The Evolution of Domestic Terrorism in the United States

Introduction
There has been growing concern about the threat of domestic terrorism, with extremists motivated by political, racial, ethnic, economic, health, and other grievances. In October 2020, the FBI arrested Adam Fox, Barry Croft, and several other accomplices in a plot to kidnap and potentially execute Michigan Governor Gretchen Whitmer. Members of this network, which had ties to militias in Michigan and other states, referred to Governor Whitmer as a “tyrant” and claimed that she had “uncontrolled power right now.”¹ They also discussed kidnapping Virginia Governor Ralph Northam, in part because of his lockdown orders to slow the spread of Covid-19.²

Some U.S. government agencies have outlined the threat from domestic extremists, though most have not provided recent data about terrorist incidents. In its Homeland Threat Assessment released in October 2020, the U.S. Department of Homeland Security concluded that “racially and ethnically motivated violent extremists—specifically white supremacist extremists (WSEs)—will remain the most persistent and lethal threat in the Homeland.”³ The report also assessed that anarchists and other individuals inspired by anti-government and anti-authority ideologies posed a threat. But it did not provide 2020 data. The Federal Bureau of Investigation similarly argued that the “top threat we face from domestic violent extremists” is from racially- and ethnically-motivated violent extremists, including white supremacists.⁴ Nevertheless, FBI officials have not publicly released their data, making it difficult for U.S. civilians to judge the degree and type of threat.

To help fill this gap, this analysis provides new data on the domestic terrorist threat in the United States. It asks several questions. What are the main trends in domestic terrorism in 2020 in such areas as terrorist motivation, tactics, and targets? How did 2020 compare to previous years? To answer these questions, the authors constructed a data set of terrorist attacks and plots in the United States from January 1, 2020 to August 31, 2020, which updated a broader CSIS data set of terrorist incidents in the United States from 1994 to 2020.⁵

Based on the data, this analysis has several findings, which are discussed at greater length later in this assessment. First, white supremacists and other like-minded extremists conducted 67 percent of terrorist plots and attacks in the United States in 2020. They used vehicles, explosives, and firearms as their predominant weapons and targeted demonstrators and other individuals because of their racial, ethnic, religious, or political makeup—such as African Americans, immigrants, Muslims, and Jews. Second, there was a rise in the number of anarchist, anti-fascist, and other like-minded attacks and plots in 2020 compared to previous years, which comprised 20 percent of terrorist incidents (an increase from 8 percent in 2019). These types of extremists used explosives and incendiaries in the majority of attacks, followed by firearms. They also targeted police, military, and government personnel and facilities. Third, far-left and far-right violence was deeply intertwined—creating a classic “security dilemma.”⁶ Since it is difficult to distinguish between offensive and defensive weapons, armed individuals from various sides reacted to each other during protests and riots, and each side’s efforts to protect itself and acquire weapons generally threatened others.

Despite these findings, this violence needs to be understood in historical context. The number of fatalities from terrorist attacks in the U.S. homeland is still relatively small compared to some periods in U.S. history, making it important not to overstate the threat.⁷ Roughly half of the years since 1994 had a greater number of fatalities from terrorism than 2020—at least between January 1 and August 31, 2020. There were also no mass-casualty terrorist attacks, a stark contrast from such incidents as the April 1995 Oklahoma City bombing, which killed 168 people; the September 2001 attacks, which killed nearly 3,000 people; and the June 2016 Orlando attack, which killed 49 people. Still, violence levels in the United States could rise over the next year depending on political polarization, the persistence of the Covid-19 pandemic (and reactions to policy decisions to mitigate its spread), worsening economic conditions, growing concerns about immigration (whether real or perceived), racial injustice, or other factors. It is also possible that the organizational structure of extremism could evolve from today’s decentralized landscape to include more hierarchically structured groups.

The rest of this report is divided into three sections. The first defines terrorism and differentiates this report’s focus on terrorism from other phenomena, such as hate crimes and riots. The second section outlines and analyzes the 2020 terrorism data. The third explores future developments, including the potential for violence after the 2020 presidential election.

1. The United States was defined as the 50 states, the District of Columbia, and Puerto Rico. From January to August 2020, terrorist attacks and plots were recorded in 25 states. No incidents were recorded in the District of Columbia or Puerto Rico.

2. Clionadh Raleigh, Andrew Linke, Håvard Hegre, and Joakim Karlsen, “Introducing ACLEDArmed Conflict Location and Event Data,” Journal of Peace Research 47, no. 5 (2010): 651–660, doi:10.1177/0022343310378914; “ADL H.E.A.T. Map,” ADL Center on Extremism, accessed September 25, 2020, https://www.adl.org/education-and-resources/resource-knowledge-base/adl-… and “Janes Terrorism and Insurgency Events,” Janes, accessed September 25, 2020, https://www.janes.com/military-threat-intelligence/terrorism-and-insurgency.

3. For more detail on the methodology and findings of the data set of events from January 1, 1994 to May 8, 2020, see Seth G. Jones, Catrina Doxsee, and Nicholas Harrington, “Methodology,” CSIS, June 17, 2020, https://csis-website-prod.s3.amazonaws.com/s3fs-public/publication/200616_Jones_Methodology_v3_0_0.pdf; and Seth G. Jones, Catrina Doxsee, and Nicholas Harrington, “The Escalating Terrorism Problem in the United States,” CSIS, CSIS Briefs, June 17, 2020, https://www.csis.org/analysis/escalating-terrorism-problem-united-states.

4. On definitions of terrorism, see, for example, Bruce Hoffman, Inside Terrorism, 2nd ed. (New York: Columbia University Press, 2006), 1–41, https://www.rand.org/pubs/commercial_books/CB386.html; and Global Terrorism Database, Codebook: Inclusion Criteria and Variables (College Park, MD: University of Maryland, October 2019), https://www.start.umd.edu/gtd/downloads/Codebook.pdf.

5. “Hate Crimes,” Federal Bureau of Investigation, accessed May 15, 2020, https://www.fbi.gov/investigate/civil-rights/hate-crimes.

6. See, for example, Grace Hauck, “Cars Have Hit Demonstrators 104 Times Since George Floyd Protests Began,” USA Today, September 27, 2020, https://www.usatoday.com/story/news/nation/2020/07/08/vehicleramming-att….

7. Far-right terrorists are often described as believing that social and racial inequality is inevitable, desirable, and natural. They also possess views that include anti-egalitarianism, nativism, and authoritarianism. See Jacob Aasland Ravndal et al., RTV Trend Report 2019: Right Wing Terrorism and Violence in Western Europe, 1990-2018 (Oslo, Norway: Center for Research on Extremism, 2019), 3, https://www.sv.uio.no/c-rex/english/topics/online-resources/rtv-dataset/…. Also see Jacob Aasland Ravndal and Tore Bjørgo, “Investigating Terrorism from the Extreme Right: A Review of Past and Present Research,” Perspectives on Terrorism 12, no. 6 (December 2018): 5–22, https://www.universiteitleiden.nl/binaries/content/assets/customsites/pe… Ehud Sprinzak, “Right-Wing Terrorism in a Comparative Perspective: the Case of Split Delegitimization,” Terrorism and Political Violence 7, no. 1 (1995): 17–43, doi:10.1080/09546559508427284; and Cas Mudde, “Right-Wing Extremism Analyzed: A Comparative Analysis of the Ideologies of Three Alleged Right-Wing Extremist Parties (NPD, NDP, CP’86),” European Journal of Political Research 27, no. 2 (1995): 203–224, doi:10.1111/j.1475-6765.1995.tb00636.x.