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Reasons for Leaving Terrorist Organizations

Mainstream thinking suggests that military tools are required to eradicate terrorism (see the post-9/11 war in Afghanistan and the current war against ISIS in Syria and Iraq, as well as U.S. President Trump’s many proclamations on the subject). Research on how and why individuals disengage from terrorist activity, however, suggests that there are viable non-military options for addressing terrorism.

Building on previous studies that identified a range of “push” and “pull” factors facilitating terrorist disengagement, the authors investigate which of these factors are more often associated with individuals’ decisions to leave terrorist organizations. Based on their assessment of existing research, they formed the following hypotheses: 1) in general, push factors will be more often associated with decisions to leave than pull factors will be; 2) de-radicalization (or the loss of ideological commitment) will not be the main factor in terrorist disengagement, nor will it be a necessary condition for disengagement; and, 3) individuals will be more susceptible to pull factors the less ideologically committed they are.

Hypothesized Push/Pull Factors for Terrorist Disengagement

Push Factors Pull Factors
  • Unmet expectations
  • Disillusionment with strategy/actions of terrorist group
  • Disillusionment with personnel
  • Difficulty adapting to clandestine lifestyle
  • Inability to cope with physiological/psychological effects of violence
  • Loss of faith in ideology
  • Burnout
  • Competing loyalties
  • Positive interactions with moderates
  • Employment/educational demands or opportunities
  • Desire to marry/establish a family or family demands
  • Financial incentives
  • Amnesty

Altier, M.B., Boyle, E.L., Shortland, N.D., Horgan, J.G. (2017). Why they leave: an analysis of terrorist disengagement events from eighty-seven autobiographical accounts. Security Studies, 26(2), 305-332.

To answer their research question, the authors analyzed 87 English-language autobiographies written between 1912 and 2011 by individuals previously (or in some cases currently) involved in terrorist organizations in various capacities (from the “bomb maker” to the “lookout,” from “those responsible for propaganda” to the “individuals who plant a bomb or pull a trigger”). Terrorist organizations from across the political spectrum (rightwing and left-wing) and motivated by a range of concerns (nationalist/separatist, religious, etc.) are represented in these autobiographical accounts. The authors identify 185 “engagement events” (“period[s] of sustained involvement in a terrorist group”) from these accounts and 170 “disengagement events” (“sustained period[s] of time in which the individual remains uninvolved in a terrorist group following a period of involvement”). These disengagement events can be broken down into two types of categories: collective or individual, and voluntary or involuntary.

The authors are most interested in the factors correlating with individual, voluntary disengagement—in other words, those cases where someone decided to leave a terrorist organization, as opposed to being forced to leave (and in the absence of the whole organization turning away from terrorism). Through statistical analysis, they determine which push and pull factors were most often experienced before—and/or credited as playing a role in—decisions to leave terrorist organizations, as compared to cases of involuntary disengagement.

In the end, they find support for all three hypotheses. First, push factors are more common motives for leaving terrorist organizations than pull factors are. Although pull factors are still important to decisions to disengage in some cases, the authors did not find a significant relationship between pull factors and decisions to disengage. The push factors most associated with decisions to leave were various forms of disillusionment (with the group’s strategy or actions, its leaders, its other members, or one’s day-to-day activities), as well as burnout. Second, although “loss of faith in ideology” was reported as playing a role in decisions to leave a terrorist organization 29% of the time, it was not the most common reason and was certainly not a necessary precondition for leaving. And, third, individuals who were less ideologically committed at the time of leaving a terrorist organization were more likely to report pull factors playing some role in their departure than those who were more ideologically committed. It is unclear, however, whether this is because their lower level of ideological commitment made them more susceptible to pull factors or because these pull factors may have played a role in diminishing their ideological commitment.

Push Factors: Experiences related to one’s involvement in terrorism that drive him or her away.

Pull factors: Influences outside the group that attract one to a more traditional social role.

Terrorist activity: The calculated use of unlawful violence or threat of unlawful violence to inculcate fear, intended to coerce or to intimidate governments or societies in the pursuit of goals that are generally political, religious, or ideological. (U.S. Department of Defense)

See discussion on the debate around definitions of terrorism in our analysis on domestic right-wing terrorism.


Despite the widespread belief that violence—in this case, terrorist violence—can only be met with violence (i.e., military action), this research brings to light some of the ways in which military action against terrorism may not be an effective tool for weakening terrorist organizations, at least through the mechanism of individual disengagement. Other research suggests the same on a broader level: a RAND study found that only 7% of terrorist organizations end as a result of military action against them (Jones & Libicki 2008). Military action is assumed to work, in part, by coercing the target group through the threat or use of violence that could hurt members of that group, yet, according to this study, “fear of being a victim of violence” was one of the least-experienced and least-cited push factors by those who ultimately decided to leave their terrorist organizations. In other words, decisions to leave were not largely influenced by the threat of military violence against them. Instead, the prominence of disillusionment as a primary factor motivating disengagement points to the way in which military action might actually be counterproductive insofar as it could strengthen one’s commitment to a terrorist organization and/or weaken disillusionment processes by creating greater cohesion among members of the organization (in opposition to a common enemy). Likewise, military action could also decrease individuals’ uneasiness over the terrorist activities in which they are engaged when these are used to counter clear military violence. More broadly, with regard to military strategies against organizations like ISIS, we must consider how military action will influence the various push and pull factors that facilitate terrorist disengagement. Will military action contribute to these factors and thereby encourage terrorist disengagement—or will it actually strengthen the commitment of individuals to continue their engagement in terrorism? What more effective nonviolent options might exist for influencing these push and pull factors?


As the authors note, this research highlights the value of focusing on activities that influence the push factors associated with terrorist disengagement, while also not neglecting activities that influence pull factors. Though pull factors are found to be less prominent than push factors in decisions to disengage from terrorism, they still play an important role in many decisions. Creating policies and programs that influence push factors is more difficult, however, than creating ones that influence pull factors, as outsiders have little control over the internal workings of a terrorist organization or an individual’s experiences in that organization. But, as the authors suggest, there may be interesting interactive dynamics to explore between push and pull factors. One possibility is to encourage alternative voices from credible/authoritative sources that provide counter-narratives to those offered by a terrorist group (for more on this idea, see Horgan 2009). The more someone involved in a terrorist organization is exposed to these outside interpretations (a pull factor), especially of the actions carried out by the terrorist organization to which s/he belongs, the more likely s/he may be to begin to note inconsistencies or negative qualities within that organization, leading to disillusionment (a push factor). More generally, the most effective efforts will be those that highlight such inconsistencies between a group’s ideology and its actions (such as ISIS’s killing of Sunni Muslim civilians on whose behalf it purports to be fighting), though special attention must be given to how and by whom that message is communicated.


  • “Push factors” are more commonly linked to decisions to leave terrorist organizations than “pull factors” are.
  • The most prominent “push factors” in terrorist disengagement are forms of disillusionment (with the group’s strategy or actions, with the group’s leaders, with other members in the group, and with one’s day-to-day activities), as well as to some extent burnout.
  • “Loss of faith in ideology”—what is often called de-radicalization—is not the most prevalent reason given for leaving a terrorist organization and is definitely not a necessary precondition for disengagement.
  • Less ideologically committed individuals are more likely to report “pull factors” playing some role in their decision to leave a terrorist organization than those who were more ideologically committed at the time of departure.


Altier, M.B., Boyle, E.L., Shortland, N.D., Horgan, J.G. (2017). Why they leave: an analysis of terrorist disengagement events from eighty-seven autobiographical accounts. Security Studies, 26(2), 305-332.

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