The Challenges of Combatting Domestic Terrorism

CSPS Fellow Kimberly Talley discusses the challenges posed by domestic terrorism in the US.

Domestic terrorism poses a unique challenge to the US government. For the agencies and organizations tasked with protecting the homeland a bevy of issues accompany combatting domestic terrorism. We begin with the most basic: terminology.


There is no universally agreed upon definition of domestic terrorism. Variations in terminology – such as the interchanging use of domestic extremism and violent extremism with domestic terrorism – inhibit cooperation among federal, state and local levels of law enforcement. Authorities conflate ideology with action, obscuring the nature of threats. This lack of cohesive communication restricts the flow of intelligence between federal authorities and local counterparts, damaging the accuracy of threat assessments.

An FBI report issued in November 2020 defines domestic terrorism as “acts dangerous to human life that are a violation of the criminal laws of the United States or of any State; appearing to be intended to: intimidate or coerce a civilian population; influence the policy of government by intimidation or coercion; or affect the conduct of a government by mass destruction, assassination or kidnapping; and occurring primarily within the territorial jurisdiction of the United States.” This definition, formulated by FBI and DHS and commissioned by congressional law, has not yet become standard across all levels of government —an issue that continues to hamper interagency communication, particularly between state and federal authorities.  In fact, prior to this report, the federal government had no official definition of domestic terrorism. Inability to even define the problem highlights the government’s lackluster response to an urgent national security threat.

Legal Mechanisms and Civil Rights

Unanswered legal questions regarding civil liberties pose a unique obstacle in the fight against domestic terrorism: “Legal mechanisms available to some foreign partners, e.g., to ban DT [domestic terrorism] groups, are at odds with US civil liberties. Creating a DT designation in the United States could be perceived as government overreach and/or unconstitutional.” Some advocate for modeling the government’s response to domestic terrorism after its response to foreign terrorist threats; however, the US citizenship of many domestic bad actors restricts this course of action. Tactics used against foreign nationals are often not permissible against US citizens. US officials are confronted with a goldilocks conundrum, not knowing if they are doing too much or too little when monitoring US citizens. Challenges regarding travel surveillance illustrates this point – it is often difficult to discern whether a subject is travelling to exercise a Constitutional right, such as protesting, or if they intend to commit a crime. Another ambiguous arena is the limits of free speech, particularly online. It is difficult to distinguish constitutionally protected (yet potentially extremist) political discourse from mobilization-to-violence indicators. Too much surveillance or premature action by government officials threatens private citizen’s civil rights, yet the failure to halt a domestic terror incident despite an abundance of online discourse has devastating implications.

Even when extremism metastasizes into terrorism, detection is often difficult. In this era of online radicalization, most domestic terrorists are lone actors or based in small cells, not large well-known groups like al-Qaeda. The ODNI’s 2021 Unclassified Summary of Domestic Violent Extremism highlights the threat of lone offenders, noting “DVE [domestic violent extremist] lone offenders will continue to pose significant detection and disruption challenges because of their capacity for independent radicalization to violence, ability to mobilize discretely, and access to firearms.” As online resources become more widely available, new tactics will need to be developed to track, deter, and prevent the spread of domestic terror.


Since 9/11, the government has dedicated a tremendous number of resources to addressing foreign terrorist threats. DHS and the National Counterterrorism Center were created to prevent another attack on the homeland. With an initial 2004 budget of $39 billion to counter terrorism (among its many duties), the DHS budget has grown to $81 billion in 2021. The 2021 budget summary lists the phrase “domestic terrorism” once – in a 2019 accomplishments section. By comparison, “terrorism” is used 56 times throughout the 106-page document. Failure to recognize threats festering at home in our effort to stop another 9/11 is tragic. Nearly all terror attacks since 9/11 have been homegrown. The data is clear. Addressing this growing scourge calls for calibrating the government’s overall posture toward terrorism – we must commit more resources to combatting domestic terrorism.

Concluding Remarks

Domestic terrorism lives here. It most often rears its ugly head in times of high political polarity, permeating the public discourse. It is distinct from domestic extremism, yet closely interlinked – domestic extremism is not inherently violent or illegal, yet extremism can lead to terrorism. This presents unique challenges to US authorities seeking to protect the homeland from domestic terrorism. Identifying these (and additional) challenges is the crucial first step to combatting domestic terrorism.

Kimberly Talley is a first year full-time International Security M.A. student with two B.A. degrees in Political Science and Geography from Virginia Tech. Her research interests broadly include East Asian studies, Eastern European studies and studying international perception of US actions. Her future goals include pursuing a PhD in Political Science, teaching future generations, and/or working as a public servant for the US federal government.

Photo can be found here.