Definition of Terrorism

Monterey Terrorism & Research Education Program



Jeffrey M. Bale

In order to clarify the focus of MonTREP’s research, it may be worthwhile to make a few preliminary remarks about terrorism and the general categories of terrorist groups. Perhaps the first desideratum should be to draw a clear analytical distinction between “terrorism” in the strict sense of the term and other types of non-state violence, a distinction that unfortunately needs to be made at the outset precisely because most definitions of terrorism – including those employed by many government agencies


– are imprecise if not seriously misleading. Perhaps the best way to distinguish between terrorism and other forms of violence is to recognize that most acts of violence are dyadic, i.e., they involve only two parties or protagonists, the perpetrator(s) and the victim(s):

Perpetrator(s) Victim(s)

In marked contrast, bona fide acts of terrorism are triadic, i.e., they involve three parties or protagonists, the perpetrator(s), the victim(s), and a wider target audience (or audiences):

Perpetrator(s) Victim(s) Wider Target Audience(s)

In short, terrorism is violence that is consciously carried out by the perpetrator(s) primarily in order to influence the attitudes and behavior of a wider target audience (or multiple target audiences).


It is, as Brian Jenkins and others have aptly pointed out, violence for psychological effect.


One of the many perverse ironies of terrorism is that, although only the actual victims suffer its effects in the most direct and brutal manner, their importance is strictly secondary and derives principally from the fact that they have been specifically selected because they are viewed as symbolizing something larger or representing a broader category of persons. To put it another way, the most important nexus in any terrorist act is between the perpetrators and the target audience(s) they are trying to influence, and in that sense the actual victims are merely an instrument used by the perpetrators to send messages to those wider audiences. It follows from this that targeted assassinations of particular individuals (e.g., murders of particularly effective or brutal policemen) or attacks that are solely designed to kill large numbers of people (e.g., massacres) are not, strictly speaking, acts of terrorism. They would only constitute acts of terrorism if their primary purpose was to traumatize and influence the behavior of wider target audiences, i.e., people other than the actual victims. In many real-world cases, of course, attacks are carried out for both physically destructive and such psychologically manipulative reasons, but the latter would have to predominate in the eyes of the perpetrators if such attacks are to be regarded as terrorism per se. Hence violent acts that inadvertently end up traumatizing people other than the actual victim, e.g., a series of rapes in a particular neighborhood, should not be characterized as acts of terrorism.

Thus terrorism is nothing more than a violent tactic or technique of psychological manipulation, and like other techniques it can be used by anyone, whatever their ideological orientation or relationship to the state. It can be employed on behalf of state power or in opposition to state power, by left-wingers, right-wingers, or centrists, by the irreligious or the religious, and for an infinite variety of causes. One man’s terrorist is therefore not another man’s freedom fighter, as many claim; rather, one man’s terrorist should invariably also be another man’s terrorist, since regardless of the underlying cause involved – or whether one sympathizes with or deplores it – a terrorist can be identified purely by the methods he or she chooses to employ. It follows that only those organized groups that rely primarily on terrorist techniques can legitimately be described as terrorist groups.

However, it should be emphasized that MonTREP carries out research on both violence by non-state actors and on unconventional state-sponsored violence, even when these do not technically fall into the category of terrorism in this carefully delimited sense.

The Main Categories of Non-State Terrorist Groups

Now that the meaning of the term “terrorism” has been clarified, the principal ideological categories of non-state terrorists in recent decades need to be identified. There are four primary types of sub-national terrorist groups that have had historical significance during and after the Cold War:

  1. ethno-nationalist separatist and irredentist groups – groups relying heavily on terrorism that seek either to establish an independent state for the ethnic, linguistic, cultural, or national community with which they are affiliated, or (especially if they already have their own independent state) to unite all of the members of their community – including those that live in neighboring countries – under the aegis of such a state. Some of the most important groups in this category have been the Armenian Secret Army for the Liberation of Armenia (ASALA), Euskadi ta Askatasuna (ETA: Basque Fatherland and Freedom), the Front de Libération Nationale de la Corse (FLNC: National Liberation Front of Corsica), the Irish Republican Army (IRA), the Palestine Liberation Organization (PLO), the Partiya Karkarên Kurdistanê (PKK: Kurdistan Worker’s Party), the Liberation Tigers of Tamil Eelam (LTTE, also known as the Tamil Tigers), and Sikh groups seeking to create an independent state of “Khalistan.”
  2. secular left-wing groups – groups relying heavily on terrorism that seek to overthrow the capitalist system and either establish a “dictatorship of the proletariat” (Marxist-Leninists) or, much more rarely, a decentralized, non-hierarchical sociopolitical system (anarchists). Some of the most important groups in this category have been the Fuerzas Armadas Revolucionarias de Columbia (FARC: Revolutionary Armed Forces of Columbia), Sendero Luminoso (SL: Shining Path) in Peru, various Maoist groups in Nepal, and the so-called “fighting communist organizations” in Europe, such as Action Directe (AD: Direct Action) in France, the Brigate Rosse (BR: Red Brigades) and Prima Linea (PL: Front Line) in Italy, the Rote Armee Fraktion (RAF: Red Army Faction) and Bewegung 2. Juni (June 2nd Movement) in Germany, the Cellules Combattantes Communistes (CCC: Fighting Communist Cells) in Belgium, the Grupos de Resistencia Antifascista Primero de Octubre (GRAPO: October 1st Anti-Fascist Resistance Groups) in Spain, the Epanastatikē Organōsē 17 Noemvrē (17N: November 17th Revolutionary Organization) in Greece, and Devrimci-Sol (DEV-SOL: Revolutionary Left) and other groups in Turkey.
  3. secular right-wing groups – groups relying heavily on terrorism that seek to restore national greatness (radical nationalists), suppress “subversive” opponents (nativists), expel or subordinate troublesome ethnic and cultural minorities (racists), or overthrow the existing democratic and “plutocratic” capitalist systems in order to establish a revolutionary “new order” (neo-fascists). Some of the most important groups in this broad category have been Organōsis X (the X Organization) in postwar Greece, the Organisation de l’Armée Secrète (OAS: Secret Army Organization) in French Algeria, Aginter Presse and the Exército de Libertação Português (ELP: Portuguese Liberation Army) in Portugal, Ordine Nuovo (ON: New Order) and Avanguardia Nazionale (AN: National Vanguard) in Italy, the Aktionsfront Nationaler Sozialisten (ANS: National Socialists’ Action Front) and the Odfried Hepp/Walter Kexel group in West Germany, Westland New Post (WNP) in Belgium, the Grupos Antiterroristas de Liberación (GAL: Anti-Terrorist Liberation Groups) in Spain, the Bozkurtlar (Grey Wolves) paramilitary squads affiliated with the Milliyetçilik Haraket Partisi (MHP: Nationalist Action Party) in Turkey, the Frente Nacionalista Patria y Libertad (PyL: Fatherland and Freedom Nationalist Front) in Chile, vigilante (“death”) squads in various Central American countries, the Afrikaner Weerstandsbeweging (AWB: Afrikaner Resistance Movement) in South Africa, and the Minutemen in the U.S.
  4. religious terrorist groups – groups relying heavily on terrorism that seek to smite the purported enemies of God and other evildoers, impose strict religious tenets or laws on society (fundamentalists), forcibly insert religion into the political sphere (i.e., those who seek to “politicize” religion, such as Christian Reconstructionists and Islamists), and/or bring about Armageddon (apocalyptic millenarian cults). This type of terrorism comes in five main varieties: 1) Islamist terrorism; 2) Jewish fundamentalist terrorism, primarily inside Israel; 3) Christian terrorism, which can be further subdivided into fundamentalist terrorism of an Orthodox (mainly in Russia), Catholic, or Protestant stamp (which, in the U.S., is especially aimed at stopping the provision of abortions) and terrorism inspired by the idiosyncratic Christian Identity doctrine; 4) Hindu fundamentalist terrorism; and 5) terrorism carried out by apocalyptic religious cults. Some of the most important groups in these subcategories have been Islamist groups such as al-Qā`ida (the Base or Foundation; later renamed Qā`idat al-Jihād: The Base of the Jihad), Hizballāh (Party of God) in Lebanon, al-Harakāt al-Muqāwwama al-Islāmīyya (HAMĀS: Islamic Resistance Movement) and al-Jihād al-Islāmī al-Filastīnī (Palestinian Islamic Jihad, also known as PIJ) in Palestine, the Tanzīm al-Jihād al-Islāmī (Islamic Jihad Organization, also known as EIJ) and al-Jama`a al-Islāmīyya (Islamic Group) in Egypt, al-Takfīr wa al-Hijra (Excommunication and Migration) in North Africa, the Groupe Islamique Armé (GIA: Armed Islamic Group) and Groupe Salafiste pour la Prédication et le Combat (GSPC: Salafist Group for Preaching and Fighting) in Algeria, the Groupe Islamique Combattant Marocain (GICM: Moroccan Islamic Fighting Group) in Morocco, al-Jama`at al-Tawhīd wa al-Jihād (Unity of God and Jihad Group) in Iraq (later renamed Qā`idat al-Jihād fī Bilād al-Rāfidayn [The Base of the Jihad in Mesopotamia]), Jemaah Islamiyah (JI: Islamic Community) in island Southeast Asia, the Abu Sayyaf Group (ASG) in the Philippines, the Tālibān in both Afghanistan and Pakistan, and various jihadist organizations operating in South Asia; Teror Neged Teror (TNT: Terror Against Terror) in Israel; the Phineas Priesthood and the Covenant, the Sword, and the Arm of the Lord (CSA) in the U.S.; elements from Bajrang Dal (BD: Mighty Hanuman’s Army), the youth wing of the extremist Vishva Hindu Parishad (VHP: World Hindu Council) in India; and Aum Shinrikyō (Aum Supreme Truth) in Japan.

Some would also add single-issue groups to this list, i.e., groups relying on terrorism that obsessively focus on very specific or relatively narrowly-defined causes of various sorts. This category includes organizations from all sides of the political spectrum, e.g., animal rights groups such as the Animal Liberation Front (ALF); anti-communist groups such as the Cuban exile organization Omega 7, the Comando de Caça aos Comunistas (CCC: Communist-Hunting Commando) in Brazil, and the the Alianza Anticomunista Argentina (AAA: Argentine Anti-Communist Alliance or Triple A) in Argentina; and anti-abortion groups such as the Army of God (AOG) in the United States. Note, however, that these violent single-issue groups almost always fall within one of the broader ideological categories listed above, e.g., anti-abortion groups tend to fall into the Christian religious terrorist category and radical ecological groups tend to fall into the secular left-wing or secular right-wing terrorist categories, and for that very reason they should not be lumped into a separate ideological category.

Needless to say, groups from each of these four broad categories have distinct ideologies that help to explain what they are for and against, who their friends and enemies are, and what targets they believe they can legitimately attack, but it is also the case that even superficially similar groups within each of these categories and subcategories have their own distinctive and often idiosyncratic doctrines. Moreover, it should be emphasized that these major categories of terrorism are not entirely discrete. Some essentially ethno-nationalist terrorist groups, e.g., have had a Marxist gloss (the PKK, factions of ETA), a religious gloss (certain Sikh groups), or a combination of the two (factions of the IRA). In more recent times, essentially religious terrorist groups have also displayed acute nationalist sentiments (the Islamist groups HAMĀS and al- Jihād al-Islāmī in Palestine), and essentially ethno-nationalist terrorist groups have adopted an increasingly prominent religious coloration (important pro-Islamist factions within the Chechen separatist movement, such as that of Shamil Basayev).


These types of complexities need to be kept in mind when considering their motivations.


Note, e.g., the definition from Title 22 of the U.S. Code, Section 2656f(d): “Terrorism means premeditated, politically motivated violence perpetrated against noncombatant targets by subnational groups or clandestine agents, usually intended to influence an audience.” See Here there is one unnecessary restriction (e.g., terrorism can be “religiously motivated” or even “economically motivated” as well as “politically motivated”) and two outright errors (terrorism is not always perpetrated against “noncombatant targets,” and it is not only carried out by “subnational groups” or “clandestine agents” – the worst perpetrators of terrorism, historically speaking, have been states, who often openly employ their own security forces instead of “clandestine agents”), and the quintessential feature of terrorism – the carrying out of violence in order to influence a wider target audience – is wrongly qualified with “usually.” See note 3 below.


The one qualification that needs to be made here is that the term “terrorism” is only applicable in the context of asymmetrical conflicts, since as every good general knows breaking the morale of the enemy is an essential aspect of conventional military operations. Yet open warfare between the official military establishments of rival states, even when it encompasses violent attacks that are specifically intended to influence the psychological state, either of enemy troops or the enemy civilian population, cannot and should not be conflated with terrorism proper. One can certainly speak of atrocities or war crimes in the context of conventional war, but attempting to break the morale of the enemy in such a context can best be characterized as psychological warfare.


The best collection and analysis of definitions of terrorism can be found in Alex P. Schmid and Albert J. Jongman, Political Terrorism: A New Guide to Actors, Authors, Concepts, Data Bases, Theories and Literature (Amsterdam: North-Holland, 1988), especially pp. 1- 38. Many of the better definitions highlighted therein emphasize the centrality of carrying out violent actions with the conscious intention of exerting a psychological impact on a wider target audience. Although this work is now out-of-date and is crying out for a new edition, it is still the best single introduction to terrorism. The formal definition that MonTREP director and MIIS associate professor Jeffrey M. Bale has been using in his own classes on terrorism for over twenty years is as follows: “Terrorism is the use or threatened use of violence, directed against victims selected for their symbolic or representative value, as a means of instilling anxiety in, transmitting one or more messages to, and thereby manipulating the attitudes and behavior of a wider target audience or audiences.”


The mixed religious and nationalist motivations of HAMĀS and al-Jihād al-Islāmī are widely recognized, but it is the former that clearly predominates in these two groups (in contradistinction to the motives of their political rivals in the PLO). For the “conversion” of certain key Chechen separatist factions to Islamism and their increasing resort to terrorism, see Julie Wilhelmsen, “Between a Rock and a Hard Place: The Islamisation of the Chechen Separatist Movement,” Europe-Asia Studies 57:1 (January 2005), pp. 38-46; and Jeffrey M. Bale, “The Chechen Resistance and Radiological Terrorism,” unpublished report, July 2003. By “Islamism” we are referring to a radically anti-secular and anti-Western Islamic political ideology with both revolutionary and revivalist elements. The principal ideological characteristics of Islamism in all of its forms are an outright rejection of Western secular values, an intransigent resistance to “infidel” political, economic, social, or cultural influence over the Muslim world, an extreme hostility towards less committed and militant Muslims (who are sometimes even denounced as “apostates” or “infidels,” the process known as takfīr), and an insistence on the establishment of an Islamic state governed by a rigid, puritanical application of the shāri`a. See Jeffrey M. Bale, “Islamism and Totalitarianism,” Totalitarian Movements and Political Religions 10:2 (June 2009), esp. pp. 79-80. For more on Islamist doctrine(s), compare Emmanuel Sivan, Radical Islam: Medieval Theology and Modern Politics (New Haven: Yale University, 1990); Abderrahim Lamchichi, L’islamisme politique (Paris: Harmattan, 2001); and Ibrahim M. Abu-Rabi`, Intellectual Origins of Islamic Resurgence in the Modern Arab World (Albany: SUNY, 1996). See also the contrasting interpretations found in Martin Kramer, ed., The Islamism Debate (Tel Aviv: Tel Aviv University/Moshe Dayan Center for Middle Eastern and African Studies, 1997).