Defining Terrorism

FBI: “Domestic terrorism: Perpetrated by individuals and/or groups inspired by or associated with primarily U.S.-based movements that espouse extremist ideologies of a political, religious, social, racial, or environmental nature.” 


The FBI further defines a “federal crime of terrorism” as “an offense that is: (i) calculated to influence or affect the conduct
of government by intimidation or coercion or to retaliate against government conduct; and (ii) is a violation of federal statute.”

SOURCE: Federal Bureau of Investigation. “Domestic Investigations and Operations Guide.” 16 December 20008., p. 4.

FEMA:  “Terrorism is the use of force or violence against persons or property in violation of the criminal laws of the United States for purposes of intimidation, coercion, or ransom.”


USA PATRIOT Act of 2001: defines domestic terrorism as “activities that (A) involve acts dangerous to human life that are a violation of the criminal laws of the U.S. or of any state; (B) appear to be intended (i) to intimidate or coerce a civilian population; (ii) to influence the policy of a government by intimidation or coercion; or (iii) to affect the conduct of a government by mass destruction, assassination, or kidnapping; and (C) occur primarily within the territorial jurisdiction of the U.S.”


Terrorism Risk Insurance Act: Section 102(1)(a) defines terrorism as: “a violent act or an act that is dangerous to–(I) human life; (II) property; or (III) infrastructure; (iii) to have resulted in damage within the United States, or outside of the United States in the case of– (I) an air carrier or vessel described in paragraph (5)(B); or (II) the premises of a United States mission; and (iv) to have been committed by an individual or individuals as part of an effort to coerce the civilian population of the United States or to influence the policy or affect the conduct of the United States Government by coercion.” 


The Revised Academic Consensus Definition of Terrorism (by Alex P. Schmid)

The Definition of Terrorism

Terrorism is a contested concept. While there are many national and regional definitions, there is no universal legal definition approved by the General Assembly of the United Nations (the one proposed by the Security Council in Res. 1566 (2004) is non-binding, lacking legal authority in international law). The Ad Hoc Committee on Terrorism of the 6th (legal) Committee of the General Assembly has, with some interruptions, been trying to reach a legal definition since 1972 – but in vain. In the absence of a legal definition, attempts have been made since the 1980s to reach agreement on an academic consensus definition. The latest outcome is the revised definition reprinted below. It is the result of three rounds of consultations among academics and other professionals. A description how it was arrived at can be found on pp. 39 – 98 of Alex P. Schmid (Ed.). The Routledge Handbook of Terrorism Research. London and New York: Routledge, 2011. The same volume also contains 260 other definitions compiled by Joseph J. Easson and Alex P. Schmid on pp. 99 -200.

Revised Academic Consensus Definition of Terrorism (2011)

1. Terrorism refers, on the one hand, to a doctrine about the presumed effectiveness of a special form or tactic of fear-generating, coercive political violence and, on the other hand, to a conspiratorial practice of calculated, demonstrative, direct violent action without legal or moral restraints, targeting mainly civilians and non-combatants, performed for its propagandistic and psychological effects on various audiences and conflict parties;

2. Terrorism as a tactic is employed in three main contexts: (i) illegal state repression, (ii) propagandistic agitation by non-state actors in times of peace or outside zones of conflict and (iii) as an illicit tactic of irregular warfare employed by state- and non-state actors;

3. The physical violence or threat thereof employed by terrorist actors involves single-phase acts of lethal violence (such as bombings and armed assaults), dual- phased life-threatening incidents (like kidnapping, hijacking and other forms of hostage-taking for coercive bargaining) as well as multi-phased sequences of actions (such as in ‘disappearances’ involving kidnapping, secret detention, torture and murder).

4. The public (-ized) terrorist victimization initiates threat-based communication processes whereby, on the one hand, conditional demands are made to individuals, groups, governments, societies or sections thereof, and, on the other hand, the support of  specific constituencies (based on ties of ethnicity, religion, political affiliation and the like) is sought by the terrorist perpetrators;

5. At the origin of terrorism stands terror – instilled fear, dread, panic or mere anxiety –  spread among those identifying, or sharing similarities, with the direct victims, generated by some of the modalities of  the terrorist act – its shocking  brutality,  lack of discrimination,  dramatic or symbolic quality and disregard of the rules of warfare and the rules of punishment;

6. The main direct victims of terrorist attacks are in general not any armed forces but are usually civilians, non-combatants or other innocent and defenceless persons who bear no direct responsibility for the conflict that gave rise to acts of terrorism;

7. The direct victims are not the ultimate target (as in a classical assassination where victim and target coincide) but serve as message generators, more or less unwittingly helped by the news values of the mass media, to reach various audiences and conflict parties that identify either with the victims’ plight or the terrorists’ professed cause;

8. Sources of terrorist violence can be individual perpetrators, small groups, diffuse transnational networks as well as state actors or state-sponsored clandestine agents (such as death squads and hit teams);

9. While showing similarities with methods employed by organized crimeas well as those found in war crimes,terrorist violence ispredominantly political – usually in its motivation but nearly always in its societal repercussions;

10. The immediate intent of acts of terrorism is to terrorize, intimidate, antagonize, disorientate, destabilize, coerce, compel, demoralize or provoke a target population or conflict party in the hope of achieving from the resulting insecurity a favourable power outcome, e.g. obtaining publicity, extorting ransom money, submission to terrorist demands and/or mobilizing or immobilizing sectors of the public;

11. The motivations to engage in terrorism cover a broad range, including redress for alleged grievances, personal or vicarious revenge, collective punishment, revolution, national liberation and the promotion of  diverse ideological, political, social, national or religious causes and objectives;

12. Acts of terrorism rarely stand alone but form part of a campaign of violence which alone can, due to the serial character of acts of violence and threats of more to come,  create a pervasive climate of fear that enables the terrorists to manipulate the political process.

Reprinted from: A.P. Schmid (Ed.). Handbook of Terrorism Research. London, Routledge, 2011, pp.86-87.