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Terrorism: Definitions, History, Types, and the Rise Since 1990
Criminology · Chapter 16: Political Crime and TerrorismSection 16.3 · lesson 68 of 91video coming soon
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In this lesson
Why the term resists definition, and what has changed since 1990.
- Explain why terrorism resists a single definition.
- Identify the elements most definitions share.
- Describe the principal typologies of political violence.
- Summarize developments in political violence since 1990.
Transcript
Everything said in the video, section by section (1,619 words). Read along, or search it.
Opening Question
Why Incident Counts Do Not Match
Two research teams count terrorist incidents in the same year, and their totals do not match. Is one of them wrong? Not necessarily. Terrorism is one of the most used words in public life, and one of the hardest to define.
Lesson Roadmap
What This Lesson Covers and Avoids
This lesson explains why that difficulty exists, and why it matters. We begin with the definitional problem, and the elements most definitions share despite it. We contrast legal definitions with academic ones, using actual federal and State Department examples. Then we look at the typologies the field uses, and at the historical record in outline. Next come the main developments in political violence since nineteen ninety. We examine the debate over causes, the radicalization literature, and the problems of measurement. The discussion stays analytical throughout, with no operational, tactical, or propaganda content.
Core Problem
Defining Terrorism Is Politically Contested
No single definition of terrorism commands universal acceptance. Governments, international bodies, and researchers all draw the line in different places. Part of the difficulty is genuinely political, not just technical. Applying the label carries real consequences: it can determine legal jurisdiction, and it brings public condemnation. Because so much rides on the label, the boundary of the definition becomes a contested resource. Different actors have reasons to draw it more broadly or more narrowly. So a definition does practical work, deciding which acts get counted, prosecuted, and condemned. That is why every definition of terrorism should be read alongside its source and its purpose.
Shared Elements
Four Features Most Definitions Share
Despite the disagreement, most definitions share several elements. The first is the use or threat of violence. The second is a political or ideological objective that the violence is meant to serve. The third is an intended audience beyond the immediate target. In other words, the act is deliberately meant to communicate or coerce beyond those directly harmed. Most legal definitions add a fourth element, a requirement that the actor be a non-state actor.
Disputed Element
Whether States Can Commit Terrorism
That fourth element is itself disputed, because some argue that state conduct meeting the same substantive criteria should also count as terrorism. That position connects to the discussion of state crime in Subchapter sixteen point one. Most domestic legal definitions, however, restrict the label to non-state actors. They address comparable state conduct through the separate international law framework covered there.
Legal Definitions
Federal, State Department, and Academic Definitions
Legal and academic definitions are built for different jobs. U.S. federal law defines terrorism for specific legal purposes, chiefly triggering jurisdiction and sentencing enhancement. Under Title eighteen, section twenty-three thirty-one, domestic terrorism involves acts dangerous to human life that violate criminal law. Those acts must appear intended to intimidate or coerce civilians, or to influence or affect a government. A separate provision defines a federal crime of terrorism: a listed offense calculated to influence or affect government by intimidation or coercion, or to retaliate against government conduct. The State Department, in its reporting, defines terrorism as premeditated, politically motivated violence against noncombatant targets, by subnational groups or clandestine agents. Notice that the non-state element is explicit there, while the criminal code definition does not state it. Academic definitions are broader still, because they are built for comparison across many cases. So never treat a legal and an academic definition as interchangeable.
Typologies
Four Ways to Classify Political Violence
The field classifies political violence along several dimensions. Classification by ideology groups incidents by the belief system invoked. Classification by scope separates domestic activity from international activity. Classification by organizational form distinguishes hierarchical groups from looser networks. It also separates both of those from individuals acting without any organizational direction. Classification by relationship to a state separates independent actors from those receiving state sponsorship. Each of these is useful for comparison, but each is a classification scheme with real limitations. Actual incidents often resist clean placement into a single category. An incident can involve mixed ideologies, cross borders, or blur the line between a network and an individual.
Historical Outline
Long History and Post-1990 Developments
At a general level, the historical record shows that political violence long predates the modern term terrorism. Recognizable patterns of ideologically motivated violence appear across the nineteenth and twentieth centuries. Those earlier episodes were simply described under other labels entirely. We treat that record only in outline, without operational or tactical content. Researchers describe several structural developments since nineteen ninety. First, a shift in organizational form, which we trace in a moment. Second, a changing role for communications technology, which has extended reach and enabled coordination across distances, an analytical observation, not a description of method. Third, a geographic redistribution of recorded activity across regions over this period. All three are observations drawn from published research, not claims about any particular group.
Organizational Shift
Three Periods of Organizational Form
Researchers trace the shift in organizational form across three broadly described periods. The first period features hierarchical organizations with centralized command. In that setting, prevention can target the leadership structure directly. The second features networked affiliates, with looser coordination across groups. Prevention then requires broader disruption, because there is no single command center. The third features individuals acting without direction from any organization at all. Here there is no organization to target, so prevention shifts toward community-level approaches. This is a general analytical shift, not a precise timeline. Its lesson is practical: prevention strategy has to follow the form that political violence actually takes.
Causes Debate
Three Levels of Explanation
Why do people take part in political violence? Explanations fall into three broad levels. Structural explanations emphasize broad social and political conditions. Organizational explanations emphasize group dynamics and the recruitment context. Individual explanations emphasize personal circumstance.
Research Finding
No Single Participant Profile Exists
Across this research, one finding is firm and consistent: no single profile characterizes those who participate in political violence. Participants vary widely across demographic, psychological, and socioeconomic measures. No reliable predictive profile has been established. That is where criminological theory contributes most, since structural, organizational, and developmental frameworks, several met earlier in this course, apply here. They treat political violence as shaped by conditions and group processes, not by any fixed individual type.
Radicalization
Process Models Are Not Prediction Tools
The radicalization literature describes how a person comes to adopt views supportive of political violence. It is a genuinely contested field, with several process models proposed. Each describes stages a person is theorized to pass through. Each has also drawn two main criticisms, beginning with limited predictive validity. They also oversimplify a process that varies considerably from one person to another. Recall the prediction limits from Subchapter six point seven, where even modest error rates produced many false positives. The same caution applies here, stated plainly. No radicalization model should be treated as a prediction tool, for picking out which specific individual will engage in political violence.
Quick Check
Is a Parking Dispute Punch Terrorism
Quick check. After a parking dispute, a man punches his neighbor. There is no political aim, and no message for anyone else. Under most working definitions, is that terrorism? Pause, and decide. No, it is not. Violence alone is not enough: there is no political objective, and no audience beyond the victim. It is a serious crime, but ordinary interpersonal violence, which most definitions exclude.
Measurement
Why Counting Political Violence Is Hard
Counting political violence consistently is genuinely difficult. As Chapter three showed, the purpose and choices of the organization behind a dataset shape what gets measured. Here, definitions disagree, reporting is inconsistent, and classification decisions vary across the organizations that keep datasets. So any trend claim should be read alongside the specific source and definition it relies on.
Open Question
Media Coverage and the Amplification Question
A second persistent question concerns the media, and it is sometimes called the amplification question. Does extensive coverage of an event serve the communicative goal such acts are theorized to pursue? And if so, what adjustment in coverage practice, if any, might be warranted? This lesson raises that question deliberately, without trying to resolve it. Reasonable people weigh the public's need to know against the risk of amplification differently.
Element Disputes
Each Element Generates Its Own Debate
Each shared element generates its own dispute. For violence or threat, the dispute is how broad a threshold should count. A broader threshold includes more incidents, but risks diluting the category's analytical usefulness. For a political objective, the dispute is separating a political motive from other motives in the same act. Excluding acts with mixed motives can undercount the phenomenon. For an audience beyond the target, the dispute is whether it can be verified apart from the actor's own stated intent. Requiring it excludes acts that are functionally similar but lack clear communicative intent. For the non-state actor requirement, the dispute is whether state conduct should be included. Excluding it routes comparable state conduct into the international law framework instead. Every working definition makes a choice on all four.
Applying Elements
Sorting Example Acts by Definition
Let's apply the shared elements to some example acts. Violence with a political objective and an intended wider audience qualifies under most working definitions. So does a threat of violence meant to influence government policy, with a broader audience in mind. An act meeting every element, by a non-state actor, clearly qualifies. Violence with no identifiable political aim does not qualify, and neither does unconnected interpersonal violence. State military action against another state's forces in armed conflict falls under the law of armed conflict instead. An act missing a clear audience, or mixing a personal grievance with a political motive, depends on the definition used.
Work Backward
Why Two Datasets Disagree
Now work backward. Two datasets disagree on how many incidents occurred. What is the likeliest cause? Pause, and decide. When two datasets disagree, the likeliest cause is different inclusion rules, such as mixed motives or state conduct. As the opening example showed, the chosen definition, not any factual dispute, drives much of the count.
Comparison
Which Definitions Count More Acts
Compare what different definitions count: broader academic definitions and state-inclusive definitions capture more acts. A definition that excludes mixed motives captures fewer acts.
Key Takeaways
Definition Choice Drives the Count
Let's pull it together. No single definition of terrorism is universally accepted, and each should be read with its source. Most share four elements, and each element is disputed. Research finds no single profile of participants. And the definition chosen drives much of the count.
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About Terrorism: Definitions, History, Types, and the Rise Since 1990
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