Our Ability to Fight Foreign Terrorism Just Got Weaker

By John Yoo

Tuesday, June 16, 2026

 

Beset by partisan scuffles for political advantage as the midterms approach, Congress on Friday night failed to renew one of the powers central to the fight against foreign terrorists. Without the power to intercept foreign electronic communications, Republican and Democratic leaders have allowed a large hole to emerge in Washington’s ability to detect and stop foreign attacks. Congress has demonstrated again that it cannot shoulder the government’s most fundamental duties; its failure now requires President Trump to draw on his constitutional power to fill the gap.

 

Until Friday night, Section 702 of the Foreign Intelligence Surveillance Act (FISA) allowed the National Security Agency and FBI to intercept electronic communications abroad. The intelligence agencies can use this information to build a mosaic of terrorist activities and inform law enforcement to pre-empt attacks before they occur. If our government had the legal ability to collect this information and share it before September 11, 2001, it could have prevented the catastrophic strikes on New York City and Washington, D.C.

 

As a Justice Department official on that day, and in the weeks and months after, I worked to plug that gap. We created the Terrorist Surveillance Program to intercept broad swaths of foreign communications to detect terrorist activities. But it had to operate without congressional authorization or judicial approval because, we believed, holding a public debate would tip off our enemies about our advantages and tactics. We knew that critics could challenge the program on Fourth Amendment grounds, because the interception of the messages occurred without a warrant. But we also concluded that foreigners had no constitutional rights against the U.S. government and that any U.S. communications unintentionally swept up would fall within the exigent circumstances exception to the Fourth Amendment. “The Fourth Amendment would almost certainly permit an appropriately tailored roadblock set up to thwart an imminent terrorist attack or to catch a dangerous criminal who is likely to flee by way of a particular route,” the Supreme Court observed in 2000.

 

When the existence of the program leaked, Congress eventually enacted Section 702 to place the surveillance program on a firm constitutional basis but included a sunset that required periodic re-authorization. Now that Congress has allowed Section 702 to lapse, President Trump will have to return to the constitutional basis that President Bush invoked at the outset of the war against al-Qaeda on September 11. FISA ultimately cannot limit the president’s powers to protect national security through surveillance because that authority stems from his unique Article II responsibilities. Intercepting enemy communications has long been part of waging war; indeed, it is critical to the successful use of force. The U.S. military cannot attack or defend to good effect unless it knows where to aim.

 

America has a long history of conducting intelligence operations to obtain information on the enemy. General Washington used spies extensively during the Revolutionary War. As president, he established a secret fund for spying that existed until the creation of the CIA. President Lincoln personally hired spies during the Civil War, a practice that the Supreme Court upheld. In both World Wars I and II, presidents ordered the interception of communications leaving the United States. Some of America’s greatest wartime intelligence successes have involved signals intelligence, as it is known. The most important was probably the breaking of Japanese diplomatic and naval codes during World War II, which allowed the U.S. Navy to anticipate the attack on Midway Island. Signals intelligence may be even more important in waging war against terrorists than nation-states. Al-Qaeda has launched a variety of efforts to attack the United States, and it intends to continue them. The primary way to stop those attacks is to find and stop al-Qaeda operatives who have infiltrated the United States. The best way to find them is to intercept their electronic communications about infiltrating the country.

 

The need for executive authority over electronic intelligence-gathering became apparent at the outset of the nation’s war against Islamist terrorist groups. In the hours and days after the September 11 attacks, members of the government thought that al-Qaeda might try to crash other airliners or use a weapon of mass destruction in a major East Coast city. Combat air patrols began flying above New York and Washington. Suppose a plane was hijacked and would not respond to air traffic controllers. In order to protect the nation from attack, it would be reasonable for U.S. anti-terrorism personnel to intercept any radio or cellphone calls to or from the airliner, in order to discover the hijackers’ intentions, what was happening on the plane, and whether it would be necessary for the fighters to shoot down the plane. Or suppose the government had to put up a net to intercept all cellphone calls in a city because it was searching for a terrorist cell that had yet to launch an attack. Under such circumstances, the absence of congressional authorization, or even limits imposed by Congress through FISA, should prevent the president from monitoring any radio or cellphone calls to or from the airliner; after all, the purpose is not to arrest and gather evidence for trial, but to protect the nation from attack. Indeed, because the United States is in a state of war, the military can intercept the communications of the plane to see if it poses a threat and target the enemy if necessary. This authority is not only within the president’s executive powers, but it also comports with the principle of reasonableness that guides the Fourth Amendment.

 

As commander in chief, the president has the constitutional power and the responsibility to wage war in response to a direct attack on the U.S. During the Civil War, President Lincoln undertook several actions — raising an army, withdrawing money from the treasury, launching a blockade — on his own authority in response to the Confederate attack on Fort Sumter, moves that Congress and the Supreme Court later approved. During World War II, the Supreme Court similarly recognized that once war began, the president’s authority as commander in chief and chief executive gave him the tools necessary to effectively wage war. In the wake of the September 11 attacks, Congress agreed that “the President has authority under the Constitution to take action to deter and prevent acts of international terrorism against the United States.”

 

Even legal scholars who argue against this historical practice concede that once the United States has been attacked, the president can respond immediately with force. The ability to collect intelligence is intrinsic to the use of military force. It is inconceivable that the Constitution would give the president the responsibility to protect the nation from attack but then disable him from gathering intelligence to use the military most effectively to defeat the enemy. Every piece of evidence of the Framers’ understanding of the Constitution suggests that the government would have the ability to meet a foreign danger. As James Madison wrote in Federalist No. 41, “security against foreign danger is one of the primitive objects of civil society.” Therefore, the “powers requisite for attaining it must be effectually confided to the federal councils.” After World War II, the Supreme Court declared in Johnson v. Eisentrager that “this grant of war power includes all that is necessary and proper for carrying these powers into execution.” Covert operations and electronic surveillance are clearly part of this authority.

 

During the writing of the Constitution, some Framers believed that the president alone should manage intelligence because only he could keep secrets. Several Supreme Court cases have recognized that the president’s role as commander in chief and the sole organ of the nation in its foreign relations must include the power to collect intelligence. These authorities agree that intelligence rests with the president because its structure allows it to act with unity, secrecy, and speed.

 

Presidents have long ordered electronic surveillance without any judicial or congressional participation. More than a year before the Pearl Harbor attacks, but with war clearly looming with the Axis powers, President Franklin Roosevelt authorized the FBI to intercept any communications, whether wholly inside the country or international, of persons “suspected of subversive activities against the Government of the United States, including suspected spies.” FDR was concerned that “fifth columns” could wreak havoc with the war effort. “It is too late to do anything about it after sabotage, assassinations and ‘fifth column’ activities are completed,” FDR wrote in his order. FDR ordered the surveillance even though a federal law at the time prohibited electronic surveillance without a warrant. Presidents continued to monitor the communications of national security threats on their own authority, even in peacetime. If presidents in times of peace could order surveillance of spies and terrorists, executive authority is only greater now, as hostilities continue against al-Qaeda. Justice Departments under Republican and Democratic presidents alike have held a similar view of the executive branch’s authority to conduct surveillance outside the FISA framework.

 

Courts have never opposed a president’s authority to engage in warrantless electronic surveillance of foreign individuals to protect national security. When the Supreme Court first considered this question in 1972, it held that the Fourth Amendment required a judicial warrant if a president wanted to conduct surveillance of a purely domestic group, but it refused to address surveillance of foreign threats to national security. In the years since, every federal appeals court, including the FISA Appeals Court, to address the question has “held that the President did have inherent authority to conduct warrantless searches to obtain foreign intelligence information.” In its 2002 decision in In Re: Sealed Case, which upheld the constitutionality of the Patriot Act’s main provisions, the FISA Appeals Court believed that the president’s power here was so obvious as not to merit much discussion, taking the president’s power to conduct surveillance during wartime “for granted,” and observing that “FISA could not encroach on the President’s constitutional power.”

 

Congress also implicitly authorized the president to carry out electronic surveillance to prevent further attacks on the United States. Congress’s September 18, 2001, Authorization to Use Military Force (AUMF) puts no limitation on time or place — only that the president pursue al-Qaeda. Although the president did not need, as a constitutional matter, Congress’s permission to pursue and attack al-Qaeda after the attacks, its passage shows that the president and Congress fully agreed that military action would be appropriate. Congress’s approval of the killing and capture of al-Qaeda members must obviously include the tools to locate them in the first place.

 

A choice between FISA and his constitutional authority gives the president the discretion to use the best method to protect the United States, whether through the military or by relying on law enforcement. There is a downside to relying on the president’s constitutional authority to wage war. It may mean that the fruits of warrantless surveillance will be used only to stop possible attacks but cannot be introduced into the criminal justice system. President Trump could alleviate any constitutional concerns about the expiration of Section 702 by publicly declaring that no evidence generated after its sunset will be used to prosecute criminal suspects. Although Section 702 cannot limit the president’s constitutional authority, it can provide a more stable system for the domestic collection of foreign intelligence, such as the NSA’s collection of phone call metadata and foreign e-mails, especially when used in prosecutions in federal court.

 

The real problem with operating under a Fourth Amendment framework is that it remains rooted in a law enforcement approach to surveillance. It ties the government’s counterterrorism efforts to individualized suspicion. Searches and wiretaps must target a specific individual already believed to be involved in harmful activity. But detecting terrorists who have no previous criminal record in the United States, and who are undeterred by the possibility of criminal sanctions, requires the use of more sweeping methods.

 

To successfully prevent attacks, the government must devote surveillance resources where there is a reasonable chance that terrorists will appear, or communicate, even if their specific identities remain unknown. What if the government knew that there was a 50 percent chance that terrorists would use a certain communications pipeline, such as e-mails provided by a popular Pakistani ISP, but that most of the communications on that channel would not be linked to terrorism? An approach based on individualized suspicion would prevent computers from searching through that channel for the keywords or names that might suggest terrorist communications, because there are no specific al-Qaeda suspects, and thus no probable cause. Rather than individualized suspicion, searching for terrorists depends on playing the probabilities, just as airport screenings do. The private owner of any website has detailed access to information about the individuals who visit the site that he can exploit for his own commercial purposes, such as selling lists of names to spammers, or gathering market data on individuals or groups. The government’s effort to find violent terrorists is a far more legitimate use of such data.

 

Individualized suspicion dictates the focus of law enforcement, but war demands that our armed forces defend the country with a broader perspective. Armies do not meet a “probable cause” requirement when they attack a position or fire on enemy troops or intercept enemy communications on a frequency. In the criminal justice system, the purpose is to hold a specific person responsible for a discrete crime that has already happened. It does not make sense when the purpose of intelligence is to take action, such as killing or capturing members of the enemy, to prevent future harm to the nation from a foreign threat.

 

This year is an anniversary not just for celebrating the 250th anniversary of the Declaration of Independence, but also for honoring those killed 25 years ago in the 9/11 attacks. This year should remind us not just of the idealism of the Founders, but also of the difficult choices that they (and we) faced in waging war. Properly understood, their other handiwork — the Constitution — should not be understood to subject the government to unreasonable burdens in carrying out its highest duty of protecting the nation from attack.