This CREST report identifies and analyses 11 themes from the post-2017 research on disengagement and deradicalisation.

Executive summary

An urgent need exists for an empirically grounded understanding of the processes that lead individuals to disengage and deradicalise from terrorism and violent extremism. It is only with such empirically driven knowledge that appropriate interventions and programmes to assist in the successful reintegration of former terrorists and violent extremists can be designed, validated, updated, and implemented.

This report provides a systematic review of the post-2017 research on disengagement and deradicalisation. After screening more than 83,000 documents, we found 95 reports which met the criteria for coding. This sample of reports was coded across eight core coding themes and a total of 123 individual variables. 

Through the process of a systematic quality review, 29 articles were identified as meeting the criteria for full thematic analysis. In addition to this, the 30 most heavily cited pre-2017 papers on disengagement and deradicalisation were identified to be used as a comparative sample for the post-2017 publications.

The analysis of that collection has allowed us to identify the major factors involved in these processes and to assess the extent to which knowledge and understanding is progressing in this critical field.

Overall, the review found clear evidence of progress in our understanding of disengagement and deradicalisation. Comparison with the pre-2017 literature illustrates that valuable research is being conducted and published in the recent period using more robust research methods and which is providing new data for analysis and insight.

The review found that research had identified a range of facilitative causes and barriers for disengagement and deradicalisation, though work is still needed to determine the weighting of these. Encouragingly, the review also found that the available evidence suggests that many interventions examined appear to have positive impacts. Relapse and recidivism occur but appears to be uncommon. 

Eleven major themes across the post-2017 research were identified and analysed:


The literature emphasised that what consistently differentiates those who have psychologically disengaged from others who have physically disengaged is opportunity. These opportunities can be provided by a new life with family, a new career, or a new sense of self-worth, or even an individual’s incarceration. The evidence demonstrates that it is not enough to disagree with the strategies, tactics, and ideologies of the movement/groups an individual is affiliated to. Alongside this must be the perceived opportunity to safely, and permanently, exit.


Those who leave terrorist and extremist groups are invariably disillusioned with some aspect of life in the terrorist or extremist organisation. This can relate to disillusionment with personnel, disillusionment with strategy, or disillusionment with the day-to-day reality of membership. While the role of disillusionment is oft-noted, without the combined opportunity of exit it will not necessarily result in disengagement.


For the previously mentioned opportunity to be successful it must be offered by a trusted individual or organisation, in the eyes of the individual(s) disengaging. Without that trust, their engagement in the extremist lifestyle may be further prolonged.

When designing any disengagement, deradicalisation, and/or reintegration initiatives trust must be central. If those individuals and/or organisations administering the programmes are trusted, then there is a greater opportunity for success.

With trust in place, there is more likely to be a positive attitude towards the programme. This positive attitude is shaped by social relations and relational trust. Knowing who is most trusted, and who is distrusted, and by who is essential knowledge in the design stage of any successful programme. This must be constantly reviewed and reassessed throughout the delivery of the programme.

Family and friends

The trusted individual(s) providing the opportunity/opportunities for disengagement from extremist organisations need not be external organisations. The most successful facilitators of disengagement can at times be an individual’s family members or social connections. Family members and friends are oftentimes uniquely positioned to challenge and support the extremist in parallel.

One familial relationship that does have a more significant relationship with disengagement and deradicalisation is if the extremist is a parent themselves. Parenthood may not move an individual away from the maintenance of an extremist ideology, however, it may lead them to refrain from engagement in violent activity.


A major finding is that imprisonment is a recurring facilitator of the disengagement and deradicalisation process. This happens through three major pathways:

  1. Prison provides an opportunity for reflection
  2. Prison physically disengages the individual from the group and/or other extremist individuals
  3. Prison provides an opportunity to engage with disengagement and deradicalisation interventions.

Prison is often portrayed as or assumed to be a hothouse of radicalisation, though the disengagement literature paints a different picture, where instead it is a dominant setting for disengagement.


Identity issues have previously been flagged as a key factor in radicalisation processes, and the review found that identity is also a major theme in disengagement and deradicalisation processes. The role of identity across the studies varied with different issues flagged, including:

  1. the rejection of an existing extremist identity
  2. the search and elevation of an alternative identity
  3. the transformation of a militant identity into a peaceful identity that still embraced many similar values.

Overall, the findings suggest a key role for identity dynamics in disengagement and deradicalisation processes, but that the nature of these dynamics and outcomes varies on an individual basis.

Impact of disengagement and deradicalisation programmes

The review found that disengagement and deradicalisation programmes generally work. Most participants report or show some positive impacts for most programmes. There is, however, considerable variation in terms of how the impact of programmes is measured and not enough data is currently available to assess which programmes are the most effective. 

Use of formers

The potential role of former terrorists was focused on in eight of the shortlisted articles. The studies highlighted that formers have been used in a variety of different contexts and across a range of terrorist ideologies and movements.

The review found a range of potential benefits for using formers in disengagement and deradicalisation work, including the enhancement of knowledge about exits, the credibility of formers, and the possibility of formers acting as role models. However, no study has yet provided a clear-cut impact evaluation of the effectiveness of formers.

Another factor that was highlighted is that involvement in disengagement and deradicalisation work assists the formers themselves with their own reintegration process.

The general theme across the different studies was that allowing formers to be involved in such work can be beneficial in terms of cementing and protecting their own disengagement process.


In thinking about facilitators for disengagement and deradicalisation, one barrier identified in five articles related to security. In general, individuals felt their physical safety and security could be threatened or at risk if they disengaged from the extremist movement. These concerns could act as a deterrent for change and also posed a risk for reengaging.

A significant conclusion was that disengagement and deradicalisation interventions need to have concrete elements focused on protective measures for disengaged former extremists. Individuals who remained or became vulnerable to threats or violence from former comrades could be deterred from disengaging or coerced later into returning to the movement.

Mental health

The potential role of mental health in radicalisation processes has attracted considerable attention, but its potential role in disengagement and deradicalisation has been much less explored.

The review found that stress and burnout were the mental health issues most closely connected to disengagement and deradicalisation processes from terrorism. Mental health issues were also considered in terms of the post-disengagement phase. Discussions in this regard focused on the potentially harmful consequences of having being involved in violence and conflict situations. Studies highlighted that individuals may be suffering from trauma-related mental health issues such as PTSD.

Overall, these findings illustrated that a requirement for psychological support could be an important factor in the successful reintegration of individuals from a range of extremist groups and conflicts.


Former militants face a variety of challenges concerning reintegration. Among the main challenges identified in the articles were:

  1. the stigma associated with past offending
  2. building a new positive identity
  3. accessing practical, economic, and psychological support.

Many are highly conscious that their previous terrorist/extremist history will be seen negatively by the community around them and qualitative studies highlight some evidence of stigma experienced by former extremists.

When one considers the quality of the research data, though improved, it still lags behind the standards common in many other areas. Though a large number of studies were initially identified as relevant, ultimately very few made the quality benchmark criteria we set. Even among these studies, with a few exceptions, we note that in general, the majority relied on qualitative methodological approaches such as semi-structured interviews, autobiographical analysis, and case study analysis. With one notable exception, research rarely made use of comparison or control groups.

The review identified some important gaps in both our current understanding of important issues and also in terms of the quality of the evidence available to answer critical questions. We outlined where these gaps existed and provided recommendations for addressing them.

Read more
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