FISA during time of war. The Conference Report 

explicitly stated the conferees’ “inten[t] that this [fifteen-day] period will allow time for 

consideration of any amendment to this act that may be appropriate during a wartime 

emergency.” H.R. Conf. Rep. No. 95-1720, at 34, reprinted in 1978 U.S.C.C.A.N. at 4063. 

Congress enacted section 111 so that the President could conduct warrantless surveillance while 

Congress considered supplemental wartime legislation. 

Nothing in the terms of section 111 disables Congress from authorizing such electronic 

surveillance as a traditional incident of war through a broad, conflict-specific authorization for 

the use of military force, such as the AUMF. Although the legislative history of section 111 

indicates that in 1978 some Members of Congress believed that any such authorization would 

come in the form of a particularized amendment to FISA itself, section 111 does not require that 

result. Nor could the Ninety-Fifth Congress tie the hands of a subsequent Congress in this way, 

at least in the absence of far clearer statutory language expressly requiring that result. See supra, 

pp. 21-22; compare, e.g., War Powers Resolution, § 8, 50 U.S.C. § 1547(a) (“Authority to 

introduce United States Armed Forces into hostilities . . . shall not be inferred . . . from any 

provision of law . . . unless such provision specifically authorizes [such] introduction . . . and 

states that it is intended to constitute specific statutory authorization within the meaning of this 

chapter.”); 10 U.S.C. § 401 (stating that any other provision of law providing assistance to 

foreign countries to detect and clear landmines shall be subject to specific limitations and may be 

construed as superseding such limitations “only if, and to the extent that, such provision 

specifically refers to this section and specifically identifies the provision of this section that is to 

be considered superseded or otherwise inapplicable”). An interpretation of section 111 that 

would disable Congress from authorizing broader electronic surveillance in that form can be 

reconciled neither with the purposes of section 111 nor with the well-established proposition that 

“one legislature cannot abridge the powers of a succeeding legislature.” Fletcher v. Peck, 10 

U.S. (6 Cranch) at 135; see supra Part II.B. For these reasons, the better interpretation is that 

section 111 was not intended to, and did not, foreclose Congress from using the AUMF as the 

legal vehicle for supplementing the President’s existing authority under FISA in the battle 

against al Qaeda. 

The contrary interpretation of section 111 also ignores the important differences between 

a formal declaration of war and a resolution such as the AUMF. As a historical matter, a formal 

declaration of war was no longer than a sentence, and thus Congress would not expect a 

declaration of war to outline the extent to which Congress authorized the President to engage in 

various incidents of waging war. Authorizations for the use of military force, by contrast, are 

typically more detailed and are made for the specific purpose of reciting the manner in which 

Congress has authorized the President to act. Thus, Congress could reasonably expect that an 

authorization for the use of military force would address the issue of wartime surveillance, while 

a declaration of war would not. Here, the AUMF declares that the Nation faces “an unusual and 

extraordinary threat,” acknowledges that “the President has authority under the Constitution to 

take action to deter and prevent acts of international terrorism against the United States,” and 
27

 

provides that the President is authorized “to use all necessary and appropriate force” against 

those “he determines” are linked to the September 11th attacks. AUMF pmbl., § 2. This 

sweeping language goes far beyond the bare terms of a declaration of war. Compare, e.g., Act of 

Apr. 25, 1898, ch. 189, 30 Stat. 364 (“First. That war be, and the same is hereby declared to 

exist . . . between the United States of America and the Kingdom of Spain.”). 

Although legislation that has included a declaration of war has often also included an 

authorization of the President to use force, these provisions are separate and need not be 

combined in a single statute. See, e.g., id. (“Second. That the President of the United States be, 

and he hereby is, directed and empowered to use the entire land and naval forces of the United 

States, and to call into the actual service of the United States the militia of the several states, to 

such extent as may be necessary to carry this Act into effect.”) (emphasis added). Moreover, 

declarations of war have legal significance independent of any additional authorization of force 

that might follow. See, e.g., Louis Henkin, Foreign Affairs and the U.S. Constitution 75 (2d ed. 

1996) (explaining that a formal state of war has various legal effects, such as terminating 

diplomatic relations, and abrogating or suspending treaty obligations and international law rights 

and duties); see also id. at 370 n.65 (speculating that one reason to fight an undeclared war 

would be to “avoid the traditional consequences of declared war on relations with third nations 

or even . . . belligerents”). 

In addition, section 111 does not cover the vast majority of modern military conflicts. 

The last declared war was World War II. Indeed, the most recent conflict prior to the passage of 

FISA, Vietnam, was fought without a formal declaration of war. In addition, the War Powers 

Resolution, enacted less than five years before FISA, clearly recognizes the distinctions between 

formal declarations of war and authorizations of force and demonstrates that, if Congress had 

wanted to include such authorizations in section 111, it knew how to do so. See, e.g., 50 U.S.C. 

§ 1544(b) (attempting to impose certain consequences 60 days after reporting the initiation of 

hostilities to Congress “unless the Congress . . . has declared war or has enacted a specific 

authorization for such use” of military force) (emphasis added). It is possible that, in enacting 

section 111, Congress intended to make no provision for even the temporary use of electronic 

surveillance without a court order for what had become the legal regime for most military 

conflicts. A better reading, however, is that Congress assumed that such a default provision 

would be unnecessary because, if it had acted through an authorization for the use of military 

force, the more detailed provisions of that authorization would resolve the extent to which 

Congress would attempt to authorize, or withhold authorization for, the use of electronic 

surveillance.13

13 Some have pointed to the specific amendments to FISA that Congress made shortly after September 

11th in the USA PATRIOT Act, Pub. L. No. 107-56, §§ 204, 218, 115 Stat. 272, 281, 291 (2001), to argue that 

Congress did not contemplate electronic surveillance outside the parameters of FISA. See Memorandum for 

Members of the House Permanent Select Comm. on Intel. from Jeffrey H. Smith, Re: Legal Authorities Regarding 

Warrantless Surveillance of U.S. Persons 6-7 (Jan. 3, 2006). The USA PATRIOT Act amendments, however, do 

not justify giving the AUMF an unnaturally narrow reading. The USA PATRIOT Act amendments made important 

corrections in the general application of FISA; they were not intended to define the precise incidents of military 

force that would be available to the President in prosecuting the current armed conflict against al Qaeda and its 

allies. Many removed long-standing impediments to the effectiveness of FISA that had contributed to the 
28

 

* * * 

The broad text of the AUMF, the authoritative interpretation that the Supreme Court gave 

it in Hamdi, and the circumstances in which it was passed demonstrate that the AUMF is a 

statute authorizing electronic surveillance under section 109 of FISA. When the President 

authorizes electronic surveillance against the enemy pursuant to the AUMF, he is therefore 

acting at the height of his authority under Youngstown, 343 U.S. at 637 (Jackson, J., concurring). 

D. THE CANON OF CONSTITUTIONAL AVOIDANCE REQUIRES RESOLVING IN FAVOR 

OF THE PRESIDENT’S AUTHORITY ANY AMBIGUITY ABOUT WHETHER FISA

FORBIDS THE NSA ACTIVITIES

As explained above, the AUMF fully authorizes the NSA activities. Because FISA 

contemplates the possibility that subsequent statutes could authorize electronic surveillance 

without requiring FISA’s standard procedures, the NSA activities are also consistent with FISA 

and related provisions in title 18. Nevertheless, some might argue that sections 109 and 111 of 

FISA, along with section 2511(2)(f)’s “exclusivity” provision and section 2511(2)(e)’s liability 

exception for officers engaged in FISA-authorized surveillance, are best read to suggest that 

FISA requires that subsequent authorizing legislation specifically amend FISA in order to free 

the Executive from FISA’s enumerated procedures. As detailed above, this is not the better 

reading of FISA. But even if these provisions were ambiguous, any doubt as to whether the 

AUMF and FISA should be understood to allow the President to make tactical military decisions 

to authorize surveillance outside the parameters of FISA must be resolved to avoid the serious 

constitutional questions that a contrary interpretation would raise. 

It is well established that the first task of any interpreter faced with a statute that may 

present an unconstitutional infringement on the powers of the President is to determine whether 

the statute may be construed to avoid the constitutional difficulty. “[I]f an otherwise acceptable 

maintenance of an unnecessary “wall” between foreign intelligence gathering and criminal law enforcement; others 

were technical clarifications. See In re Sealed Case, 310 F.3d 717, 725-30 (Foreign Int. Surv. Ct. Rev. 2002). The 

“wall” had been identified as a significant problem hampering the Government’s efficient use of foreign intelligence 

information well before the September 11th attacks and in contexts unrelated to terrorism. See, e.g., Final Report of 

the Attorney General’s Review Team on the Handling of the Los Alamos National Laboratory Investigation 710, 

729, 732 (May 2000); General Accounting Office, FBI Intelligence Investigations: Coordination Within Justice on 

Counterintelligence Criminal Matters Is Limited (GAO-01-780) 3, 31 (July 2001). Finally, it is worth noting that 

Justice Souter made a similar argument in Hamdi that the USA PATRIOT Act all but compelled a narrow reading of 

the AUMF. See 542 U.S. at 551 (“It is very difficult to believe that the same Congress that carefully circumscribed 

Executive power over alien terrorists on home soil [in the USA PATRIOT Act] would not have meant to require the 

Government to justify clearly its detention of an American citizen held on home soil incommunicado.”). Only 

Justice Ginsburg joined this opinion, and the position was rejected by a majority of Justices. 

Nor do later amendments to FISA undermine the conclusion that the AUMF authorizes electronic 

surveillance outside the procedures of FISA. Three months after the enactment of the AUMF, Congress enacted 

certain “technical amendments” to FISA which, inter alia, extended the time during which the Attorney General 

may issue an emergency authorization of electronic surveillance from 24 to 72 hours. See Intelligence Authorization 

Act for Fiscal Year 2002, Pub. L. No. 107-108, § 314, 115 Stat. 1394, 1402 (2001). These modifications to FISA do 

not in any way undermine Congress’s previous authorization in the AUMF for the President to engage in electronic 

surveillance outside the parameters of FISA in the specific context of the armed conflict with al Qaeda. 
29

construction of a statute would raise serious constitutional problems, and where an alternative 

interpretation of the statute is ‘fairly possible,’ we are obligated to construe the statute to avoid 

such problems.” INS v. St. Cyr, 533 U.S. 289, 299-300 (2001) (citations omitted); Ashwander v.

TVA, 297 U.S. 288, 345-48 (1936) (Brandeis, J., concurring). Moreover, the canon of 

constitutional avoidance has particular importance in the realm of national security, where the 

President’s constitutional authority is at its highest. See Department of the Navy v. Egan, 484

U.S. 518, 527, 530 (1988); William N. Eskridge, Jr., Dynamic Statutory Interpretation 325 

(1994) (describing “[s]uper-strong rule against congressional interference with the President’s 

authority over foreign affairs and national security”). Thus, courts and the Executive Branch 

typically construe a general statute, even one that is written in unqualified terms, to be implicitly 

limited so as not to infringe on the President’s Commander in Chief powers. 

Reading FISA to prohibit the NSA activities would raise two serious constitutional 

questions, both of which must be avoided if possible: (1) whether the signals intelligence 

collection the President determined was necessary to undertake is such a core exercise of 

Commander in Chief control over the Armed Forces during armed conflict that Congress cannot 

interfere with it at all and (2) whether the particular restrictions imposed by FISA are such that 

their application would impermissibly impede the President’s exercise of his constitutionally 

assigned duties as Commander in Chief. Constitutional avoidance principles require interpreting 

FISA, at least in the context of the military conflict authorized by the AUMF, to avoid these 

questions, if “fairly possible.” Even if Congress intended FISA to use the full extent of its 

constitutional authority to “occupy the field” of “electronic surveillance,” as FISA used that 

term, during peacetime, the legislative history indicates that Congress had not reached a 

definitive conclusion about its regulation during wartime. See H.R. Conf. Rep. No. 95-1720, at 

34, reprinted in 1978 U.S.C.C.A.N. at 4063 (noting that the purpose of the fifteen-day period 

following a declaration of war in section 111 of FISA was to “allow time for consideration of 

any amendment to this act that may be appropriate during a wartime emergency”). Therefore, it 

is not clear that Congress, in fact, intended to test the limits of its constitutional authority in the 

context of wartime electronic surveillance. 

Whether Congress may interfere with the President’s constitutional authority to collect 

foreign intelligence information through interception of communications reasonably believed to 

be linked to the enemy poses a difficult constitutional question. As explained in Part I, it had 

long been accepted at the time of FISA’s enactment that the President has inherent constitutional 

authority to conduct warrantless electronic surveillance for foreign intelligence purposes. 

Congress recognized at the time that the enactment of a statute purporting to eliminate the 

President’s ability, even during peacetime, to conduct warrantless electronic surveillance to 

collect foreign intelligence was near or perhaps beyond the limit of Congress’s Article I powers. 

The NSA activities, however, involve signals intelligence performed in the midst of a 

congressionally authorized armed conflict undertaken to prevent further hostile attacks on the 

United States. The NSA activities lie at the very core of the Commander in Chief power, 

especially in light of the AUMF’s explicit authorization for the President to take all necessary 

and appropriate military action to stop al Qaeda from striking again. The constitutional 

principles at stake here thus involve not merely the President’s well-established inherent 
30

authority to conduct warrantless surveillance for foreign intelligence purposes during peacetime, 

but also the powers and duties expressly conferred on him as Commander in Chief by Article II. 

Even outside the context of wartime surveillance of the enemy, the source and scope of 

Congress’s power to restrict the President’s inherent authority to conduct foreign intelligence 

surveillance is unclear. As explained above, the President’s role as sole organ for the Nation in 

foreign affairs has long been recognized as carrying with it preeminent authority in the field of 

national security and foreign intelligence. The source of this authority traces to the Vesting 

Clause of Article II, which states that “[t]he executive Power shall be vested in a President of the 

United States of America.” U.S. Const. art. II, § 1. The Vesting Clause “has long been held to 

confer on the President plenary authority to represent the United States and to pursue its interests 

outside the borders of the country, subject only to limits specifically set forth in the Constitution 

itself and to such statutory limitations as the Constitution permits Congress to impose by 

exercising one of its enumerated powers.” The President’s Compliance with the “Timely 

Notification” Requirement of Section 501(b) of the National Security Act, 10 Op. O.L.C. 159, 

160-61 (1986) (“Timely Notification Requirement Op.”). 

Moreover, it is clear that some presidential authorities in this context are beyond 

Congress’s ability to regulate. For example, as the Supreme Court explained in Curtiss-Wright, 

the President “makes treaties with the advice and consent of the Senate; but he alone negotiates. 

Into the field of negotiation the Senate cannot intrude; and Congress itself is powerless to invade 

it.” 299 U.S. at 319. Similarly, President Washington established early in the history of the 

Republic the Executive’s absolute authority to maintain the secrecy of negotiations with foreign 

powers, even against congressional efforts to secure information. See id. at 320-21. 

Recognizing presidential authority in this field, the Executive Branch has taken the position that 

“congressional legislation authorizing extraterritorial diplomatic and intelligence activities is 

superfluous, and . . . statutes infringing the President’s inherent Article II authority would be 

unconstitutional.” Timely Notification Requirement Op., 10 Op. O.L.C. at 164. 

There are certainly constitutional limits on Congress’s ability to interfere with the 

President’s power to conduct foreign intelligence searches, consistent with the Constitution, 

within the United States. As explained above, intelligence gathering is at the heart of executive 

functions. Since the time of the Founding it has been recognized that matters requiring 

secrecy—and intelligence in particular—are quintessentially executive functions. See, e.g., The 

Federalist No. 64, at 435 (John Jay) (Jacob E. Cooke ed. 1961) (“The convention have done well 

therefore in so disposing of the power of making treaties, that although the president must in 

forming them act by the advice and consent of the senate, yet he will be able to manage the 

business of intelligence in such manner as prudence may suggest.”); see also Timely Notification 

Requirement Op., 10 Op. O.L.C. at 165; cf. New York Times Co. v. United States, 403 U.S. 713, 

729-30 (1971) (Stewart, J., concurring) (“[I]t is the constitutional duty of the Executive—as a 

matter of sovereign prerogative and not as a matter of law as the courts know law—through the 

promulgation and enforcement of executive regulations, to protect the confidentiality necessary 

to carry out its responsibilities in the field of international relations and national defense.”). 
31

 

Because Congress has rarely attempted to intrude in this area and because many of these 

questions are not susceptible to judicial review, there are few guideposts for determining exactly 

where the line defining the President’s sphere of exclusive authority lies. Typically, if a statute 

is in danger of encroaching upon exclusive powers of the President, the courts apply the 

constitutional avoidance canon, if a construction avoiding the constitutional issue is “fairly 

possible.” See, e.g., Egan, 484 U.S. at 527, 530. The only court that squarely has addressed the 

relative powers of Congress and the President in this field suggested that the balance tips 

decidedly in the President’s favor. The Foreign Intelligence Surveillance Court of Review 

recently noted that all courts to have addressed the issue of the President’s inherent authority 

have “held that the President did have inherent authority to conduct warrantless searches to 

obtain foreign intelligence information.” In re Sealed Case, 310 F.3d 717, 742 (Foreign Intel. 

Surv. Ct. of Rev. 2002). On the basis of that unbroken line of precedent, the court “[took] for 

granted that the President does have that authority,” and concluded that, “assuming that is so, 

FISA could not encroach on the President’s constitutional power.” Id.14 Although the court did 

not provide extensive analysis, it is the only judicial statement on point, and it comes from the 

specialized appellate court created expressly to deal with foreign intelligence issues under FISA. 

But the NSA activities are not simply exercises of the President’s general foreign affairs 

powers. Rather, they are primarily an exercise of the President’s authority as Commander in 

Chief during an armed conflict that Congress expressly has authorized the President to pursue. 

The NSA activities, moreover, have been undertaken specifically to prevent a renewed attack at 

the hands of an enemy that has already inflicted the single deadliest foreign attack in the Nation’s 

history. The core of the Commander in Chief power is the authority to direct the Armed Forces 

in conducting a military campaign. Thus, the Supreme Court has made clear that the “President 

alone” is “constitutionally invested with the entire charge of hostile operations.” Hamilton v.

Dillin, 88 U.S. (21 Wall.) 73, 87 (1874); The Federalist No. 74, at 500 (Alexander Hamilton). 

“As commander-in-chief, [the President] is authorized to direct the movements of the naval and 

military forces placed by law at his command, and to employ them in the manner he may deem 

most effectual to harass and conquer and subdue the enemy.” Fleming v. Page, 50 U.S. (9 How.) 

603, 615 (1850). As Chief Justice Chase explained in 1866, although Congress has authority to 

legislate to support the prosecution of a war, Congress may not “interfere[] with the command of 

the forces and the conduct of campaigns. That power and duty belong to the President as 

commander-in-chief.” Ex parte Milligan, 71 U.S. (4 Wall.) 2, 139 (1866) (Chase, C.J., 

concurring in judgment) (emphasis added). 

The Executive Branch uniformly has construed the Commander in Chief and foreign 

affairs powers to grant the President authority that is beyond the ability of Congress to regulate. 

In 1860, Attorney General Black concluded that an act of Congress, if intended to constrain the 

President’s discretion in assigning duties to an officer in the army, would be unconstitutional: 

As commander-in-chief of the army it is your right to decide according to your 

14 In the past, other courts have declined to express a view on that issue one way or the other. See, e.g., 

Butenko, 494 F.2d at 601 (“We do not intimate, at this time, any view whatsoever as the proper resolution of the 

possible clash of the constitutional powers of the President and Congress.”). 
32

 

own judgment what officer shall perform any particular duty, and as the supreme 

executive magistrate you have the power of appointment. Congress could not, if 

it would, take away from the President, or in anywise diminish the authority 

conferred upon him by the Constitution. 

Memorial of Captain Meigs, 9 Op. Att’y Gen. 462, 468 (1860). Attorney General Black went on 

to explain that, in his view, the statute involved there could probably be read as simply providing 

“a recommendation” that the President could decline to follow at his discretion. Id. at 469-70.15

Supreme Court precedent does not support claims of congressional authority over core 

military decisions during armed conflicts. In particular, the two decisions of the Supreme Court 

that address a conflict between asserted wartime powers of the Commander in Chief and 

congressional legislation and that resolve the conflict in favor of Congress—Little v. Barreme, 6 

U.S. (2 Cranch) 170 (1804), and Youngstown Sheet & Tube Co. v. Sawyer, 343 U.S. 579 

(1952)—are both distinguishable from the situation presented by the NSA activities in the 

conflict with al Qaeda. Neither supports the constitutionality of the restrictions in FISA as 

applied here. 

Barreme involved a suit brought to recover a ship seized by an officer of the U.S. Navy 

on the high seas during the so-called “Quasi War” with France in 1799. The seizure had been 

based upon the officer’s orders implementing an act of Congress suspending commerce between 

the United States and France and authorizing the seizure of American ships bound to a French 

port. The ship in question was suspected of sailing from a French port. The Supreme Court held 

that the orders given by the President could not authorize a seizure beyond the terms of the 

15 Executive practice recognizes, consistent with the Constitution, some congressional control over the 

Executive’s decisions concerning the Armed Forces. See, e.g., U.S. Const. art. I, § 8, cl. 12 (granting Congress 

power “to raise and support Armies”). But such examples have not involved congressional attempts to regulate the 

actual conduct of a military campaign, and there is no comparable textual support for such interference. For 

example, just before World War II, Attorney General Robert Jackson concluded that the Neutrality Act prohibited 

President Roosevelt from selling certain armed naval vessels and sending them to Great Britain. See Acquisition of 

Naval and Air Bases in Exchange for Over-Age Destroyers, 39 Op. Att’y Gen. 484, 496 (1940). Jackson’s apparent 

conclusion that Congress could control the President’s ability to transfer war material does not imply acceptance of 

direct congressional regulation of the Commander in Chief’s control of the means and methods of engaging the 

enemy in conflict. Similarly, in Youngstown Sheet & Tube Co. v. Sawyer, the Truman Administration readily 

conceded that, if Congress had prohibited the seizure of steel mills by statute, Congress’s action would have been 

controlling. See Brief for Petitioner at 150, Youngstown, 343 U.S. 579 (1952) (Nos. 744 and 745). This concession 

implies nothing concerning congressional control over the methods of engaging the enemy. 

Likewise, the fact that the Executive Branch has, at times, sought congressional ratification after taking 

unilateral action in a wartime emergency does not reflect a concession that the Executive lacks authority in this area. 

A decision to seek congressional support can be prompted by many motivations, including a desire for political 

support. In modern times, several administrations have sought congressional authorization for the use of military 

force while preserving the ability to assert the unconstitutionality of the War Powers Resolution. See, e.g., 

Statement on Signing the Resolution Authorizing the Use of Military Force Against Iraq, 1 Pub. Papers of George 

Bush 40 (1991) (“[M]y request for congressional support did not . . . constitute any change in the long-standing 

positions of the executive branch on either the President’s constitutional authority to use the Armed Forces to defend 

vital U.S. interests or the constitutionality of the War Powers Resolution.”). Moreover, many actions for which 

congressional support has been sought—such as President Lincoln’s action in raising an Army in 1861—quite likely 

fall primarily under Congress’s core Article I powers. 
33

statute and therefore that the seizure of the ship not in fact bound to a French port was unlawful. 

See 6 U.S. at 177-78. Although some commentators have broadly characterized Barreme as 

standing for the proposition that Congress may restrict by statute the means by which the 

President can direct the Nation’s Armed Forces to carry on a war, the Court’s holding was 

limited in at least two significant ways. First, the operative section of the statute in question 

applied only to American merchant ships. See id. at 170 (quoting Act of February 9, 1799). 

Thus, the Court simply had no occasion to rule on whether, even in the limited and peculiar 

circumstances of the Quasi War, Congress could have placed some restriction on the orders the 

Commander in Chief could issue concerning direct engagements with enemy forces. Second, it 

is significant that the statute in Barreme was cast expressly, not as a limitation on the conduct of 

warfare by the President, but rather as regulation of a subject within the core of Congress’s 

enumerated powers under Article I—the regulation of foreign commerce. See U.S. Const., art. I, 

§ 8, cl. 3. The basis of Congress’s authority to act was therefore clearer in Barreme than it is 

here. 

Youngstown involved an effort by the President—in the face of a threatened work 

stoppage—to seize and to run steel mills. Congress had expressly considered the possibility of 

giving the President power to effect such a seizure during national emergencies. It rejected that 

option, however, instead providing different mechanisms for resolving labor disputes and 

mechanisms for seizing industries to ensure production vital to national defense. 

For the Court, the connection between the seizure and the core Commander in Chief 

function of commanding the Armed Forces was too attenuated. The Court pointed out that the 

case did not involve authority over “day-to-day fighting in a theater of war.” Id. at 587. Instead, 

it involved a dramatic extension of the President’s authority over military operations to exercise 

control over an industry that was vital for producing equipment needed overseas. Justice 

Jackson’s concurring opinion also reveals a concern for what might be termed foreign-todomestic presidential bootstrapping. The United States became involved in the Korean conflict 

through President Truman’s unilateral decision to commit troops to the defense of South Korea. 

The President then claimed authority, based upon this foreign conflict, to extend presidential 

control into vast sectors of the domestic economy. Justice Jackson expressed “alarm[]” at a 

theory under which “a President whose conduct of foreign affairs is so largely uncontrolled, and 

often even is unknown, can vastly enlarge his mastery over the internal affairs of the country by 

his own commitment of the Nation’s armed forces to some foreign venture.” Id. at 642. 

Moreover, President Truman’s action extended the President’s authority into a field that 

the Constitution predominantly assigns to Congress. See id. at 588 (discussing Congress’s 

commerce power and noting that “[t]he Constitution does not subject this lawmaking power of 

Congress to presidential or military supervision or control”); see also id. at 643 (Jackson, J., 

concurring) (explaining that Congress is given express authority to “‘raise and support Armies’” 

and “‘to provide and maintain a Navy’”) (quoting U.S. Const. art. I, § 8, cls. 12, 13). Thus, 

Youngstown involved an assertion of executive power that not only stretched far beyond the 
34

 

President’s core Commander in Chief functions, but that did so by intruding into areas where 

Congress had been given an express, and apparently dominant, role by the Constitution.16

The present situation differs dramatically. The exercise of executive authority involved 

in the NSA activities is not several steps removed from the actual conduct of a military 

campaign. As explained above, it is an essential part of the military campaign. Unlike the 

activities at issue in Youngstown, the NSA activities are directed at the enemy, and not at 

domestic activity that might incidentally aid the war effort. And assertion of executive authority 

here does not involve extending presidential power into areas reserved for Congress. Moreover, 

the theme that appeared most strongly in Justice Jackson’s concurrence in Youngstown—the fear 

of presidential bootstrapping—does not apply in this context. Whereas President Truman had 

used his inherent constitutional authority to commit U.S. troops, here Congress expressly 

provided the President sweeping authority to use “all necessary and appropriate force” to protect 

the Nation from further attack. AUMF § 2(a). There is thus no bootstrapping concern. 

Finally, Youngstown cannot be read to suggest that the President’s authority for engaging 

the enemy is less extensive inside the United States than abroad. To the contrary, the extent of 

the President’s Commander in Chief authority necessarily depends on where the enemy is found 

and where the battle is waged. In World War II, for example, the Supreme Court recognized that 

the President’s authority as Commander in Chief, as supplemented by Congress, included the 

power to capture and try agents of the enemy in the United States, even if they never had 

“entered the theatre or zone of active military operations.” Quirin, 317 U.S. at 38.17 In the 

present conflict, unlike in the Korean War, the battlefield was brought to the United States in the 

most literal way, and the United States continues to face a threat of further attacks on its soil. In 

short, therefore, Youngstown does not support the view that Congress may constitutionally 

prohibit the President from authorizing the NSA activities. 

The second serious constitutional question is whether the particular restrictions imposed 

by FISA would impermissibly hamper the President’s exercise of his constitutionally assigned 

duties as Commander in Chief. The President has determined that the speed and agility required 

to carry out the NSA activities successfully could not have been achieved under FISA.18 

Because the President also has determined that the NSA activities are necessary to the defense of 

16 Youngstown does demonstrate that the mere fact that Executive action might be placed in Justice 

Jackson’s category III does not obviate the need for further analysis. Justice Jackson’s framework therefore 

recognizes that Congress might impermissibly interfere with the President’s authority as Commander in Chief or to 

conduct the Nation’s foreign affairs. 

17 It had been recognized long before Youngstown that, in a large-scale conflict, the area of operations 

could readily extend to the continental United States, even when there are no major engagements of armed forces 

here. Thus, in the context of the trial of a German officer for spying in World War I, it was recognized that “[w]ith 

the progress made in obtaining ways and means for devastation and destruction, the territory of the United States 

was certainly within the field of active operations” during the war, particularly in the port of New York, and that a 

spy in the United States might easily have aided the “hostile operation” of U-boats off the coast. United States ex 

reI. Wessels v. McDonald, 265 F. 754, 764 (E.D.N.Y. 1920). 

18 In order to avoid further compromising vital national security activities, a full explanation of the basis 

for the President’s determination cannot be given in an unclassified document. 
35

 

the United States from a subsequent terrorist attack in the armed conflict with al Qaeda, FISA 

would impermissibly interfere with the President’s most solemn constitutional obligation—to 

defend the United States against foreign attack. 

Indeed, if an interpretation of FISA that allows the President to conduct the NSA 

activities were not “fairly possible,” FISA would be unconstitutional as applied in the context of 

this congressionally authorized armed conflict. In that event, FISA would purport to prohibit the 

President from undertaking actions necessary to fulfill his constitutional obligation to protect the 

Nation from foreign attack in the context of a congressionally authorized armed conflict with an 

enemy that has already staged the most deadly foreign attack in our Nation’s history. A statute 

may not “impede the President’s ability to perform his constitutional duty,” Morrison v. Olson, 

487 U.S. 654, 691 (1988) (emphasis added); see also id. at 696-97, particularly not the 

President’s most solemn constitutional obligation—the defense of the Nation. See also In re 

Sealed Case, 310 F.3d at 742 (explaining that “FISA could not encroach on the President’s 

constitutional power”). 

Application of the avoidance canon would be especially appropriate here for several 

reasons beyond the acute constitutional crises that would otherwise result. First, as noted, 

Congress did not intend FISA to be the final word on electronic surveillance conducted during 

armed conflicts. Instead, Congress expected that it would revisit the subject in subsequent 

legislation. Whatever intent can be gleaned from FISA’s text and legislative history to set forth a 

comprehensive scheme for regulating electronic surveillance during peacetime, that same intent 

simply does not extend to armed conflicts and declared wars.19 Second, FISA was enacted 

during the Cold War, not during active hostilities with an adversary whose mode of operation is 

to blend in with the civilian population until it is ready to strike. These changed circumstances 

have seriously altered the constitutional calculus, one that FISA’s enactors had already 

recognized might suggest that the statute was unconstitutional. Third, certain technological 

changes have rendered FISA still more problematic. As discussed above, when FISA was 

enacted in 1978, Congress expressly declined to regulate through FISA certain signals 

intelligence activities conducted by the NSA. See supra, at pp. 18-19 & n.6.20 These same 

factors weigh heavily in favor of concluding that FISA would be unconstitutional as applied to 

the current conflict if the canon of constitutional avoidance could not be used to head off a 

collision between the Branches. 

19 FISA exempts the President from its procedures for fifteen days following a congressional declaration of 

war. See 50 U.S.C. § 1811. If an adversary succeeded in a decapitation strike, preventing Congress from declaring 

war or passing subsequent authorizing legislation, it seems clear that FISA could not constitutionally continue to 

apply in such circumstances. 

20 Since FISA’s enactment in 1978, the means of transmitting communications has undergone extensive 

transformation. In particular, many communications that would have been carried by wire are now transmitted 

through the air, and many communications that would have been carried by radio signals (including by satellite 

transmissions) are now transmitted by fiber optic cables. It is such technological advancements that have broadened 

FISA’s reach, not any particularized congressional judgment that the NSA’s traditional activities in intercepting 

such international communications should be subject to FISA’s procedures. A full explanation of these 

technological changes would require a discussion of classified information. 
36

 

* * * 

As explained above, FISA is best interpreted to allow a statute such as the AUMF to 

authorize electronic surveillance outside FISA’s enumerated procedures. The strongest 

counterarguments to this conclusion are that various provisions in FISA and title 18, including 

section 111 of FISA and section 2511(2)(f) of title 18, together require that subsequent 

legislation must reference or amend FISA in order to authorize electronic surveillance outside 

FISA’s procedures and that interpreting the AUMF as a statute authorizing electronic 

surveillance outside FISA procedures amounts to a disfavored repeal by implication. At the very 

least, however, interpreting FISA to allow a subsequent statute such as the AUMF to authorize 

electronic surveillance without following FISA’s express procedures is “fairly possible,” and that 

is all that is required for purposes of invoking constitutional avoidance. In the competition of 

competing canons, particularly in the context of an ongoing armed conflict, the constitutional 

avoidance canon carries much greater interpretative force.21

IV. THE NSA ACTIVITIES ARE CONSISTENT WITH THE FOURTH AMENDMENT 

The Fourth Amendment prohibits “unreasonable searches and seizures” and directs that 

“no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and 

21 If the text of FISA were clear that nothing other than an amendment to FISA could authorize additional 

electronic surveillance, the AUMF would impliedly repeal as much of FISA as would prevent the President from 

using “all necessary and appropriate force” in order to prevent al Qaeda and its allies from launching another 

terrorist attack against the United States. To be sure, repeals by implication are disfavored and are generally not 

found whenever two statutes are “capable of co-existence.” Ruckelshaus v. Monsanto Co., 467 U.S. 986, 1018 

(1984). Under this standard, an implied repeal may be found where one statute would “unduly interfere with” the 

operation of another. Radzanower v. Touche Ross & Co., 426 U.S. 148, 156 (1976). The President’s determination 

that electronic surveillance of al Qaeda outside the confines of FISA was “necessary and appropriate” would create a 

clear conflict between the AUMF and FISA. FISA’s restrictions on the use of electronic surveillance would 

preclude the President from doing what the AUMF specifically authorized him to do: use all “necessary and 

appropriate force” to prevent al Qaeda from carrying out future attacks against the United States. The ordinary 

restrictions in FISA cannot continue to apply if the AUMF is to have its full effect; those constraints would “unduly 

interfere” with the operation of the AUMF. 

Contrary to the recent suggestion made by several law professors and former government officials, the 

ordinary presumption against implied repeals is overcome here. Cf. Letter to the Hon. Bill Frist, Majority Leader, 

U.S. Senate, from Professor Curtis A. Bradley et al. at 4 (Jan. 9, 2006). First, like other canons of statutory 

construction, the canon against implied repeals is simply a presumption that may be rebutted by other factors, 

including conflicting canons. Connecticut National Bank v. Germain, 503 U.S. 249, 253 (1992); see also 

Chickasaw Nation v. United States, 534 U.S. 84, 94 (2001); Circuit City Stores, Inc. v. Adams, 532 U.S. 105, 115 

(2001). Indeed, the Supreme Court has declined to apply the ordinary presumption against implied repeals where 

other canons apply and suggest the opposite result. See Montana v. Blackfeet Tribe of Indians, 471 U.S. 759, 765-66 

(1985). Moreover, Blackfeet suggests that where the presumption against implied repeals would conflict with other, 

more compelling interpretive imperatives, it simply does not apply at all. See 471 U.S. at 766. Here, in light of the 

constitutional avoidance canon, which imposes the overriding imperative to use the tools of statutory interpretation 

to avoid constitutional conflicts, the implied repeal canon either would not apply at all or would apply with 

significantly reduced force. Second, the AUMF was enacted during an acute national emergency, where the type of 

deliberation and detail normally required for application of the canon against implied repeals was neither practical 

nor warranted. As discussed above, in these circumstances, Congress cannot be expected to work through every 

potential implication of the U.S. Code and to define with particularity each of the traditional incidents of the use of 

force available to the President. 
37

particularly describing the place to be searched, and the persons or things to be seized.” U.S. 

Const. amend. IV. The touchstone for review of government action under the Fourth 

Amendment is whether the search is “reasonable.” See, e.g., Vernonia Sch. Dist. v. Acton, 515 

U.S. 646, 653 (1995). 

As noted above, see Part I, all of the federal courts of appeals to have addressed the issue 

have affirmed the President’s inherent constitutional authority to collect foreign intelligence 

without a warrant. See In re Sealed Case, 310 F.3d at 742. Properly understood, foreign 

intelligence collection in general, and the NSA activities in particular, fit within the “special 

needs” exception to the warrant requirement of the Fourth Amendment. Accordingly, the mere 

fact that no warrant is secured prior to the surveillance at issue in the NSA activities does not 

suffice to render the activities unreasonable. Instead, reasonableness in this context must be 

assessed under a general balancing approach, “‘by assessing, on the one hand, the degree to 

which it intrudes upon an individual’s privacy and, on the other, the degree to which it is needed 

for the promotion of legitimate governmental interests.’” United States v. Knights, 534 U.S. 112, 

118-19 (2001) (quoting Wyoming v. Houghton, 526 U.S. 295, 300 (1999)). The NSA activities 

are reasonable because the Government’s interest, defending the Nation from another foreign 

attack in time of armed conflict, outweighs the individual privacy interests at stake, and because 

they seek to intercept only international communications where one party is linked to al Qaeda or 

an affiliated terrorist organization. 

A. THE WARRANT REQUIREMENT OF THE FOURTH AMENDMENT DOES NOT 

APPLY TO THE NSA ACTIVITIES

In “the criminal context,” the Fourth Amendment reasonableness requirement “usually 

requires a showing of probable cause” and a warrant. Board of Educ. v. Earls, 536 U.S. 822, 828 

(2002). The requirement of a warrant supported by probable cause, however, is not universal. 

Rather, the Fourth Amendment’s “central requirement is one of reasonableness,” and the rules 

the Court has developed to implement that requirement “[s]ometimes . . . require warrants.” 

Illinois v. McArthur, 531 U.S. 326, 330 (2001); see also, e.g., Earls, 536 U.S. at 828 (noting that 

the probable cause standard “is peculiarly related to criminal investigations and may be unsuited 

to determining the reasonableness of administrative searches where the Government seeks to 

prevent the development of hazardous conditions”) (internal quotation marks omitted). 

In particular, the Supreme Court repeatedly has made clear that in situations involving 

“special needs” that go beyond a routine interest in law enforcement, the warrant requirement is 

inapplicable. See Vernonia, 515 U.S. at 653 (there are circumstances “‘when special needs, 

beyond the normal need for law enforcement, make the warrant and probable-cause requirement 

impracticable’”) (quoting Griffin v. Wisconsin, 483 U.S. 868, 873 (1987)); see also McArthur, 

531 U.S. at 330 (“When faced with special law enforcement needs, diminished expectations of 

privacy, minimal intrusions, or the like, the Court has found that certain general, or individual, 

circumstances may render a warrantless search or seizure reasonable.”). It is difficult to 

encapsulate in a nutshell all of the different circumstances the Court has found to qualify as 

“special needs” justifying warrantless searches. But one application in which the Court has 

found the warrant requirement inapplicable is in circumstances in which the Government faces 
38

an increased need to be able to react swiftly and flexibly, or when there are at stake interests in 

public safety beyond the interests in ordinary law enforcement. One important factor in 

establishing “special needs” is whether the Government is responding to an emergency that goes 

beyond the need for general crime control. See In re Sealed Case, 310 F.3d at 745-46. 

Thus, the Court has permitted warrantless searches of property of students in public 

schools, see New Jersey v. T.L.O., 469 U.S. 325, 340 (1985) (noting that warrant requirement 

would “unduly interfere with the maintenance of the swift and informal disciplinary procedures 

needed in the schools”), to screen athletes and students involved in extracurricular activities at 

public schools for drug use, see Vernonia, 515 U.S. at 654-55; Earls, 536 U.S. at 829-38, to 

conduct drug testing of railroad personnel involved in train accidents, see Skinner v. Railway 

Labor Executives’ Ass’n, 489 U.S. 602, 634 (1989), and to search probationers’ homes, see 

Griffin, 483 U.S. 868. Many special needs doctrine and related cases have upheld suspicionless 

searches or seizures. See, e.g., Illinois v. Lidster, 540 U.S. 419, 427 (2004) (implicitly relying on 

special needs doctrine to uphold use of automobile checkpoint to obtain information about recent 

hit-and-run accident); Earls, 536 U.S. at 829-38 (suspicionless drug testing of public school 

students involved in extracurricular activities); Michigan Dep’t of State Police v. Sitz, 496 U.S. 

444, 449-55 (1990) (road block to check all motorists for signs of drunken driving); United 

States v. Martinez-Fuerte, 428 U.S. 543 (1976) (road block near the border to check vehicles for 

illegal immigrants); cf. In re Sealed Case, 310 F.3d at 745-46 (noting that suspicionless searches 

and seizures in one sense are a greater encroachment on privacy than electronic surveillance 

under FISA because they are not based on any particular suspicion, but “[o]n the other hand, 

wiretapping is a good deal more intrusive than an automobile stop accompanied by 

questioning”). To fall within the “special needs” exception to the warrant requirement, the 

purpose of the search must be distinguishable from ordinary general crime control. See, e.g.,

Ferguson v. Charleston, 532 U.S. 67 (2001); City of Indianapolis v. Edmond, 531 U.S. 32, 41 

(2000). 

Foreign intelligence collection, especially in the midst of an armed conflict in which the 

adversary has already launched catastrophic attacks within the United States, fits squarely within 

the area of “special needs, beyond the normal need for law enforcement” where the Fourth 

Amendment’s touchstone of reasonableness can be satisfied without resort to a warrant. 

Vernonia, 515 U.S. at 653. The Executive Branch has long maintained that collecting foreign 

intelligence is far removed from the ordinary criminal law enforcement action to which the 

warrant requirement is particularly suited. See, e.g., Amending the Foreign Intelligence 

Surveillance Act: Hearings Before the House Permanent Select Comm. on Intelligence,103d 

Cong. 2d Sess. 62, 63 (1994) (statement of Deputy Attorney General Jamie S. Gorelick) (“[I]t is 

important to understand that the rules and methodology for criminal searches are inconsistent 

with the collection of foreign intelligence and would unduly frustrate the President in carrying 

out his foreign intelligence responsibilities. . . . [W]e believe that the warrant clause of the 

Fourth Amendment is inapplicable to such [foreign intelligence] searches.”); see also In re 

Sealed Case, 310 F.3d 745. The object of foreign intelligence collection is securing information 

necessary to protect the national security from the hostile designs of foreign powers like al 

Qaeda and affiliated terrorist organizations, including the possibility of another foreign attack on 

the United States. In foreign intelligence investigations, moreover, the targets of surveillance 
39

 

often are agents of foreign powers, including international terrorist groups, who may be specially 

trained in concealing their activities and whose activities may be particularly difficult to detect. 

The Executive requires a greater degree of flexibility in this field to respond with speed and 

absolute secrecy to the ever-changing array of foreign threats faced by the Nation.22

In particular, the NSA activities are undertaken to prevent further devastating attacks on 

our Nation, and they serve the highest government purpose through means other than traditional 

law enforcement.23 The NSA activities are designed to enable the Government to act quickly 

and flexibly (and with secrecy) to find agents of al Qaeda and its affiliates—an international 

terrorist group which has already demonstrated a capability to infiltrate American communities 

without being detected—in time to disrupt future terrorist attacks against the United States. As 

explained by the Foreign Intelligence Surveillance Court of Review, the nature of the 

“emergency” posed by al Qaeda “takes the matter out of the realm of ordinary crime control.” In 

re Sealed Case, 310 F.3d at 746. Thus, under the “special needs” doctrine, no warrant is 

required by the Fourth Amendment for the NSA activities. 

B. THE NSA ACTIVITIES ARE REASONABLE

As the Supreme Court has emphasized repeatedly, “[t]he touchstone of the Fourth 

Amendment is reasonableness, and the reasonableness of a search is determined by assessing, on 

the one hand, the degree to which it intrudes upon an individual’s privacy and, on the other, the 

degree to which it is needed for the promotion of legitimate governmental interests.” Knights,

534 U.S. at 118-19 (quotation marks omitted); see also Earls, 536 U.S. at 829. The Supreme 

Court has found a search reasonable when, under the totality of the circumstances, the 

importance of the governmental interests outweighs the nature and quality of the intrusion on the 

individual’s Fourth Amendment interests. See Knights, 534 U.S. at 118-22. Under the standard 

22 Even in the domestic context, the Supreme Court has recognized that there may be significant 

distinctions between wiretapping for ordinary law enforcement purposes and domestic national security surveillance. 

See United States v. United States District Court, 407 U.S. 297, 322 (1972) (“Keith”) (explaining that “the focus of 

domestic [security] surveillance may be less precise than that directed against more conventional types of crime” 

because often “the emphasis of domestic intelligence gathering is on the prevention of unlawful activity or the 

enhancement of the Government’s preparedness for some possible future crisis or emergency”); see also United 

States v. Duggan, 743 F.2d 59, 72 (2d Cir. 1984) (reading Keith to recognize that “the governmental interests 

presented in national security investigations differ substantially from those presented in traditional criminal 

investigations”). Although the Court in Keith held that the Fourth Amendment’s warrant requirement does apply to 

investigations of purely domestic threats to national security—such as domestic terrorism, it suggested that Congress 

consider establishing a lower standard for such warrants than that set forth in Title III. See id. at 322-23 (advising 

that “different standards” from those applied to traditional law enforcement “may be compatible with the Fourth 

Amendment if they are reasonable both in relation to the legitimate need of the Government for intelligence 

information and the protected rights of our citizens”). Keith’s emphasis on the need for flexibility applies with even 

greater force to surveillance directed at foreign threats to national security. See S. Rep. No. 95-701, at 16 (“Far 

more than in domestic security matters, foreign counterintelligence investigations are ‘long range’ and involve ‘the 

interrelation of various sources and types of information.’”) (quoting Keith, 407 U.S. at 322). And flexibility is 

particularly essential here, where the purpose of the NSA activities is to prevent another armed attack against the 

United States. 

23 This is not to say that traditional law enforcement has no role in protecting the Nation from attack. The 

NSA activities, however, are not directed at bringing criminals to justice but at detecting and preventing plots by a 

declared enemy of the United States to attack it again. 
40

balancing of interests analysis used for gauging reasonableness, the NSA activities are consistent 

with the Fourth Amendment. 

With respect to the individual privacy interests at stake, there can be no doubt that, as a 

general matter, interception of telephone communications implicates a significant privacy 

interest of the individual whose conversation is intercepted. The Supreme Court has made clear 

at least since Katz v. United States, 389 U.S. 347 (1967), that individuals have a substantial and 

constitutionally protected reasonable expectation of privacy that their telephone conversations 

will not be subject to governmental eavesdropping. Although the individual privacy interests at 

stake may be substantial, it is well recognized that a variety of governmental interests—including 

routine law enforcement and foreign-intelligence gathering—can overcome those interests. 

On the other side of the scale here, the Government’s interest in engaging in the NSA 

activities is the most compelling interest possible—securing the Nation from foreign attack in the 

midst of an armed conflict. One attack already has taken thousands of lives and placed the 

Nation in state of armed conflict. Defending the Nation from attack is perhaps the most 

important function of the federal Government—and one of the few express obligations of the 

federal Government enshrined in the Constitution. See U.S. Const. art. IV, § 4 (“The United 

States shall guarantee to every State in this Union a Republican Form of Government, and shall 

protect each of them against Invasion . . . .”) (emphasis added); The Prize Cases, 67 U.S. (2 

Black) 635, 668 (1863) (“If war be made by invasion of a foreign nation, the President is not 

only authorized but bound to resist force by force.”). As the Supreme Court has declared, “[i]t is 

‘obvious and unarguable’ that no governmental interest is more compelling than the security of 

the Nation.” Haig v. Agee, 453 U.S. 280, 307 (1981). 

The Government’s overwhelming interest in detecting and thwarting further al Qaeda 

attacks is easily sufficient to make reasonable the intrusion into privacy involved in intercepting 

one-end foreign communications where there is “a reasonable basis to conclude that one party to 

the communication is a member of al Qaeda, affiliated with al Qaeda, or a member of an 

organization affiliated with al Qaeda.” Press Briefing by Attorney General Alberto Gonzales and 

General Michael Hayden, Principal Deputy Director for National Intelligence, available at 

http://www.whitehouse.gov/news/releases/2005/12/20051219-1.html (Dec. 19, 2005) (statement 

of Attorney General Gonzales); cf. Edmond, 531 U.S. at 44 (noting that “the Fourth Amendment 

would almost certainly permit an appropriately tailored roadblock set up to thwart an imminent 

terrorist attack” because “[t]he exigencies created by th[at] scenario[] are far removed” from 

ordinary law enforcement). The United States has already suffered one attack that killed 

thousands, disrupted the Nation’s financial center for days, and successfully struck at the 

command and control center for the Nation’s military. And the President has stated that the NSA 

activities are “critical” to our national security. Press Conference of President Bush (Dec. 19, 

2005). To this day, finding al Qaeda sleeper agents in the United States remains one of the 

preeminent concerns of the war on terrorism. As the President has explained, “[t]he terrorists 

want to strike America again, and they hope to inflict even more damage than they did on 

September 11th.” Id. 
41

Of course, because the magnitude of the Government’s interest here depends in part upon 

the threat posed by al Qaeda, it might be possible for the weight that interest carries in the 

balance to change over time. It is thus significant for the reasonableness of the NSA activities 

that the President has established a system under which he authorizes the surveillance only for a 

limited period, typically for 45 days. This process of reauthorization ensures a periodic review 

to evaluate whether the threat from al Qaeda remains sufficiently strong that the Government’s 

interest in protecting the Nation and its citizens from foreign attack continues to outweigh the 

individual privacy interests at stake. 

Finally, as part of the balancing of interests to evaluate Fourth Amendment 

reasonableness, it is significant that the NSA activities are limited to intercepting international 

communications where there is a reasonable basis to conclude that one party to the 

communication is a member or agent of al Qaeda or an affiliated terrorist organization. This 

factor is relevant because the Supreme Court has indicated that in evaluating reasonableness, one 

should consider the “efficacy of [the] means for addressing the problem.” Vernonia, 515 U.S. at 

663; see also Earls, 536 U.S. at 834 (“Finally, this Court must consider the nature and 

immediacy of the government’s concerns and the efficacy of the Policy in meeting them.”). That 

consideration does not mean that reasonableness requires the “least intrusive” or most “narrowly 

tailored” means for obtaining information. To the contrary, the Supreme Court has repeatedly 

rejected such suggestions. See, e.g., Earls, 536 U.S. at 837 (“[T]his Court has repeatedly stated 

that reasonableness under the Fourth Amendment does not require employing the least intrusive 

means, because the logic of such elaborate less-restrictive-alternative arguments could raise 

insuperable barriers to the exercise of virtually all search-and-seizure powers.”) (internal 

quotation marks omitted); Vernonia, 515 U.S. at 663 (“We have repeatedly refused to declare 

that only the ‘least intrusive’ search practicable can be reasonable under the Fourth 

Amendment.”). Nevertheless, the Court has indicated that some consideration of the efficacy of 

the search being implemented—that is, some measure of fit between the search and the desired 

objective—is relevant to the reasonableness analysis. The NSA activities are targeted to 

intercept international communications of persons reasonably believed to be members or agents 

of al Qaeda or an affiliated terrorist organization, a limitation which further strongly supports the 

reasonableness of the searches. 

In sum, the NSA activities are consistent with the Fourth Amendment because the 

warrant requirement does not apply in these circumstances, which involve both “special needs” 

beyond the need for ordinary law enforcement and the inherent authority of the President to 

conduct warrantless electronic surveillance to obtain foreign intelligence to protect our Nation 

from foreign armed attack. The touchstone of the Fourth Amendment is reasonableness, and the 

NSA activities are certainly reasonable, particularly taking into account the nature of the threat 

the Nation faces. 

CONCLUSION

For the foregoing reasons, the President—in light of the broad authority to use military 

force in response to the attacks of September 11th and to prevent further catastrophic attack 

expressly conferred on the President by the Constitution and confirmed and supplemented by 
42

Congress in the AUMF—has legal authority to authorize the NSA to conduct the signals 

intelligence activities he has described. Those activities are authorized by the Constitution and 

by statute, and they violate neither FISA nor the Fourth Amendment.