The Terrorism Warning Lights Are Blinking Red Again

From his confirmation hearing to become director of Central Intelligence in May 1997 until September 11, 2001, George Tenet was sounding an alarm about Osama bin Laden and al Qaeda. In those four years before al Qaeda operatives attacked the World Trade Center and the Pentagon, Tenet testified publicly no fewer than ten times about the threat the group posed to U.S. interests at home and abroad. In February 1999, six months after the group bombed the U.S. embassies in Kenya and Tanzania, he claimed, “There is not the slightest doubt that Osama bin Laden . . . [is] planning further attacks against us.” In early 2000, he warned Congress again that bin Laden was “foremost among these terrorists, because of the immediacy and seriousness of the threat he poses” and because of his ability to strike “without additional warning.” Al Qaeda’s next attacks, Tenet said, could be “simultaneous” and “spectacular.” In private, Tenet was even more assertive. Breaking with standard protocols, he wrote personal letters to President Bill Clinton expressing his deep conviction about the gravity of the threat. And several times in 2001, he personally discussed his concerns about al Qaeda’s plans with President George W. Bush and National Security Adviser Condoleezza Rice. The CIA and the FBI may not have uncovered the time, place, or method of the 9/11 plot, but Tenet’s warnings were prophetic.

Two and a half decades later, Christopher Wray, the director of the FBI, is sounding similar alarms. His discussions within the Biden administration are private, but his testimony to Congress and other public statements could not be more explicit. Testifying in December to members of the Senate Intelligence Committee, Wray said, “When I sat here last year, I walked through how we were already in a heightened threat environment.” Yet after Hamas attacked Israel on October 7, “we’ve seen the threat from foreign terrorists rise to a whole nother level,” he added. In speaking about those threats, Wray has repeatedly drawn attention to security gaps at the United States’ southern border, where thousands of people each week enter the country undetected.

Wray is not the only senior official issuing warnings. Since he became commander of United States Central Command (CENTCOM) in 2022, General Erik Kurilla has been pointing out the worrying capabilities of the terrorist groups his forces are fighting in the Middle East and South Asia. These include al Qaeda, the Islamic State (also known as ISIS), and especially Islamic State Khorasan (ISIS-K), the ISIS affiliate that operates in Afghanistan and Pakistan. Christine Abizaid, the outgoing director of the National Counterterrorism Center, described “an elevated global threat environment” while speaking at a conference in Doha last month. And in testimony before the House Judiciary Committee just last week, U.S. Attorney General Merrick Garland, speaking about the possibility of a terrorist attack on the United States, said that the “threat level . . . has gone up enormously.”

Only with complete access to intelligence information could one form a fully independent view of the threat. But the FBI director’s and the CENTCOM commander’s statements almost certainly reflect the classified intelligence they are reading and the law enforcement and military operations in which their organizations are involved. Their words should be taken seriously. In the years since 9/11, other officials have warned about terrorist threats that, fortunately, did not materialize, but that does not mean Wray’s and Kurilla’s comments today should be discounted. The wax and wane of terrorism warnings over the years has generally corresponded with the level of actual risk. In many cases, too, those warnings triggered government responses that thwarted terrorists’ plans. Given the stakes, complacency is a greater risk than alarmism.

Combined, the stated intentions of terrorist groups, the growing capabilities they have demonstrated in recent successful and failed attacks around the world, and the fact that several serious plots in the United States have been foiled point to an uncomfortable but unavoidable conclusion. Put simply, the United States faces a serious threat of a terrorist attack in the months ahead. 

Fortunately, the United States has learned a great deal over the past 30 years about how to combat terrorist threats, including threats that are not yet well defined. President Joe Biden and his administration should now use that playbook. It includes steps the intelligence community should take to better understand the threat, steps to prevent terrorists from entering the United States, and steps to put pressure on terrorist organizations in the countries where they find sanctuary. One of the best models to follow is the set of measures Clinton authorized when the terror threat rose in the summer and fall of 1999. Those steps prevented a number of attacks, including at least one attack on the U.S. homeland. That success—as well as the United States’ failure to prevent 9/11—offers valuable lessons for modern policymakers. Today, as then, it is better to be proactive than reactive.

PIECES OF THE PUZZLE

Without access to classified intelligence, piecing together information from public congressional testimonies, successful terrorist attacks abroad, and foiled plots in the United States and elsewhere is the best way to build a picture of the threat. Clues about unsuccessful attempts in the United States in particular have come into view since the Biden administration persuaded Congress in April to extend Section 702 of the Foreign Intelligence Surveillance Act, the provision that allows the U.S. government to compel U.S. telecommunications and Internet providers to turn over the communications of foreigners outside the United States whose communications travel through the United States.

In at least eight appearances before Congress since last fall—including one just last week—Wray has identified three different categories of threats to the U.S. homeland: international terrorism, domestic terrorism, and state-sponsored terrorism. All three, he told the Senate Judiciary Committee in December, are “simultaneously elevated.”

Testifying before the House Intelligence Committee in March, he said that “the number one category” of terrorist threats in the United States included “lone actors or individuals operating in small cells using readily available weapons.” Noting the influence of Hamas’s October 7 terrorist attack, Wray has warned of “homegrown violent extremists” motivated by both Hamas’s attack and Israel’s response. He has said that the FBI is investigating many such individuals, but he has not provided further detail.

Assessing the threat from abroad, Wray told the Senate Homeland Security Committee last October that Washington cannot “discount the possibility that Hamas or another foreign terrorist organization may . . . conduct attacks here” in the United States. In April, he told the House Appropriations Committee that “the potential for a coordinated attack here in the homeland” was “increasingly concerning.”

The United States faces a serious threat of a terrorist attack in the months ahead.

Wray has focused on one country as a potential state sponsor of terrorism: Iran. In October, he told the Senate Homeland Security Committee that Tehran continues to plot against high-ranking “current or former” U.S. government officials as a means of exacting revenge for the United States’ assassination of senior Iranian military official Qasem Soleimani in January 2020. Although Iranian plans have failed so far, there is no guarantee that the next one will. The successful killing of a U.S. citizen, especially if it takes place on U.S. soil, would not only strike fear among the American public but also plunge Tehran and Washington into a crisis on a scale unseen since the Iranian regime took power in 1979.

The FBI director has also highlighted a specific security vulnerability. In December, Wray warned the Senate Judiciary Committee that foreign terrorists trying to get into the United States have the “ability to exploit any point of entry, including our southwest border.” In March, he drew the Senate Intelligence Committee’s attention to “a particular network [operating on the southern border].” He told the committee that this smuggling network has overseas facilitators with “ISIS ties that we are very concerned about.”

Kurilla has been sounding similar alarms from CENTCOM. The forces under his command conducted 475 ground operations and 45 airstrikes against ISIS targets in Iraq and Syria last year—killing or capturing almost 1,000 of the group’s fighters. In a March statement, Kurilla affirmed that both ISIS and al Qaeda “remain committed to inflicting violence.” Although U.S. forces have kept ISIS from controlling large portions of Iraq and Syria, by Kurilla’s count, the group still has at least 5,000 fighters. Over the span of just two weeks in early 2024, ISIS conducted 275 attacks—its highest rate in years. Al Qaeda, meanwhile, continues to operate from Afghanistan and Yemen.

Kurilla has called particular attention to ISIS-K, the ISIS affiliate in Afghanistan and Pakistan. In March 2023 testimony to the Senate Armed Services Committee, he warned that the group would be able to carry out an “operation against U.S. or Western interests abroad in under six months with little to no warning.” His words proved prescient earlier this year, when ISIS-K mounted the deadliest terror attack Iran had experienced since the founding of the Islamic Republic, in which two suicide bombers killed at least 95 people at a memorial on the anniversary of Soleimani’s death. ISIS-K struck again in March, when four terrorists killed 145 people and injured 550 more in a brazen attack on a concert hall in Moscow.

The commander of United States Africa Command (AFRICOM), General Michael Langley, has painted a similar picture. In testimony in March before the Senate Armed Services Committee, Langley noted that al Qaeda and ISIS are exploiting “underdeveloped, undergoverned areas” and that “recent military takeovers in West Africa are giving space to violent extremist organizations.” Langley told the committee that his forces conducted 18 attacks on those terrorist groups in 2023 as part of a larger campaign. His testimony is consistent with the assessment of most terrorism experts in and out of government that al Qaeda and ISIS groups in Africa are thriving.

Observable trends add weight to these officials’ concerns. Most important is the growing number of both successful and foiled attacks. According to the Global Terrorism Index, deaths from terrorism increased by 22 percent from 2022 to 2023. This year has already seen the two large ISIS-K attacks in Iran and Russia. And were it not for the outstanding work of German intelligence and police, the list of successful acts of terrorism in the past few months would have been longer. German authorities arrested foreign nationals who were allegedly planning attacks on the Cologne Cathedral late last year and the Swedish parliament building in Stockholm in March.

Foiled plots inside the United States should be the ultimate wake-up call. In April 2022, the Justice Department charged an Iranian government official based in Tehran with attempting to hire a hit man to assassinate former U.S. National Security Adviser John Bolton. The following month, the FBI reported that it had thwarted the plans of an Iraqi national living in Ohio to smuggle four people across the southern border to assassinate former President George W. Bush. Most recently, the FBI—as part of the Biden administration’s effort to convince Congress to reauthorize Section 702 of the Foreign Intelligence Surveillance Act—shared declassified intelligence with Politico showing that the agency had stopped a plot to attack critical infrastructure in the United States last fall. According to the FBI, the organizer inside the United States was in regular contact with a foreign terrorist group, had identified specific targets, and had made sufficient preparations to put the plan into motion.

A final piece of the puzzle is the string of recent statements by terrorist groups calling for attacks. Many pegged their threats to the events of October 7. Shortly after that day’s attack, al Qaeda issued a statement urging Muslims around the world to seize a “once in a lifetime” opportunity to commit acts of violence in support of Hamas’s cause. In January, al Qaeda in the Arabian Peninsula (AQAP) released videos calling for attacks on commercial flights worldwide and on targets in New York City. And in March, during the Muslim holy month of Ramadan, an ISIS-K spokesperson called on individuals to carry out lone-wolf attacks on Christians and Jews in the United States, Europe, and Israel. When terrorist groups make explicit threats to the United States, Washington should listen. It is not uncommon for adversaries to say precisely what they are going to do—as bin Laden did before 9/11.

THE LOGIC OF THE THREAT

Identifying terrorist threats involves identifying motive, means, and opportunity—the three key elements in any criminal investigation. In the case of terrorism, however, one more element is necessary: organizational capacity. If an individual or a group does not have the skills or connections to turn plans into action, they will not cross the threshold from a potential risk to an active one.

Motives abound for potential perpetrators of terrorist attacks. Two decades of war in Afghanistan and Iraq, as well as U.S. drone strikes in more than a dozen other countries, have generated resentment toward the United States that could drive individuals to seek violent retribution. More recently, Israel’s ongoing response to the horrific attacks on October 7 has killed at least 36,000 people (of which more than half are civilians) in Gaza. That operation will have what Director of National Intelligence Avril Haines has called a “generational impact on terrorism” and will create what Kurilla has described as “the conditions for malign actors to sow instability throughout the region and beyond.” The assassination of Soleimani in 2020, too, has prompted Iran to attempt attacks in the United States ever since. These efforts may accelerate as Iran faces a deepening conflict with Israel and instability at home following the death of its president. Even the threat of domestic extremism and lone-wolf attacks—the least predictable forms of terrorism—is likely to grow more serious as the United States approaches a polarized election between two candidates who regularly issue dire warnings that a victory by the other side would be the death knell of American democracy.

Next, consider means and opportunity. Airport security may have tightened significantly since 9/11, but weekly mass shootings prove that it remains relatively easy in the United States to buy high-powered assault weapons and enough ammunition to kill large numbers of people in a short period of time. Last year, hundreds of individuals on the United States’ terrorist watch list attempted to enter the country via the southern border. It is not difficult to imagine a person, or even a group, with the intent to do harm slipping across a border—where U.S. officials reported 2.5 million encounters with migrants in 2023—and then purchasing assault rifles and carrying out a large massacre. There is no shortage of locations across the United States where hundreds, if not thousands, of people gather on a regular basis—and all may be ready targets for those seeking to incite terror.

The final factor is organizational capacity. The United States’ “war on terror” has eliminated large numbers of fighters and planners. But as Kurilla warned earlier this year, ISIS and other groups still have the leadership, foot soldiers, and organizational structures necessary to orchestrate attacks. Wray, too, has urged lawmakers not to take too much comfort in terrorist groups’ shrinking sizes. As he said in December, “Let’s not forget that it didn’t take a big number of people on 9/11 to kill 3,000 people.”

PREVENTING THE UNTHINKABLE

The Biden administration already has a lot on its plate, between supporting Ukraine in its fight against Russia’s large-scale invasion, bracing for the possibility that Israel’s failing war against Hamas in Gaza will turn into a wider war against Iranian proxies in the region, and maintaining its focus on China. But policymakers should not underestimate the threat of a terrorist attack inside the United States. Assessments of national security threats must account for both the level of risk and the scale of potential consequences—and in the case of terrorism, both should compel the administration to take action.

Biden should launch a comprehensive campaign to halt any terrorist planning that may be underway, taking a page from the playbook Clinton adopted at the end of his second term. After listening carefully to the intelligence community’s warning about potential terrorist plots, Clinton resolved to take action. The attacks that were prevented at the turn of the century offer lessons today—as do the ones that weren’t prevented on 9/11.

When terrorist groups make explicit threats, Washington should listen.

In the fall of 1999, U.S. intelligence agencies collected information that strongly suggested bin Laden and al Qaeda were preparing to launch multiple attacks to coincide with the millennium. Although the adversary and the timing were clear, the targets and method of attack were not. This lack of detail did not stop Clinton from ordering a swift and sweeping response. As Tenet recounts in his memoir, what followed was a “frenzy of activity”: the CIA conducted operations in 53 countries against 38 targets, including the detention of dozens of suspected terrorists. The CIA engaged foreign partners, most notably working with Canadian authorities to break up an Algerian terror cell in Canada and helping Jordanian authorities arrest 16 terrorists planning an attack on tourists in Amman. As a result, no terrorist group successfully carried out an attack at the millennium. Among the more celebrated successes was the arrest of al Qaeda operative Ahmed Ressam, which thwarted the group’s plan to attack Los Angeles International Airport in December 1999. Immigration officers in Port Angeles, Washington, were on high alert because of the Clinton order, and they pulled Ressam aside at the U.S.-Canadian border crossing. In the trunk of his car, they discovered 100 pounds of high explosives and materials for multiple detonators. Ressam was later convicted on terrorism charges.

For Washington to mount a similar effort to counter today’s terror threat, the intelligence and security community must explain the danger to policymakers and the American public more consistently. Wray and Kurilla have been vocal about their concerns, but other officials have so far been more reserved. It is not clear whether this public reticence is merely a political calculation or an indication of disagreement. To clarify officials’ assessment of the threats, congressional intelligence committees should convene unclassified hearings with the directors of National Intelligence, the CIA, the FBI, and the National Counterterrorism Center and ask each agency to offer its candid views. Diagnosis must precede prescription. Policymakers need a clear picture of the threat before they can determine how to proceed and how to bring the American public on board.

Next, U.S. intelligence agencies should review all previously collected information related to terrorism. A reexamination of earlier reporting can yield new insights or even uncover information that was overlooked the first time. Tenet ordered a similar review in the summer of 2001. Although it did not stop 9/11, the exercise did reveal that the CIA had learned in 1999 that two al Qaeda members who later became hijackers possessed U.S. visas, but the CIA did not put them on the watch list at the time. When this information came to light, the two men were immediately put on the watch list, and the FBI began to search for them, albeit unsuccessfully. Similar clues could be out there today, and to find them, intelligence professionals will need to start doing what they call “shaking the trees.” One of the most effective measures they could take would be to ask the United States’ international counterterrorism partners to detain and interview—within their legal authority—individuals with ties to terrorism.

These steps to identify threats are critical, but action to prevent attacks is even more important. Given the particular vulnerability of the southern border, Biden’s recent executive order to restrict asylum processing is a valuable step toward limiting entry to the United States. But with U.S. Customs and Border Protection reporting close to 200,000 encounters with migrants at this border each month so far in 2024, and with thousands of people each week crossing the border undetected, the government will need to take additional action—including the use of national emergency authorities—to ensure that terrorists are not exploiting this overwhelmed channel to enter the country.

Action is also required to address threats before they come overseas. ISIS-K poses the most immediate threat, but it is based in Afghanistan, where the United States has not had a military presence since its withdrawal in 2021. Washington may therefore need to do something otherwise unthinkable: work with the Taliban. The group, which again rules Afghanistan after two decades of war with the United States, considers ISIS-K an adversary. The possibility of coordinating with the Taliban to target ISIS-K militants has been raised before, including by former Chairman of the Joint Chiefs of Staff Mark Milley in 2021. Washington does not need to provide weapons to the Taliban or put boots on the ground, but it should consider limited intelligence exchanges in which the United States offers information about possible ISIS-K targets inside Afghanistan in return for information from the Taliban about ISIS-K’s capabilities and plans for overseas attacks. The United States should likewise work with Pakistan, where ISIS-K also operates, to neutralize the group.

Taking these steps would be difficult in the best of times, let alone ahead of an election. But terrorists can strike without warning, and they feel no need to respect the U.S. political calendar. For the past two decades, under both Republican and Democratic administrations, the efforts of thousands of Americans in the military and intelligence communities have spared the country a second 9/11—or worse. This is an extraordinary achievement, but the work is not done. A terrorist attack is a preventable catastrophe. As the threat increases, policymakers must rise to the challenge to protect the U.S. homeland.