Small Wars Journal

Redefining Terrorism in the 21st Century

Fri, 10/22/2021 - 12:25am

Redefining Terrorism in the 21st Century

By CPT David M. Tillman

The history and evolution of terrorism is one of great complexity, spanning centuries rather than decades. Therefore, it should come as no surprise that “[t]     errorism remains a contested term, with no set definitions for the concept or broad agreement among academic experts on its usage” (Ward, 2018). However, many believe that recognizing terrorism is akin to Justice Potter Stewart’s concurring opinion regarding the recognition of obscenity in Jacobellis v. Ohio (1964) - “I’ll know it when I see it.” Although there is      a multitude of definitions, many experts[1]  agree that terrorism has two distinguishing elements – violence and a political dimension or motive (Burgess, 2015). This much can be discerned by the definitions of Bruce Hoffman and Louise Richardson of Georgetown University and Oxford University, respectively (Ward, 2018). However, by analyzing this phenomenon through the prism of the military’s Strategic Framework, we can reduce the elements of terrorism down to the ends, ways, and means (Eikmeier, 2007). [2] [CC3] 

Most modern definitions of terrorism only account for the ends and ways while completely neglecting the means. Fortunately, there are many different state and non-state agencies who have a vested interest in combatting terrorism, providing us with a bevy of more nuanced definitions, that when aggregated provide a holistic analytical framework. According to the Global Terrorism Database (2019), terrorism is a deliberate act of violence or threat thereof by a non-state actor, which includes two of the following three elements:

  1. Violence aimed at attaining political, economic, religious, or social goals


  1. Violence intended to coerce, intimidate, and/or communicate a narrative to a larger audience other than the immediate victims


  1. The act was outside the precepts of legitimate warfare activities


According to the U.S. Patriot Act (2001), Terrorism is defined as any crime committed with the use of ‘any weapon or dangerous device’, when the intent of the crime is determined to be the endangerment of public safety or substantial property damage rather than for ‘mere personal monetary gain.’ The U.S. Department of Justice (DOJ) and Department of Defense (DoD) have kept their definitions of terrorism generally in line with that of the U.S. Patriot Act (Hunter, Ginn, Storyllewellyn, & Rutland, 2020). Unfortunately, as this article will argue, a new definition of terrorism is required, as current ones (particularly federal laws) routinely fail to designate many egregious acts of violence as terrorism, when they categorically should be. To best illustrate the inadequacies of current definitions, this article will explore several examples of individuals, acts, or movements that should have been classified as terrorism, but never were.

On June 17, 2015, Dylan Roof entered Emanuel African Methodist Episcopal Church in Charleston, South Carolina and opened fire with a 0.45 caliber handgun, killing nine African American attendees. The subsequent investigation uncovered Roof’s personal website with his very own manifesto. As a result, the investigation concluded that the perpetrator’s actions were driven by an extremist ideology, fueled by racial hatred toward black people, and a devout belief that a race war was to ensue. Roof was found guilty of 33 charges, ranging from murder to hate crimes, and was sentenced to death by lethal injection on January 11, 2017. A retroactive analysis of the circumstances surrounding the attack, reveal that Dylan Roof’s crimes met all three elements outlined by the Global Terrorism Database, as well as those outlined by the U.S. Patriot Act, DoD, and DoJ (Hunter, Ginn, Storyllewellyn, & Rutland, 2020). [4] Despite meeting all the aforementioned criteria, neither the state nor the federal prosecutor levied a single charge of terrorism against Roof.

On October 27, 2018, Robert Gregory Bowers entered the Tree of Life Synagogue during the Shabbat morning armed with an AR-15 semi-automatic rifle and three Glock 0.357 SIG pistols which he used to fire upon the unarmed Jewish congregation. He killed eleven men and women and wounded six, which to date accounts for the deadliest attack on the Jewish Community on U.S. soil. The investigation revealed Bowers became radicalized by online white nationalist and Neo-Nazi propaganda that was primarily focused on promoting anti-Semitic conspiracy theories and hatred toward Jews. Survivors of the massacre recalled that during the onslaught, the shooter yelled “All Jews must die!” Bowers was indicted on 63 counts by a federal jury, some of which included homicide, aggravated assault, and hate crimes; qualifying him to receive the death penalty. As of October 2020, Bowers was seeking a plea deal (Dobuzinskis, 2019). Once again, a mass shooting that met all the requisite elements under the above definitions of terrorism, was instead labeled a hate crime. 

In recent years, the Involuntary Celibate (Incel) Movement has garnered increased attention by the public, following a slew of deadly attacks. Incel is a growing movement characterized by resentment, hatred, and violence directed toward women and society at large for creating a culture that facilitates the existence of Incels. This subculture has been interwoven with other extremist tendencies such as racism, anti-Semitism, and misogyny. The movement is fueled by the belief that all men are entitled to sex, but due to the current social culture, a small percentage of “alpha males” account for the vast majority of heterosexual sex. Although Incels view themselves as physically inferior, or “beta males,” they have supremacist inclinations whereby they presume to be intellectually superior to those around them and exclusively capable of truly understanding the dysfunctional societal hierarchy of Western culture (Ling, 2020). To date, in the U.S. and Canada alone, there have been 50 deaths attributed to Incels, most of which were targeted at women (Beckett, 2021). Based on the current definitions, nearly all violent attacks associated with the Incel Movement meet the three requisite elements of terrorism. 

These are not isolated incidents. The failure to define these violent crimes as terrorism is endemic, as demonstrated by a recent study published by the Behavioral Sciences of Terrorism and Political Aggression Journal. The authors concluded that of the 105 mass shootings that have occurred in the U.S. from 1982-2018, 43% met the requisite criteria to be classified as an act of terrorism. Some may argue that since the perpetrators of these egregious violent crimes typically receive harsh sentences, it seems trivial to insist that these attacks be reclassified. However, as they say in the counterterrorism community, we must get to the left of ‘boom.’ The goal of redefining terrorism is not to ensure that the judicial process generates adequately harsh punishments, but rather so that additional (and necessary) resources become available for detecting and preventing future attacks. Doing so will ensure greater resources are available to both the detection and prevention of these heinous acts, that if committed, will be prosecuted to the full extent of the law under federal terrorism charges. To facilitate this objective, I propose that terrorism be redefined as consisting of at least two of the three following      essential elements: 

  • Ends: Influencing targeted populations, institutions of power, judicial processes, and/or elected officials to advance a self-professed righteous cause centered upon religious, social, political, and/or economic ideologies.


  • Ways: An act or threat, with the intent to impose violence and/or destruction against infrastructure, civilian populations, community epicenters, government institutions, and/or systems of power, outside the principles of legitimate state-sanctioned warfare. 


  • Means: The intentional utilization of any objects, mechanisms, vehicles, resources (to include people), and/or facilities by any persons of generally sane mind to inflict violence, damage, and/or destruction upon the intended target.

Under this new framework, any act which presents at least two of the above elements (ends, ways, or means) would be considered terrorism. The reason only two of the elements are required, is that we inherently live in an imperfect world. The presumption that criminal investigations and intelligence collection will reliably reveal each of the above elements is overly optimistic.  It is important to keep in mind that absence of evidence is not evidence of absence.

To this day we remain unaware of the motive (or ends) that drove Stephen Paddock to fire over 1,000 rounds of ammunition from the 32nd story of the Mandalay Bay Hotel, on October 1, 2017, killing 60 and injuring 411. What we do know, is that upon reviewing the facts surrounding the Las Vegas Mass Shooting, this act undoubtedly met Justice Stewart’s standard for recognizing obscenity – we know it when we see it. Stephen Paddock committed an act of terrorism, regardless of whether the ends of this violent act are ever conclusively determined. The fight against counterterrorism will continue to become increasingly more complex over time. The failure to adapt our conceptual understanding of what constitutes as terrorism may yield devastating consequences to National Security. Ultimately, the purpose of this article is merely to initiate the necessary dialogue, as the counterterrorism community requires far more intricate discourse to work toward possible solutions. However, if there is one thing we know for sure, we must never rest in our pursuit of getting to the left of ‘boom’.





Beckett, L. (2021, March 03). The misogynist incel movement is spreading. should it be classified as a terror threat? Retrieved July 18, 2021, from

Burgess, M. (2015, February 13). A brief history of terrorism. Retrieved July 17, 2021, from

Crenshaw, M. (1981). The Causes of Terrorism. Comparative Politics, 13(4), 379. doi:10.2307/421717

Dobuzinskis, A. (2019, August 26). U.S. to seek death penalty for ACCUSED Pittsburgh synagogue shooter. Retrieved July 18, 2021, from

Global Terrorism Database. (2019). Retrieved February 18, 2020, from

Hunter, L. Y., Ginn, M. H., Storyllewellyn, S., & Rutland, J. (2020). Are mass shootings acts of terror? Applying key criteria in definitions of terrorism to mass shootings in the United States from 1982 to 2018. Behavioral Sciences of Terrorism and Political Aggression, 1-30. doi:10.1080/19434472.2020.1762108

Jacobellis v. Ohio (June 22, 1964) (Cornell Law School, Legal Information Institute, Dist. file).

Ling, J. (2020, June 02). Incels are radicalized and dangerous. but are they terrorists? Retrieved July 18, 2021, from


USA PATRIOT Act: Act of 2001 (HR 3162 – PL 107-56). (2001). Retrieved June 25, 2015, from


Ward, A. (2018, May 31). How Do You Define Terrorism. The National Interest. Retrieved July 14, 2021.


Categories: terrorism

About the Author(s)

CPT David Tillman served as the brigade information collection manager, 1st Brigade Combat Team “Bastogne,” 101st Airborne Division (Air Assault), Fort Campbell, KY. His other assignments include information collection platoon leader and brigade information collection manager, 3rd Armored Brigade Combat Team, 4th Infantry Division, Fort Carson, CO; and assistant S-2 and intelligence surveillance reconnaissance manager, 4th Squadron 10th Cavalry Regiment, 3rd Armored Brigade Combat Team, 4thInfantry Division. CPT Tillman’s military schools include the Defense Intelligence Agency (DIA) Collection Manager Basic Course; Signals Intelligence/Electronic Warfare Officer Course; DIA PACE Essential; DIA Joint Intermediate Targeting Course; Intelligence Surveillance Reconnaissance Manager Course; the Military Intelligence Basic Officer Leadership Course, and is currently a student at the Military Intelligence Captain Career Course. He has a bachelor’s of arts degree in criminal justice from Southern Illinois University (Carbondale), and he is currently a graduate student at the Northeastern University College of Professional Studies for a master’s of arts degree in strategic intelligence and analysis. CPT Tillman has completed one rotation at NTC, one rotation at the Joint Readiness Training Center, and one deployment in support of Operation Spartan Shield.



Mon, 10/25/2021 - 10:19am

How does this substantially change things?  Terrorism within the CONUS is considered criminal activity.  Recategorizing it as political act risks providing those awaiting trial with a platform to export their ideology.  


Mon, 10/25/2021 - 10:12am

In a practical sense, what does this change?  Inside the U.S., terrorism is treated as a criminal act.  Recategorizing "hate crimes" as "terrorism" may (or may not) make legal terminology cleaner, but at risk of providing some recognition that individual terrorists are now considered agents of political change, giving them a platform as a result.