Violent Extremists, terrorists Targeting U.S. Critical Infrastructure

In their attempts to use violent force against civilian targets to achieve political aims, violent extremists of all backgrounds frequently choose critical infrastructure systems as targets. Simply defined, critical infrastructure comprises facilities and assets that are essential for the normal functioning of day-to-day life within a country. In the United States, a wide-reaching swath of sectors of the U.S. economy are considered critical infrastructure, from energy and transportation to agriculture and public health. The logic of terrorism targeting critical infrastructure is almost self-explanatory. Because the disruption of critical infrastructure sectors would, by the very nature of the targets in question, impede “business as usual” for large parts of American society and the U.S. government, extremists who seek to accomplish this aim tend to view critical infrastructure as an attractive target.(3)

Following this logic, violent extremists and terrorist organizations of numerous ideological persuasions have conducted devastating attacks on critical infrastructure in the United States. Notably, this type of attack plotting is not the sole purview of any single individual, group, or extremist movement. Regardless of ideological persuasion, terrorist attacks on critical infrastructure are ordered towards three different (but not mutually exclusive) goals. Some see targeting critical infrastructure as an efficient means of generating mass casualties during the commission of the attack. Large groups of individuals gather at particular types of facilities associated with critical infrastructure sectors and can be targeted en masse, and some attackers perceive certain kinds of critical infrastructure as less protected than others, making them easy targets. Others, understanding that a potent hit to a critical infrastructure facility can generate a wide-reaching societal disaster, target critical infrastructure to induce panic, fear, or terror in society as a pretext for gaining further support for their cause. Finally, some attackers believe that the aftermath of a successful attack on critical infrastructure will force the government to redirect national security and emergency response resources, creating a diversion that can free up space for further attack planning.(4)

Today’s terrorism threat picture in the U.S. is incredibly fluid, dynamic, and dangerous, and under this backdrop authorities are increasingly worried about an uptick in terrorist plotting against critical infrastructure. The two types of actors at the forefront of these types of planning are domestic violent extremists (DVE) and homegrown violent extremists (HVE), and the Department of Homeland Security warns that these actors increasingly “[view] attacks against U.S. critical infrastructure as a means to create chaos and advance ideological goals.”(5) Because of this renewed focus and concern, this paper reviews white supremacist DVE and Salafi-jihadist HVE attack planning against critical infrastructure during the past six years, ascertaining the current trends and differences in how these actors plan their attacks and their motivations for doing so.(6) Salafi-jihadists and white supremacists are far from the only extremist movements operating in the U.S. who have demonstrated an interest in conducting attacks on critical infrastructure.(7) However, the report evaluates these two movements because according to the Office of the Director of National Intelligence (ODNI) they were the most lethal HVE and DVE groups, respectively, during the period of the study.(8) After an evaluation of previous studies on the terrorist threat to critical infrastructure, the report analyzes 35 cases from a dataset of 94 individuals charged in federal court with planning violent extremist attacks between 2016 and 2022, highlighting key trends and the potential future developments of violent extremist attack plotting against critical infrastructure.


For the past twenty-five years, the protection of critical infrastructure from terrorist attacks has been a major homeland security priority across Presidential administrations. This correlates to waves of efforts by international and domestic terrorists to strike U.S. critical infrastructure sectors, with the goals of causing mass casualties through murder, societal chaos through mayhem, and/or obstruction of the U.S. counterterrorism mission through misdirection. Sadly, there are few signs in the American violent extremist landscape today that would suggest that reductions in vigilance or in efforts to improve the resiliency of critical assets are warranted. As new violent extremist movements, organizations, and threats come to the fore, the newest iterations of American HVE and DVE attack planners seem as interested as their predecessors in assaulting the systems and sectors that are necessary for the normal functioning of daily life in the U.S.

This report highlighted one of the reasons that American national security officials consider the current terrorism threat picture as one of the most combustible and deadly in decades, namely the continued efforts by American violent extremists of all stripes to attack critical infrastructure. Salafi-jihadist HVE and white supremacist DVE attack planners are placing critical infrastructure at the top of their respective target lists, with approximately one out of every two jihadist attack plotters and one out of three white supremacists arrested during the past six years considering attacks on infrastructure. In distinct ways, these groups have spread out their targeting across a growing range of the economic, political, and societal sectors that make up America’s critical assets, although each have developed special areas of focus. Perhaps the most specific of these threats came in the form of white supremacist attack plots against energy infrastructure, with 13 cases of individuals connected to white supremacist movements attempting to conduct attacks on power lines, the energy grid, and even a nuclear reactor site.

This anomaly in the data is not a coincidence, as for the past several years, white supremacist propaganda and its associated online ecosystem have both honed in on energy facilities, encouraging supporters of the movement to conduct attacks on energy supply, in the hopes that it will trigger a cataclysmic confrontation in American society and collapse the country from within. The rise of accelerationism, which is responsible for much of this paradigm shift within American white supremacist circles, is at play in examining many of the individuals’ alleged motivations for seeking to attack energy systems. There are two takeaways from this finding for American counterterrorism officials. First, from a protective standpoint, sector-specific efforts focused on energy infrastructure security and resilience against violent extremist attacks may be prudent. An increase in information sharing between the U.S. government and third-party ownership of energy facilities about violent extremist threats can aid greatly in this endeavor, as can intra-government collaboration between DHS/CISA, the Department of Energy, and federal law enforcement agencies.(112)

At a more strategic level, the rise in targeting of critical infrastructure inspired by accelerationist ideology should be broadly concerning, because at its core accelerationist doctrine is ideologically agnostic and has been an inspiration for a wider degree of domestic violent extremists beyond white supremacists. If accelerationism— or the view that violence should be ordered towards the collapse of American society— begins to influence other extremist milieus, a potential result is a growing number of plots targeting critical infrastructure as a way of achieving that goal. Already, there are concerns that far-left and anarchist groups in the U.S. are continuing their historical legacy of targeting infrastructure for attack and sabotage, albeit with a modern accelerationist twist.(113) For example, in 2018 the FBI arrested two self-proclaimed Ohio anarchists, Elizabeth Lecron and Vincent Armstrong, who were plotting several terrorist attacks on local targets of interest. One of these plots involved an attempt by the pair to construct an explosive device and bomb a local oil pipeline.(114)

Moving forward, more research is necessary to determine how the efforts of other violent extremists to target critical infrastructure—especially DVEs influenced by conspiracy theories like QAnon, militia violent extremists, single-issue violent extremists (especially pro- and anti-abortion violent extremists and animal rights groups), and anarchist/far-left violent extremists—compare to the movements examined in this report. In addition, as national security officials consider the possibility of cyber-attacks targeting critical infrastructure, mainly from actors associated with foreign governments, risk assessments of violent extremist threat actors in this arena could add to the overall threat picture and provide a point of comparison between violent extremists’ physical and virtual attacks on critical infrastructure.

1 U.S. Department of Homeland Security. “Critical Infrastructure Sectors.” Cybersecurity and Infrastructure Security Agency.

2 Vavra, Shannon. 2022. “DHS Warns That Right-Wing Extremists Could Attack Power Grid.” The Daily Beast, January 25, 2022.…

3 Ackerman, Gary, Praven Abhayaratne, J. Bale, Anjali Bhattacharjee, Charles Blair, Lydia Hansell, Andrew Jayne, et al. 2007. “Assessing Terrorist Motivations for Attacking Critical Infrastructure.” Livermore, California: Lawrence Livermore National Laboratory.

4 Ibid.

5 U.S. Department of Homeland Security. “Summary of Terrorism Threat to the U.S. Homeland.” National Terrorism Advisory Bulletin. February 7, 2022.…

6 The United States government refers to white supremacists as “racially and ethnically motivated violent extremists (REMVE) who are driven by a belief in the superiority of the white race.” “Annual Threat Assessment of the U.S. Intelligence Community.” 2021. Office of the Director of National Intelligence.….

7 Miller, “Terrorist Attacks Targeting Critical Infrastructure in the United States.”

8 “Domestic Violent Extremism Poses Heightened Threat in 2021.” 2021. U.S. Office of the Director of National Intelligence.; Wray, Christopher. 2022. “Statement Before the Senate Appropriations Committee, Subcommittee on Commerce, Justice, Science, and Related Agencies: Federal Bureau of Investigation Budget Request for Fiscal Year 2023.” Federal Bureau of Investigations.


112 “Critical Infrastructure Protection: CISA Should Improve Priority Setting, Stakeholder Involvement, and Threat Information Sharing.” 2022. Government Accountability Office. March 2022, GAO-22-104279.

113 Loadenthal, “Infrastructure, Sabotage, and Accelerationism.”

114 “Toledo Woman Sentenced for Planning Two Terrorist Attacks.” 2019. U.S. Department of Justice Press Release, November 20, 2019.…