In this article, we will examine the issue of terrorism in the context of international relations. Reviewing the scholarly literature on terrorism, we shall attempt to define the term terrorism, and within that examine the disagreements academics and policymakers have regarding terrorism definitions. In addition, in this article, we shall also examine that various factors that are said to cause terrorism. According to Crenshaw (1981), “the study of terrorism can be organized around three questions: why terrorism occurs, how the process of terrorism works, and what its social and political effects are” (379). In this article, we will be looking at what the academic literature says in regards to the questions of why terrorism occurs, how actors commit acts of terror, and what the effects of terrorism are. We will then have a references section at the bottom of the article. 

What is Terrorism? Terrorism Definition

Terrorism is one of the most contested definitions in the field of international relations. Scholars have and continue to debate what is terrorism, as well as what causes terrorism. Often, many use the term, knowing the idea of terrorism, but not the detailed definition (Hoffman 2013). There are many definitions of terrorism, but it still becomes a challenge to agree upon what classifies a “terrorist” and “acts of terror.”

Hoffman (2006) states that “terrorism is thus violence–or, equally important, the threat of violence–used and directed in pursuit of, or in service of, a political aim” (3).

Viotti & Kauppi (2013) define terrorism as “[p]olitically motivated directed against noncombatants and designed to instill fear in an audience” (256).

According to the United States Federal Bureau of Investigation (FBI, 2014),

“18 U.S.C. § 2331 defines “international terrorism” and “domestic terrorism” for purposes of Chapter 113B of the Code, entitled “Terrorism”:

“International terrorism” means activities with the following three characteristics:

–Involve violent acts or acts dangerous to human life that violate federal or state law

–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

–Occur primarily outside the territorial jurisdiction of the U.S., or transcend national boundaries in terms of the means by which they are accomplished, the persons they appear intended to intimidate or coerce, or the locale in which their perpetrators operate or seek asylum.*

“Domestic terrorism” means activities with the following three characteristics:

–Involve acts dangerous to human life that violate federal or state law;

–Appear 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

–Occur primarily within the territorial jurisdiction of the U.S.”

Anderson, Peterson, Toops, & Hey (2015) write of terrorism: “Terrorism is a strategy by which subnational groups not recognized as legitimate by the states they oppose seek to resist those states by targeting nonstate actors, disrupting the flow of everyday life, and spreading generalized fear among the populations of those states. Terrorism a primarily a xommicative act, not a strategic one. It is a technique through which groups seek to provoke a military or political response as a form of recognition. Terrorism may also seek to demoralize the citizens of a state and so undermine support for the regimes they oppose” (414). 

Scholars have attempted to streamline the definition, aiming to agree on certain aspects of the terrorism definition. For example, Alex P. Schmid (2011) has put together a “Revised Academic Consensus Definition of Terrorism.” Regarding the definition of terrorism, Schmid writes:

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 is predominantly 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.

Yet, as we know, there is still not full agreement on the exact definition of every aspect of terrorism, although, as Tore Bjørgo (2005) argues, that many due accept the idea that “terrorism is a set of methods or strategies of combat than an identifiable ideology or movement, and that terrorism involves premeditated use of violence against (at least primarily) non-combatants in order to achieve a psychological effect of fear on others than the immediate targets” (2).

We have to keep in mind that these definitions have changed. As scholars have argued, this term terrorism has shifted meanings over the years (for a detailed discussion about the evolving nature of the definition of terrorism, see Bruce Hoffman’s writings in his book Inside Terrorism), and arguably continues to do so. And as Hoffman (2006) says regarding attempts to define terrorism,

“[i]n the past, terrorism was arguably easier to define than it is today. To qualify as terrorism, violence has to be perpetrated by an individual acting at the behest of or on the behalf of some extent organizational entity or movement with at least some conspiratorial structure and identifiable chain of command. This criterion, however, is no longer sufficient. In recent years, a variety of terror movements have adopted a strategy of “leaderless networks” in order to thwart law enforcement and intelligence agency efforts to penetrate them” (38).

Many continue to debate what would be categorized as “terrorism.” In fact, one of the critiques of current terrorism definitions has to do with the include, or the lack thereof of the state as a perpetrator of violence. For example, Glenn Greenwald, in his article “The Sham “Terrorism Expert” Industry argues, among other points, that many “terrorism experts” have had a vary narrow idea of who commits terror action. As Greenwald (2012) states, “[terror experts]…generally fixate on Muslims to the exclusion of all other forms of Terror. In particular, the idea that the U.S. or its allies now commit Terrorism is taboo, unthinkable. Their views on what Terrorism is track the U.S. Government’s and, by design, justify U.S. government actions…”.

Other scholars do include state terrorism as a category of terrorism, well within the definition of terrorism. As Richard Payne (2013) says: “Our definition of terrorism as the use of violence to coerce or intimidate and to generally create widespread fear among the population clearly covers many states, both historically and now” (107). He goes on to say that governments use terrorism to intimidate those opposed to the state’s actions, that states have used terrorism to alter how society acts, or they have also used terrorism in the cases of genocide, a “deliberate and systematic killing of an ethnic, religious, economic, intellectual, or any other group of people” (107).

Thus, as we see, the discussions about what is defined as “terrorism” are not settled; states and individuals are still in disagreement about such a contested issue (for a discussion on the debate regarding definition of terrorism in the UK, see the BBC 2014 article “Terrorism Definition Should Be Narrower“).

History of Terrorism

Interestingly, Bruce Hoffman (2006) explains that “[t]he word terrorism was first popularized during the French Revolution. In contrast to its contemporary usage, at the time terrorism had a decidedly positive connotation.The system of regime de la terreur of 1793–94–from which the English word came–was adopted as a means to establish order during the transient anarchical period of turmoil and upheaval that followed the uprisings of 1789, and indeed many other revolutions” (3). Hoffman (2006) goes on to say that “…unlike terrorism as it is commonly understood today, to mean a revolutionary  or antigovernment activity undertaken by nonstate or subnational entities, the regime de la terreur was an instrument of governance wielded by the recently established revolutionary state. It was designed to consolidate the new government’s power by intimidating counterrevolutionaries, subversives, and all other dissidents whom the new regime regarded as “enemies of the people” (3). And as Payne (2013) says, “The Committee on Public Safety embraced terrorism in its efforts to rule France during a period that was regarded as a national emergency” (91), although many contested these actions. But while the term is relatively newer, terrorism has existed in international relations for at least over two thousand years.

For example, a group called the Zealots were killing Roman officials in order to push them out of control of Palestine. There was a also a group called the Assassins, where were active from the 11th-13th centuries, that were also carrying out killings of rivals. And in Spain, there were many actors who were involved in the Inquisition, killing and torturing people (Viotti & Kauppi, 2013). However, terrorism has continued to exist throughout the centuries. In the 1800s, there were many secular terror attacks that were focused on political terrorism. As Viotti & Kauppi (2013) explain, in the late 1800s, there were groups of anarchists who killed high-level political leaders in Europe (although these attacks were towards political leadership, and not the population at large) (339). In the 1900s, we began seeing terrorism against colonialism, with local populations striking against the imperialist powers, and the colonizers, in turn, using terror against the populations they colonized. There has also been terrorism during the Cold War, with groups operating under the Marxist-Leninist ideology. In addition, nationalist movements also turned to the use of terrorism, such as was the case with the Palestinian Liberation Organization in the 1970s, and more recently the formation of groups such as Hezbollah and Hamas, and their actions against Israel and its occupied of Lebanon (1982) or the Occupied Palestinian Territories (Viotti & Kauppi, 2013).

Causes of Terrorism

This is one of the major questions with regards to understanding terrorism. In fact, some scholars have asked whether we can know what causes terrorism? (Bjørgo, 2005). Scholars have in fact attempted to find factors that lead an individual to commit an act of terror, all the while recognizing that “Terrorism…is a complex set of phenomena, covering a great diversity of groups with different origins and causes…” (Bjørgo, 2005). This section will outline some of the key arguments and finding with regards to what are the causes of terrorism.

Bjørgo (2005) argues that when we are trying to understand the causes of terrorism, we must be aware that there are “structural” causes and “facilitators”. Some causes of terrorism are “preconditions” which “set the stage for terrorism in the long run” and precipitants, which “are the specific events or phenomena that immediately precede or trigger the outbreak of terrorism” (3). Thus, some events may set the conditions, but the person may not know about it, whereas other events may be more directly and immediately tied to a response (Bjørgo, 2005: 3).


As Crenshaw (1981) says, ” The first condition that can be considered a direct cause of terrorism is the existence of concrete grievances among an identifiable subgroup of a larger population, such as an ethnic minority discriminated against by the majority. A social movement develops in order to redress these grievances and to gain either equal rights or a separate state; terrorism is then the resort of an extremist faction of this broader movement. In practice, terrorism has frequently arisen in such situations: in modem states, separatist nationalism among Basques, Bretons, and Quebecois as motivated terrorism. In the colonial era, nationalist movements commonly turned to terrorism” (383). However, it is important to not that just because a group has grievances, this does not mean that they will commit actions of terrorism. Furthermore, many who do not fall in this category end up committing acts of terror (Crenshaw, 1981). That is why it is important to not that it is but one of many causes of terrorism.

Lack of Political Expression

A related cause of terrorism to grievances seems to be the lack of political expression of grievances. While this might be related to a specific group that is marginalized, it is far from necessarily the case. It may just be that the government is oppressive of all its citizens, unwilling to allow any sort of political expression (Crenshaw, 1981). This in turn may lead individuals to commit acts of terror against that said government.   It can be the case that these individuals are acting as a small subsection of the overall population, who while may be frustrated with the government, would not be willing to carry out such acts (Crenshaw, 1981). As Crenshaw (1981) argues, “[m]any terrorists today are young, well-educated, and middle class in background. Such students or young professionals, with prior political experience, are disillusioned with the prospects of changing society and see little chance of access to the system despite their privileged status” (384).

Crenshaw (1981) also argues that sometimes, one other factor may be a government action, that then leads to a response by individuals, leading to acts of terrorism. Crenshaw (1981), speaking on this issues, says:

There are numerous historical examples of a campaign of terrorism precipitated by a government’s reliance on excessive force to quell protest or squash dissent. The tsarist regime’s severity in dealing with the populist movement was a factor in the development of Narodaya Volya as a terrorist organization in 1879. The French government’s persecution of anarchists was a factor in subsequent anarchist terrorism in the 1890s. The British government’s execution of the heros of the Easter Rising set the stage for Michael Collins and the IRA. The Protestant violence that met the Catholic civil rights movement in Northern Ireland in 1969 pushed the Provisional IRA to retaliate. In West Germany, the death of Beno Ohnesorg at the hands of the police in a demonstration against the Shah of Iran in 1968 contributed to the emergence of the RAF” (385).

Economic Grievances

Along with political grievances, as well as the inability to express actions through the political system of the state, scholars have also argued that economic deprivation can also lead to an increase in terror attacks. Some, such as Bird, Blomberg, & Hess (2008) have suggested that the less one has, particularly compared to others may be the reason that some would commit such attacks. This could be compared to those in their communities, their country, or compared to others in another country. As Bird, Blomberg, & Hess (2008) argued, “[t]he perpetrators are those who believe that they have been disadvantaged by the status quo and the victims are those who they perceive as having benefited from it…” (260).

Ideological/Religious Motivations

Along with psychology, economic, political grievances, some causes of terrorism may stem from a particular ideology. This can vary, and of course differs from politics, although there of course can be overlap of these causes. With ideology, there is a belief in some idea, which in turn is the motivation for their behavior. For example, “Historically, Marxism-Leninism has proven to be powerfully attractive to individuals who seek a framework that enables them to understand not only why injustices exist in a society but also how to end them” (Viotti & Kauppi, 2013: 343). Some of the most recent attention to ideology has been when examining the motivations of Al Qaeda (Viotti & Kauppi, 2013) who emphasizes a puritanical interpretation of Islam in their actions.

Domestic Policies of a State

Scholars believe that a state’s domestic policy can lead to individuals committing acts of terror. This can be apparent based on various political actions, and numerous examples throughout the international system, and throughout history. For example, the conflict in Northern Ireland, and the resulting terror attacks that occurred throughout the years were at least partially motivated by what some saw as problematic British government policies in Northern Ireland. The same motivation could be argued for South Africa, where many were furious at the government’s apartheid policies, or with the Palestinian Liberation Organization, and what they saw as abusive policies by the Israeli government and military in the Palestinian Territories (Payne, 2013). Again, much of this may be policies of the state, or the perception that the state is unwilling to remedy these particular grievances (Payne, 2013), and thus the state becomes a political target due to their policies, perceived indifference of the  policies, or tacit approval of said policies.

Foreign Policy of a State

A government’s foreign policy positions and actions have also been known to be another cause of terrorism. For example, today, some have argued that recent terror attacks have been at least partially driven by their views on United States foreign policy in the Middle East and elsewhere. However, the issue of targeting a state due to their foreign policies are not a new phenomena. As Payne (2013) explains, one can look at the Roman Empire and see that some used terror to attack the Empire (93).

Psychological Causes of Terrorism

Some have looked at terrorism from the lens of psychology, trying to understand whether there are any mental disorders, or other psychological issues with individuals who commit such actions. For example, many have looked at a child’s upbringing to see if there were any issues, or any signs that may have led to future actions of terrorism. Yet as Viotti & Kauppi (2013) explain, while one might see some of these issues in some of the individuals who committed terrorism, “to dismiss all terrorists as mentally ill is simply wrong”, as there are many who have committed such acts of terror that did not fit this psychological profile (342). Within the field of psychology, some have looked at social psychology to help better understand the causes of terrorism, namely “the study of the relations between people and groups” to see if there were any factors in the individuals’ interactions that could help explain why they committed the act of terrorism. For example, some social psychologists look to see whether individuals that moved to new country felt like “outsiders” in this new environment, and if they then found places or groups that not only supported them, but also may have influenced them towards radical interpretations of faith (Viotti & Kauppi, 2013) or had a role in convincing them to carry out acts of violence.

Combined Factors

While these different causes of terrorism can show up or not show up depending on the case, what we also have to remember is that, in many instances, these factors overlap; For example, when looking at poverty, this may be in combination with political frustrations, a government’s domestic or foreign policies, ideology, etc… Thus, one should remember that there is no one factor that is the cause of terrorism, but rather, it seems to depend on the individual. In some cases, poverty, coupled with grievances, seems to have been the driving forces for an act of terrorism, whereas in other cases, it may have been religious motivation, combined with domestic and foreign policy frustrations of a state, etc… In other cases, it has been psychological, in combination with ideology, etc… There is no one cause of terrorism, and when one examines the number of cases of terrorism, one can see just how different the motivations of actions can be. This is also important because it reminds us that terror attacks do not happen from one religious community or group disproportionately more than population figures (for a discussion on this point as it relates to Islam, see Sadowski, 2006), but rather for the various reasons mentioned above.

Why do People Commit Terrorism?

Having examined the various causes of terrorism, it is also important to look at the question of why people, who may be marginalized, political frustrated, etc… view terrorism as an option, as opposed to other political means. Because, as we see, there are many who fall under these categories of political marginalization, or economic poverty, and yet, do not commit terror attacks. The question is, for those that do carry out acts of terrorism, why they chose to do so. As we can imagine, there are many explanations for this as well. Bird, Blomberg, & Hess (2008) suggest that those who do so feel that there is no better option, whether they are speaking against biases of their own government, other states, or the international economic system and actors within that said system.

Terrorism as a Political Tool

Organizations that decide to use terror methods often do so because they think that it is an effective mechanism against their target, such as the government (Crenshaw, 1981). As Dekmejian (2007) explains, “[t]he conflicts between the state and opposition groups can be viewed as an interaction process, with an asymmetry of power favoring the state. In a some cases, violence by the state will be countered by nonviolent campaigns either because the opposition is too weak to use violence or it desires to hold the moral high ground and garner international support. However, in other instances, the opposition may choose to use terrorism” (18). And even when the government is not using violence, an individual or group might at times still uses such acts of violence for what they think will be political advantageous.  Others use terrorism while fighting a war. This might differ from non-war conditions within a state, but for some, it is a tactic during conflict. 

Does Terrorism Work?

However, one question regarding acts of terrorism is whether these tactics have actually worked for an organization, particularly within the context of aiming to gain some sort of benefit from the government. Max Abrahms looked at this question in his paper “Why Terrorism Does Not Work,” which was published in the journal International Security in 2006. In his work, Abrahms, looked at the stated objectives of 28 terrorist organizations since the year 2001. After examining their actions and objectives, Abrahms found “two unexpected findings. First, the groups accomplished their forty-two policy objectives only 7 percent of the time. Second, although the groups achieved certain types of policy objectives more than others, they key variables for terrorist success was a tactical one: target selection. Groups whose attacks on civilian targets outnumbered attacks on military targets systematically failed to achieve their policy objectives, regardless of their nature” (43). And in a later paper that revisits this question with expanded data, Abrahms (2012) similarly finds that governments are much less likely to grant concessions when citizens are attacked, compared to when the state’s military is the target.

Others have looked at this question and found some different results, although it depended on the context of the situation. For example, Eric D. Gould and Esteban F. Klor, in their 2010 paper entitled Does Terrorism Work, looked at terror attacks in Israel from 1988-2006. They found that “local terror attacks cause Israelis to be more willing to grant territorial concessions to the Palestinians. These effects are stronger for demographic groups that are traditionally right-wing in their political views. However, terror attacks beyond a certain threshold cause Israelis to adopt a less accommodating position. In addition, terror induces Israelis to vote increasingly for right-wing parties, as the right-wing parties move to the left  in response to terror.” They go on to say that “…terrorism appears to be an effective strategy in terms of shifting the entire political landscape to the left…”. And in a 2007 paper written by William Rose, Rysia Murphy, and Max Abrahms, they look at the 2004 Madrid bombings, and argue that in this particular case, “[t]he terrorist group that carried out the attack sought to compel Spain to withdraw its troops from Afghanistan and especially Iraq[,]” and were successful in having the state do so. However, they point out that there are “uncommon” conditions that have lead to a group reaching their stated goal(s).

Terrorism and Communicating a Message

Direct political concessions may not be the only goal of a terrorist organization. For example, Dekmejian (2007) explains that sometimes the primary objective for such actions by individuals or groups is also to send signals either to other members of the group, a state, the public, or the world at large (19). Thus, their goals may be to strike fear, to show some sort of influence, or to attract other people into their group (19).  And the rise of the spread of media has played a role in this discussion, as groups use the spread of media (such as television and the internet) for furthering their messages (Dekmejian, 2007: 19).

Costs Regarding Terrorism/Responses to Terrorism

There are a number of costs to terrorism. For example, the effects of terrorism alter the lives, as well as responses of individuals, non-government actors, and state actors. For example, when looking at the individual, Payne (2013) explains that “Individuals usually suffer the most  from terrorist acts in terms of loss of lives and social, psychological, and physical problems. Many citizens are made ill by fear, and a sudden loss of personal freedom” (97). In addition, what terrorism also does it build tension and “undermine[s] trust” between members of the community, such as was the case between the Arab and Muslim communities in the United States, with their neighbors (Payne, 2013) As we see, there are still numerous forms of Islamophobia and racism towards Arabs and other communities (such as the Sikh community) because of the effects of the September 11th, 2001 terror attack on the United States, and according to reports, sadly, there are many in the United States who think it is permissible to restrict the rights of Muslims and Arabs due to these concerns. Some individuals sadly generalize about an entire group, which continues to promote misunderstanding, instead of peace, acceptance, and the importance of a seeing ourselves as a global human community.

In addition to the individual costs associated with the effects of terrorism, there are also economic costs to terrorism.  According to scholars, the terrorist attack committed could have greats effects on the international economic system. For example, as Richard Payne (2013) explains, “after the 2001 attacks [on the United States], airlines suffered major financial losses and continue to feel the impact of terrorism. It is estimated that the global airline industry lost $18 billion in 2001 and $13 billion in 2002 following the attacks” (97). Furthermore, it could also effect how states act. For example, a state, following a terror attack, or even a threat of terrorism, may began increasing their budgets on surveillance, security, and counterterrorism measures. Or, they may also alter their foreign policy actions or relationships with states following an attack (Payne, 2013).



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Viotti, P. R. & Kauppi, M. V. (2013). International Relations and World Politics (5th Edition). New York, New York. Pearson.

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