Quantitative research on terrorist recidivism remains surprisingly limited, despite heightened concern among policymakers, practitioners, and the general public. Several factors contribute to this situation, including restricted access to sensitive data and the difficulty of assembling samples large enough to support robust statistical analyses, given the inherent rarity of terrorist offending. In Belgium, more than 650 individuals were convicted of terrorism-related offences between 2006 and 2024. Drawing on Belgium’s Central Criminal Record, this study examines post-conviction trajectories of this population. Building on a first wave of research published in 2025, it benefits from an extended observation period (2006–2024) and a larger, more homogeneous analytical sample. The study pursues two objectives: first, to provide a detailed description of recidivism patterns—prevalence, timing, and offence types—within this population, and; second, to identify factors associated with reoffending using survival analysis and Cox proportional hazards models. Findings show that terrorist recidivism is exceedingly rare (2.5%; n = 10), whereas general recidivism (18.7%) predominantly concerns common criminal offences (e.g., traffic violations). Survival analysis indicates that the instantaneous risk of recidivism peaks within the first five years after conviction, followed by a sharp decline. Factors associated with recidivism include both classic criminological factors (e.g., prior convictions, gender) and variables specific to terrorism-related offenders (e.g., organisational affiliation and role). Criminal career duration also emerges as a key determinant of recidivism. The article concludes by discussing the study’s methodological limitations and the implications of the findings for prevention, risk assessment, and policy development.
This research note examines the use of artificial intelligence (AI) as a decision-support tool in the monitoring and evaluation (M&E) of preventing and countering violent extremism (P/CVE) programmes. Drawing on an actual programme involving a bystander awareness initiative, the analysis compares an AI-assisted M&E framework generated using Microsoft Copilot with the publicly available external evaluation of the programme. The research note critically assesses how AI tools may support rapid early-stage programme design, but only when embedded within human-centred evaluation processes that emphasise judgement, transparency, and ethical oversight. Implications for responsible integration of AI tools into P/CVE evaluation practice are discussed.
In recent decades, Salafi-Jihadi groups have capitalised on the proliferation of social media to establish a persistent online presence. In that time, their activity has evolved into the so-called Multiplatform Communication Paradigm (MCP), a strategy to establish a presence on multiple online platforms instead of focusing on a single platform. Previous research has examined the digital ecosystem through outlinks from social media platforms such as Twitter and Telegram. On these platforms, Salafi-Jihadis face disruption and account removal. As distribution methods evolve to avoid detection, data collection is often based on availability at a given time. In contrast, this research is the first to present a longitudinal study, spanning almost six years of outline sharing from a Salafi-Jihadi digital safe haven, the IS Rocket.Chat server. Here, IS supporters are free to operate without removal, and thus, the research provides valuable insight into how the ecosystem operates when it is not facing disruption. The research provides an initial overview of the outlink data and demonstrates the continued importance of platforms fulfilling the roles of beacons, aggregators, and content stores within the digital ecosystem. It also emphasises the role of human choices in domain selection, as not all rooms share the same combinations of URL. This suggests a vital new, human-centred avenue for research into terrorist exploitation of the internet.
White nationalism has been subject to considerable debate by academic and online communities alike. We contribute to this body of scholarship by investigating constructions of white nationalism by (presumably) white nationalists online. To accomplish this, we extract and examine 92,000 posts on the topic between 2013-2024 from 4chan’s well-known /pol/ board. Using a mixed methods approach, we combine soft clustering of large language modelling embeddings with qualitative thematic analysis. Our results identify discursive constructions of an ethnic, gendered, and religious identity on 4chan, supposedly denied self-determination. By synthesising scholarly definitions with 4chan expressions of white nationalism, we also aim to detangle these constructions from white supremacy to advance an academic definition. We suggest white nationalism broadly describes the belief that humanity is naturally divided into nations, with a white nation that possesses distinct ethnic, political, territorial, and sovereign claims. Specifically, white nationalism as expressed on /pol/ is a form of ethnonationalism which champions an imagined (white) political and territorial community, whose idea of meaningful sovereignty is contingent upon the free exercise of white political will to shape their collective destiny.
Violent non-state actors (VNSAs) are increasingly using commercial geospatial technologies – e.g., unmanned systems, geographic information systems, and the Internet of Things – to conduct attacks. We conduct qualitative content analysis on interviews of twenty subject matter experts (SMEs), informing why some VNSAs use geospatial technologies, and how they choose among available technologies to augment tactics, techniques, and procedures (TTPs). We find that experts note two key dimensions: barriers to adoption and the technical capabilities of threat actors. Our analysis helps to categorise risks and offers insights into both the relative prevalence of different kinds of attacks, and the mechanisms by which geospatial technologies may shift the threat landscape.
This research note examines how terrorism in Europe has transformed over the past two decades, arguing that ideology-based frameworks no longer capture the most significant developments. The research note identifies six cross-cutting trends that have reshaped contemporary terrorism in Europe: the virtualisation of radicalisation and recruitment; the rise of lone-actor attacks; the growing salience of mental health vulnerabilities; ideological hybridisation; changing demographics, particularly the increasing involvement of minors; and increasingly compressed radicalisation trajectories. The research note contends that these trends are deeply interconnected and driven primarily by the expanding role of digital technologies. Together, they have produced a “grey zone” of terrorism, which is characterised by lone attackers who radicalise primarily online, defy clear ideological categorisation, and combine fragments of political ideas with psychological vulnerabilities, developmental issues, and deeply held personal grievances. This grey zone complicates detection, prevention, legal attribution, and public debate. Most fundamentally, the resulting violence sits uneasily with traditional definitions of terrorism, requiring a reassessment of prevailing concepts of radicalisation and terrorism in Europe today.
The study of terrorism has expanded substantially since the attacks of 11 September 2001, yet a universally accepted definition remains elusive. Despite extensive scholarly and institutional efforts, the concept continues to be contested and politically charged. This article examines whether contemporary definitions of terrorism represent a meaningful departure from earlier conceptualisations or whether a stable definitional core persists. The paper analyses 470 definitions drawn from academic literature, governmental sources, and intergovernmental organisations using systematic content and frequency analysis. The findings reveal strong conceptual continuity. Core elements include violence or force, political objectives, fear or terror, threat, purposive and organised action, and psychological effects. These elements appear consistently across definitions formulated both before and after 9/11 and closely align with earlier consensus-based studies. Variations in the prominence of secondary elements, such as civilian victimhood, religious motivation, and tactical framing, reflect contextual shifts rather than substantive definitional change. The analysis suggests that the enduring absence of a universally accepted definition stems less from conceptual ambiguity than from the inherently political and normative character of the term terrorism. While full consensus remains unlikely, identifying stable core elements provides a robust analytical framework for research, policy development, and legal analysis. In this sense, the paper shows that little is genuinely new at the conceptual core of terrorism, but that this continuity can now be demonstrated on an unprecedented empirical scale.
In an age of rapid social and technological change, digital trace analysis is crucial for law enforcement and intelligence agencies. The massive volume, variety, and velocity of digital data pose a significant challenge in identifying relevant and unsuitable content. This study addresses these challenges by employing a lexicon-based classification to distinguish violent jihadist discourses from non-violent Salafist discourses. Using open-source transcriptions of jihadist and Salafist videos originally produced, translated or subtitled in English, the study identifies linguistic themes through the LIWC Grievance dictionary. Key findings indicate that Impostor, Soldier, and Weaponry themes are statistically discriminant for all violent jihadist discourses. Furthermore, group-specific markers emerged, such as Deadline for al-Qaeda, and Suicide, Surveillance, and Violence for the Islamic State. While these tools offer significant potential for large-scale data processing, the study emphasises the necessity of qualitative contextual analysis to mitigate algorithmic biases and false positives.
The re-emergence of Tehreek-e-Taliban Pakistan (TTP) in Pakistan has caught the state off guard. This research note details the evolution of the threat posed by TTP given the shift in the terrorist organisation’s ideology, strategy, and modus operandi, and highlights the differences between the present and previous waves of terrorism in the Khyber Pakhtunkhwa province. In doing so, it also brings to fore the much less explored role women often play in financing, facilitating, and – at times – carrying out terrorist activities. The new TTP leadership under Noor Wali Mehsud, as well as a different political context with the Afghan Taliban in power in Afghanistan since August 2021, once more make it imperative to focus on the twin subjects of extremism and terrorism in Pakistan. In its new iteration, the revitalised TTP needs to be reviewed in a different light. In this research note, these shifts are explored in detail, including its connection with the Afghan Taliban, a new leadership and the subsequent changes in ideology, tactical evolution, willingness to form new alliances, involvement of women, and an enhanced administrative structure make the current wave of TTP extremely dangerous.
This article argues that we should re-cast explanations of violent extremism and terrorism in terms of INUS-conditions: Insufficient but Necessary Parts of Unnecessary but Sufficient Conditions. First, I show that existing explanations of terrorism and critiques of such explanations often assume or even state expressis verbis that the conditions identified in such explanations must be either necessary or sufficient to do explanatory work. I then introduce the notion of an INUS-condition. It has been fruitfully employed in such fields as philosophy of science, forensic psychiatry, education theory, and the social sciences, but so far not in the study of terrorism and violent extremism. I first show by way of examples not related to terrorism how explanations in terms of INUS-conditions work. I then go on to illustrate that existing accounts in the literature on terrorism are best understood in terms of INUS-conditions. Finally, I lay out what all this means for the current and future study of terrorism and draw some conclusions.
This research note calls attention to the urgent need for clearer conceptualisation and cross-sector collaboration in addressing the emergence of Com networks. These are decentralised online networks, or communities, that combine elements of sexual exploitation, misogyny, violence, and extremism. These communities, often operating across mainstream and encrypted platforms, facilitate the circulation of extreme, violent, and sexually abusive content. Participants, predominantly young males, pursue notoriety, control, and belonging, while algorithmic amplification fosters escalation and desensitisation. Com networks illustrate what has been termed by Marc-André Argentino and colleagues as the hybridisation of harms, where distinctions between sexual, criminal, and ideological motivations are increasingly blurred. The involvement of young people both as victims and coerced perpetrators highlights the need for trauma-informed, gender-aware, and developmentally sensitive approaches to prevention and disengagement. Traditional frameworks for understanding radicalisation and online sexual exploitation are insufficient for this complex and fluid threat landscape. This note argues that recognising and responding to Com networks requires interdisciplinary collaboration between law enforcement, clinicians, and researchers, and a shift toward integrated digital safety and public health strategies. Addressing this convergence of harms is critical for reducing risks of violence and radicalisation among vulnerable youth.
This study describes the clientele of a specialised clinical programme addressing violent extremism (VE) and violent nihilism (VN) and examines whether referral source is associated with differences in ideological, clinical, and psychosocial profiles. Data from 170 individuals referred between 2016 and 2024 were extracted from medical charts. Variables included referral source, type of VE or VN, mental health and legal history, diagnoses, grievances, and social integration. VN was the most frequent presentation and was more often referred by health services, whereas religiously inspired VE was more frequently referred by security agencies. Security referrals were more likely to involve prior criminal offenses. Diagnostic profiles and grievance patterns were similar across referral sources. VE and VN emerge within trajectories marked by psychological vulnerability and cumulative grievances. Referral pathways reflect both institutional logics and evolving forms of polarisation. Results highlight the need for clinically oriented, multi-actor responses beyond security-based approaches. They also underscore the importance of assessing not only whether social ties exist, but how they function in relation to distress and identity.
Pakistan is one of the most populous Muslim countries in the world. It is also consistently among the world’s most violent states. Religious seminaries (madrassah, pl. madaaris) are often posited as the main cause of Pakistan-based Islamist violence that occurs within Pakistan and beyond. Here, we reorient the madrassah discussion from transnational security to domestic security for Pakistan and its citizens. First, we examine the household use of madaaris, as well as public and private schools. We find that madrassah utilisation is surprisingly stable and low across more than two decades. We next look for correlations between madrassah enrolments and violence within Pakistan. While we find either no correlation or a negative correlation between madrassah utilisation and violence across several specifications using various sources of data, we consistently find evidence that incidences of violence are higher in wealthier and more densely populated areas.
The goal of this research note is to introduce the Leadership for the Extreme and Dangerous for Innovative Results (LEADIR) dataset. LEADIR is an open-source relational dataset containing information on 280 terrorist groups and 295 terrorist leaders active between 2008 and 2017. We first explain how LEADIR was developed and the historiometric method used to collect and code group and leadership information. Next, we discuss key variables at both the group and leader levels. Using descriptive statistics, we also examine these variables in the context of existing terrorism research. Finally, we elaborate on the strengths and limitations of LEADIR. In doing so, we describe the ways in which LEADIR can be used to build on terrorism research.
Two recent publications attempt to support the usefulness of ideology in conceptualising trajectories of radicalisation and deradicalisation in terrorism research. Both papers translate ideology as the three dimensions of social action framing: diagnostic, prognostic, and motivational framing. This Article reviews the two papers to show that the measurement potential of the three frames is being lost in efforts to preserve the value of the concept of ideology. The question is raised: can we give up talking about ideology in terrorism research?
Despite the ongoing need for researchers, practitioners, and policymakers to identify and assess the online activities of violent extremists prior to their engagement in violence offline, little is known empirically about their posting behaviours generally or differences in their online behaviours compared to non-violent extremists who share similar ideological beliefs. In the past five plus years, Scrivens and colleagues developed a dataset of posting behaviours of violent and non-violent right-wing extremists (RWEs) found on Stormfront, the oldest, largest, and one of the most influential RWE forums. This work has been presented before key stakeholders around the world and has resulted in various peer-reviewed publications with studies ranging from examining developmental posting behaviours to examining posting behaviours during peak posting days. This Research Note examines policy and investigatory implications, methodological challenges, and avenues for future research on the online posting behaviours of violent and non-violent RWEs.
As environmental crises intensify, environmentally-motivated sabotage and violence (‘eco-tage’ and ‘eco-terrorism’) are likely to play a more prominent role in terrorism discourse. Building on research linking fictional depictions of political violence to public attitudes toward real-world instances, this article examines portrayals of eco-tage and eco-terrorism in influential fiction films from the past five decades. Contrary to claims that the media is too fragmented to shape opinion, it identifies consistent narrative patterns in these films with the potential to influence views on activism, legitimacy, and state repression. Analysing 32 commercially and culturally significant films released between 1972 and 2023 and applying Murray Smith’s Structures of Sympathy framework, the study identifies a strong negative correlation between the severity of violent acts and their moral justification, with more extreme violence typically portrayed as illegitimate. Commercially successful films tend to depict more severe violence, with binary depictions of heroes and villains most common, rather than morally complex portrayals. This narrative polarisation moderately correlates with box office performance and year of release, illustrating a broader trend towards reductive storytelling. This is the first study to systematically assess cinematic portrayals of environmental violence over time, offering a high-level typology to connect narrative trends with cultural and commercial dynamics. Identified groupings generate hypotheses for future research on the extent to which portrayals of environmental violence influence public perceptions, as well as how narrative framing in entertainment media shapes political attitudes and policy responses more widely
This response engages Clark McCauley’s article on the analytic value of ideology in the study of radicalisation and deradicalisation. McCauley raises an important and constructive challenge: whether the broadened conception of ideology proposed in my earlier article—drawing on Michael Freeden’s morphological theory and the ideological triangle model—can maintain empirical precision, or whether the established diagnostic, prognostic, and motivational frames of social-movement theory offer a more tractable alternative. In this response, I argue that the ideological triangle is designed explicitly for the individual level of analysis, addressing the subjective configuration of beliefs, emotions, and motivations most relevant to deradicalisation practice. While the structure of the triangle parallels movement-level framing, its purpose is distinct: to model how individuals internalise, interpret, and personalise broader ideological signals, especially in an era of increasingly hybrid, unstable, and individualised extremism. I further contend that Freeden’s morphological approach, when translated to the micro level, provides a necessary account of the internal conceptual architecture that renders frames meaningful and motivational. Although the empirical operationalisation of morphological ideology remains in early stages, it is both feasible and essential for understanding cognitive rigidity, ideological narrowing, and the potential for “repluralisation” during disengagement.
Should we leave ideology behind in our study of terrorism and terrorists? In this response to Clark McCauley’s article, I suggest three reasons why, despite the merits of his observations, ideology remains an important component in our understanding of terrorists. First, definitional ambiguity—while not unique to ideology—can be overcome. Second, the worlds of collective action frames and ideology are inherently intertwined. Third, while we need to be able to ‘measure’ ideology, a grading scale—such as the one I proposed—has arguably greater utility than one based on framing. Ultimately, we need to adopt an inclusive approach that draws out the complex relationship between ideology and the multiple other components that coalesce in processes of terrorism.
This paper examines ideology and motivation in terrorism through a psychological lens, responding to a debate about the analytic value of ideology. Drawing on Peters’ concept of reason-guided, socially embedded action, and integrating rule-governed behaviour and Relational Frame Theory, it argues that terrorist behaviour is shaped by verbally mediated rules rather than simple causal mechanisms. This perspective aligns partially with social-movement framing theory, but highlights individual level processes. Conceptualising ideology as a dynamic process of rule governance offers a workable framework for understanding terrorist motivation and may help address the low base-rate problem in terrorism research.
