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Despite the recent attack in New Orleans, longer-term trends suggest that jihadist terrorism in the United States is not resurgent. The number of jihadist plots and attacks in the United States has been low since the territorial defeat of ISIS. The average lethality of jihadist terrorist attacks has also fallen since the peak of the caliphate. International groups such as the Islamic State and al Qaeda have filled more of an inspirational role rather than directly orchestrating attacks on the United States. Although formal links between attackers and plotters in the United States appear to be rare, this has not prevented individuals from carrying out lethal “lone wolf” attacks. Overall, jihadist terrorism in the United States does not merit additional resources at this time; however, international terrorism organizations continue to merit counterterrorism efforts.
In the early morning hours of New Year’s Day 2025, a U.S. citizen from Texas named Shamsud-Din Jabbar drove a truck into a crowd of people on Bourbon Street in New Orleans, killing 14 people.1 Jabbar was inspired by the Islamic State, making the incident the deadliest jihadist attack in the United States since the 2016 Pulse nightclub shooting in Orlando, Florida.2 To better understand attacks like Jabbar’s, CSIS compiled a dataset of 740 terrorist attacks and plots in the United States between January 1, 1994, and January 1, 2025, 140 of which were jihadist attacks and plots.3
Analysis of the jihadist attacks yields three main findings. First, the frequency of recorded jihadist attacks and plots against targets in the United States has been low since the territorial defeat of the Islamic State in 2019. Between the beginning of 2020 and New Year’s Day 2025, CSIS counted 8 jihadist attacks and 10 disrupted plots—an average of about 3 attacks or plots per year. Between 2013 and 2019, jihadists conducted 27 attacks, and 46 jihadist plots were disrupted—an average of about 10 attacks or plots per year.
Second, the lethality of jihadist terrorism in the United States has fallen since the territorial defeat of the Islamic State. This decline is likely the result of a decrease in the Islamic State’s ability to inspire violence rather than a loss of operational support from international terrorist organizations, as direct Islamic State support for attacks in the United States was lacking before 2019. U.S. terrorists have proved lethal even without support from international terrorists, with facilitated attacks accounting for only about 14 percent of deaths from jihadist violence in the last 20 years.
Third, international terrorist organizations have inspired, not directed, jihadist terrorism in the United States, though their potential to facilitate mass-casualty attacks makes them a serious threat. U.S. attacks facilitated by international terrorist groups have been no more lethal than those not facilitated by international groups since 9/11. But these groups have successfully facilitated mass-casualty attacks in Europe, and the United States has experienced several near misses since 9/11.
Taken together, these findings suggest that jihadist terrorism in the United States does not merit additional special attention from policymakers or law enforcement beyond the high levels it already receives, but international jihadist organizations do merit continued counterterrorism efforts.
This analysis focuses on terrorism, defined here as the deliberate use or threat of premeditated violence by nonstate actors with the intent to achieve political goals by creating a broad psychological impact of fear or intimidation.4 For inclusion in the dataset, events had to meet all parts of this definition.
This brief examines the threat posed by jihadist terrorism, specifically terrorism motivated by variations on the Salafi-jihadist ideology espoused by the Islamic State and al Qaeda. Salafi-jihadists seek to violently revive a version of Islam they believe was practiced in the early years of the religion.5 They believe they have a religious obligation to participate in violence in what they see as a defense of Islam, and they exhibit an extremely expansive understanding of who constitutes a valid target.6 Many also reject democracy or even the modern state system as un-Islamic, favoring its replacement with a regional or global Islamic state.7 U.S. jihadists vary in their theological knowledge, and many have only minimal understanding of the ideological tradition they claim to follow.8 For this study, when an attacker expressed solidarity or sympathy for at least one jihadist group or the global Salafi-jihadist movement, the authors coded the incident as an act of jihadist terrorism.
Using this definition, CSIS compiled and analyzed a dataset of terrorist attacks and plots in the United States. The dataset includes information such as incident date, location, target and location type, weapon used, and fatalities, as well as the perpetrator’s age, sex, ideology, group affiliation, and current or former affiliation with the military or law enforcement. For the purposes of this brief, four new variables were added: direct contact with an international terrorist organization, type of support given by the international terrorist organization, foreign fighter status, and whether the assailant acted alone or with a group. The full methodology and a codebook for the dataset, excluding the four new variables, are linked at the end of this brief.
Between the beginning of 1994 and the beginning of 2025, jihadists conducted or plotted 140 reported attacks in the United States. This type of attack has undergone two main spikes since 9/11. The first occurred in the early years of Barack Obama’s presidency, and the second between the declaration of the Islamic State’s caliphate in 2014 and the fall of its last territorial holding in 2019 (Figure 1). Most jihadist attacks and plots have targeted civilians, though both these periods of increased jihadist activity saw significant numbers of attacks and plots against military, government, and law enforcement targets.
Jihadist ideology enables broad civilian targeting. Salafi-jihadist thinkers have steadily eroded the protected status of civilians, at times arguing that non-Muslim civilians are valid targets, that even Muslim civilians may be killed as acceptable collateral damage, and that non-Muslim civilians who have “assisted [the perceived enemies of Islam] in combat, whether in deed, word, mind, or any other form of assistance” may be targeted.9 Some Salafi-jihadists also practice an expansive form of excommunication known as takfir, which they believe gives them theological license to liberally target Muslim civilians whom they deem insufficiently observant.10
Two noticeable spikes in military targets occurred in 2010 and 2015, with six attacks and plots targeting the military in 2010 and seven in 2015. The spike in 2010 is attributable to a single actor, Yonathan Melaku, who was responsible for five of the six attacks and plots in 2010. Over the course of 17 days, he opened fire on several military installations in northern Virginia, including the Pentagon, a U.S. Coast Guard recruiting office, and the National Museum of the Marine Corps. No fatalities occurred, but there was over $100,000 worth of damage.11 In 2015, the Islamic State in Iraq and Syria (ISIS) published a list of 100 U.S. service members, including their names, photos, and home addresses, encouraging its “brothers residing in America” to kill those on the list.12 This list was directly linked to at least one jihadist plot against the military in 2015 and could have affected other plotters and attackers in their choice of a military target.13
U.S. citizens have perpetrated most of the jihadist violence in the United States. Since 9/11, the majority of U.S. jihadists (80 percent) have been citizens or residents of the United States, and more than 40 percent are natural-born U.S. citizens.14 Although the vast majority are men, the image of the young hothead is somewhat misplaced: the average jihadist is in his late 20s.15 Foreign nationals have conducted or attempted some notable attacks. Aside from the 9/11 attacks, among the most notable are the attempt by al Qaeda in the Arabian Peninsula (AQAP) to bomb Northwest Airlines Flight 253, which could have killed 289 people (excluding the bomber) had the explosives successfully detonated, and the Naval Air Station Pensacola shooting, in which a Royal Saudi Air Force officer killed three people with AQAP support.16
As the Bourbon Street attack suggests, the jihadist movement in the United States is resilient. However, the data so far do not indicate that it is resurgent comparable with its past peaks. The number of jihadist attacks and disrupted plots against the United States decreased after the territorial defeat of the Islamic State in 2019 and has stayed much lower than at the peak of its territorial control (Figure 2).17 Although jihadist attacks or plots made up nearly a quarter of all recorded terrorist attacks or plots in the United States in 2024, this seeming increase is more the result of a decrease in the total number of terrorist plots recorded in the United States than a surge in jihadist activity. The average number of recorded attacks and plots was 38 for each year between 2020 and 2023, while the first 11 months of 2024 recorded only 21 such plots and attacks.
The decline in jihadist attacks in the United States is a complex phenomenon resulting from a variety of factors, some of which are out of policymakers’ control. Perhaps most important is that current events seem to mobilize jihadists to conduct attacks. No recent geopolitical event has inspired jihadist attacks and plots in the United States comparable with previous catalysts such as the 2014 declaration of an Islamic state.18 Although the Taliban’s victory in Afghanistan and Israel’s war in Gaza had the potential to mobilize jihadist sympathizers in the United States, a surge in recorded attacks and plots has not yet materialized. Neither has the ascendance of al Qaeda and Islamic State affiliates in Africa inspired U.S. jihadists in the way that ISIS did.19
Military pressure on the Islamic State has likely deprived would-be jihadist terrorists in the United States of an important source of support for their attacks. The Islamic State adopted an approach frequently called the “virtual facilitator” model, in which terrorist operatives in Islamic State–controlled areas plotted attacks with and provided advice to individuals or groups in a target country like the United States, pushed them to adopt more extreme views, or integrated them into jihadist networks.20 The frequency of this approach appears to have waned since the Islamic State lost its last major territory in the Middle East. Between 2013 and 2019, there were 13 jihadist attacks or plots involving virtual contact with a member of a terrorist organization located outside the United States, but since the fall of the Islamic State, only three have involved such contact.21
The reduction in facilitated attacks may be credited, at least in part, to U.S. counterterrorist pressure. Although virtual facilitators do not require control over territory the way terrorist trainers of the past have, facilitation still requires skills like ideological persuasion or bomb-making training—skills that diminish within terrorist organizations when operatives are killed or captured.22 Virtual facilitation also requires connecting to the internet, which exposes operatives to risk of detection and therefore capture or death.23 International pressure on the Islamic State has seemingly reduced its overall capability to conduct attacks—which has also manifested as a decline in attacks in the Middle East—and has forced its operatives to limit virtual facilitation to avoid targeting.24
Another factor likely limiting the number of attacks is the low rate of radicalization of the U.S. Muslim community and its regular cooperation with law enforcement. Many of the plots the FBI has disrupted have been discovered after Muslim community members alerted law enforcement to suspicious activity.25 Even the terrorist who carried out the worst post-9/11 jihadist attack in the United States, the Pulse nightclub attack, was the subject of an FBI investigation prompted years earlier by Muslim community vigilance and concern.26
Finally, the U.S. domestic counterterrorist enterprise has expanded dramatically in the past 20 years, which has likely reduced terrorist plotting. Although the United States does not appear to be disrupting a greater percentage of jihadist plots today than it did during the Islamic State’s heyday, it may be deterring more terrorists than it did before the surge in resources it received after 9/11, incentivizing terrorists to forego plotting that they would have otherwise conducted due to fear of exposure.27
Despite the large number of deaths caused by the Bourbon Street attack, the data from the last several years show that U.S. jihadists are not growing more lethal on average. Instead, their attacks appear to have grown less lethal since the peak of the caliphate. Between 2013 and 2017, jihadists attackers in the United States killed on average at a higher annual death-per-attack rate (about 3) as compared with the average annual death-per-attack rate since 2017 (about 0.4), though the New Orleans attack may affect this trend, depending on what else transpires in 2025.
Jihadist’s relative lethality as compared with all other domestic terrorist attacks has also decreased since the defeat of ISIS. Jihadist attackers consistently accounted for a higher proportion of fatalities than their respective proportion of attacks during the heyday of the Islamic State (Figure 3). But since 2018, jihadist attackers accounted for an equal or lower proportion of fatalities than their relative proportion of attacks. Whether this trend will continue in 2025 remains to be seen.
The Islamic State’s ability to inspire people abroad likely played a major role in jihadists sustaining high levels of lethality from 2013 to 2017. The abstract goals of jihadist groups, including punishing their enemies, make jihadists more interested in highly symbolic mass-casualty attacks.28 Jihadists often see violence as an end in itself, as opposed to terrorists who use violence primarily as a means to an end. The Islamic State was both especially violent and especially abstract, given one of the group’s apparent goals of bringing about a religious apocalypse and its general call to strike at its many enemies.29 Jihadists following the Islamic State’s example between 2013 and 2019 therefore had ideological reasons to pursue highly lethal attacks against numerous targets.
Virtual facilitation by international jihadist organizations has not made U.S. jihadists more effective, though it seems intuitive that connections with organized terrorist groups would make attackers more dangerous. In the past 20 years, only four attacks have been carried out by a jihadist assailant who had direct contact with an international terrorist organization. These attacks killed an average of five people, whereas jihadist attackers who did not have direct contact with an international terrorist organization killed an average of seven people per attack (the Pulse nightclub attack, which killed 49 people, accounts for much of this discrepancy).
Terrorists in the United States are perfectly capable of conducting highly lethal attacks without support from international terrorist groups. U.S. intelligence did not find the perpetrator of the Pulse Nightclub shooting had contact with any members of an international jihadist organization.30 The 2015 shooting in San Bernardino, California, killed 14 people, but the shooters were not part of a cell or network.31 The shooter at Fort Hood in 2009 had contact with AQAP member Anwar al-Awlaki, though investigators believe the shooter acted alone and required no tactical or material support. He conducted the shooting in an area he had access to and used a gun he purchased legally.32
The lack of an association between jihadist lethality and support from a terrorist organization likely also results from law enforcement and counterterrorism efforts. Details of plots supported by international terrorist organizations but disrupted by law enforcement suggest that they could have been far more lethal. In the past 20 years, only 4 of 23 (17 percent) jihadist plots involving direct contact with a foreign terrorist organization resulted in attacks, compared with 43 of 106 (40 percent) that did not involve such contact. Contact with known terrorists is likely to increase the risk that plotters in the United States will be detected.
Nonetheless, links with international Salafi-jihadist groups could increase U.S. terrorists’ lethality. In Europe, the most lethal jihadist plots have frequently surpassed their U.S. counterparts in terms of lethality and have involved significant links to foreign terrorists (Table 1). The 2004 Madrid bombings, the 2015 Bataclan theater attacks in Paris, the 2005 UK public transit bombings, and the 2016 Brussels attacks all used more sophisticated explosives than any jihadist attack in the United States, and they all had direct links to al Qaeda or Islamic State operatives overseas.
There may also have been occasions when the United States was simply lucky to avoid more lethal internationally facilitated attacks. U.S. counterterrorist authorities failed to detect and disrupt a 2010 plot to set off a car bomb in Times Square until a T-shirt vendor happened to spot the vehicle and call the police.33 Despite the attacker having trained with Tehreek-e-Taliban Pakistan bomb makers in Pakistan, he produced a bomb investigators described as “amateurish” that failed to explode.34 Had he been more competent, the bombing could have produced a large number of casualties.
Most U.S. jihadist plots involve no direct link with international terrorist organizations. Only 23 of the 129 (about 18 percent) attacks and plots recorded in the past 20 years involved known contact between plotters and a member of an international terrorist organization. Of these plots and attacks, 11 involved al Qaeda affiliates and nine involved Islamic State affiliates, with most of the Islamic State plots and attacks occurring while the group still held significant territory in the Middle East (Figure 4).
Al Qaeda and its affiliates have frequently provided plotters and attackers with training in a more traditional mode, whether it be bomb-making training or flight training for hijacking airplanes. For example, in 2019, al Shabaab trained Cholo Abdi Abdullah for months in Somalia, and he spent time at a flight school to prepare for hijacking a commercial aircraft for a “9/11-style attack.”35
However, not all contact with al Qaeda or its affiliates results in the provision of support. Nidal Hasan, the Fort Hood shooter, had email contact with al-Alwaki, but there is little evidence that AQAP provided support to Hasan.36 Nonetheless, al-Alwaki has had quite an impact on U.S. jihadi plots and attacks: About a quarter of U.S. jihadist cases since 2007 explicitly mention al-Awlaki pertaining to his influence or contact with individuals.37
Unlike al Qaeda and its affiliates, the Islamic State contacted and supported almost all of its assailants virtually rather than by training them abroad. A foiled 2024 plot to conduct an attack on Election Day in Oklahoma City is the most recent of these plots. The Department of Justice has accused the alleged plotter of making contact online with a member of the Islamic State, probably the Islamic State–Khorasan Province (ISKP).38
Some U.S. jihadists have also benefitted from the expertise of foreign jihadist organizations without direct contact. The Boston Marathon bombers, for example, claimed to have learned to construct explosives from AQAP’s online magazine Inspire.39 The extent to which instructions broadcast by international terrorist organizations as part of their propaganda efforts have contributed to U.S. terrorism is extremely difficult to discern due to the complexity of radicalization and lack of high-quality data.
First, jihadists do not merit additional special attention from domestic law enforcement or policymakers beyond the already high levels they currently receive. Despite the lethality of the Bourbon Street attack, there is no evidence that it is part of a jihadist resurgence in the United States.
Second, current U.S. approaches to surveilling and disrupting overseas terrorists merit continued support from policymakers. Given the record of deadly attacks in Europe and the near misses in the United States, plots enabled by foreign terrorists remain a threat worth sustained attention. The current U.S. approach to monitoring foreign terrorists has repeatedly justified its continuation in the next administration. U.S. authorities seem to disrupt plots at a higher rate when plotters are in contact with foreign terrorists, and the United States has warned a variety of governments of ISKP plots targeting their citizens despite the lack of an official presence in Afghanistan.40
Alexander Palmer is a fellow in the Warfare, Irregular Threats, and Terrorism Program at CSIS. Skyeler Jackson is an intern with the Warfare, Irregular Threats, and Terrorism Program at CSIS. Daniel Byman is a senior fellow with the Warfare, Irregular Threats, and Terrorism Program at CSIS.
View the methodology for this brief here.
This brief is made possible by general support to CSIS. No direct sponsorship contributed to this report.
Please consult the PDF for references.
