Lone wolf terrorism involves individuals who are not affiliated with a particular group, do not have a clear ideology, or who pledged allegiance to a group but did not have direct ties to any existing members. Understanding the radicalisation process that leads to such violence is critical for prevention.
While large-scale, highly coordinated plots carried out by recognised organisations have not vanished, fatal incidents increasingly originate from individuals acting on their own initiative, often referred to as “lone wolves”. These attackers may subscribe to a particular ideology or interact with extremist communities online, yet they do not necessarily receive formal in-person training or direct organisational resources.
Historically, lone terrorist scenarios are not new and date back to ancient times. The period between 1878 and 1934 was the era of anarchist terrorism where most actors were lone wolves because of the rejection of organised leadership. One of the earliest prominent lone wolf attacks was the assassination of US President McKinley in 1901.
What distinguishes the current wave is the way in which rapid radicalisation can occur online, particularly through social media, which allows for easy access to terrorist propaganda, and the ability to self-organise and commit violent acts with minimal face-to-face contact.
Youth involvement
Additionally, growing involvement of disaffected young people amplifies the risks of lone wolf terrorism. In some countries in the West, such as the UK, one out of every five terror suspects is under 18. Factors contributing to increasing the risk of young people becoming involved in violent extremism include:
In addition, minors often trigger fewer warnings within security frameworks, enjoy certain privacy protections, and, if apprehended, may be subject to less severe legal penalties. Together, these factors have produced a changing threat landscape, which requires rethinking conventional understandings of extremist violence and how best to prevent it.
The process by which disaffected young people become radicalised can be conceptualised using the ‘bathtub model’.
It likens the build-up of motivations to a bathtub being filled with water, where three different taps represent distinct categories of motivation: ideological, psychological and personal.
These taps pour into the tub at varying rates, symbolising how different factors influence the individual over time.
When the water level reaches the tub’s capacity and overflows, it reflects the moment an individual decides to commit an attack.
This model emphasises that lone wolf attacks are rarely the result of a single driving force but instead stem from a complex interplay of motivations unique to each individual.
Triggers and thresholds are key components in this model, explaining the factors that push individuals closer to action. Triggers, such as traumatic personal experiences, mental health issues, exposure to propaganda, or the desire to emulate other attackers, act as catalysts that accelerate the filling of the bathtub.
Conversely, the threshold symbolises the individual’s ability to contain these motivations and emotions. This threshold is dynamic, shaped by psychological stability, personal resilience, and moral or practical inhibitions. When a person’s threshold is lowered, perhaps due to mental instability, external pressures, or heightened exposure to triggers, the likelihood of the bathtub overflowing increases, making an attack more imminent.
In many such cases, the online environment accelerates radicalisation.
In 2002, it took an average of sixteen months for an individual to move from exposure to extremist material to executing an attack. By 2015, this period had shrunk by over 40%. Today, in some cases, radicalisation happens in mere weeks.
Platforms that rely on algorithms to promote highly emotive or provocative content can reinforce harmful biases and draw vulnerable individuals deeper into violent extremism. As a result, the once-lengthy process of developing extremist views may now transpire in a matter of weeks.
Simultaneously, the boundaries between political, religious and purely hate-fuelled acts are frequently blurred.
Aside from the general ease with which extremist material can be found online, there are three others key factors or triggers that can all lead to the bathtub being filled more rapidly:
A central feature of the recent rise in lone wolf terrorism is ideological flexibility.
Even when attackers declare allegiance to one group, they may incorporate grievances and narratives from multiple sources, mixing religious, political and conspiratorial ideas in ways that defy conventional labels. This shape-shifting tendency is facilitated by the vast reach of digital spaces, where media producers can target content to audiences seeking identity, belonging, and purpose.
Youth targeting by extremist groups has emerged as a particularly unsettling trend. Technologically savvy and spending much of their time online, younger users are especially vulnerable to manipulative propaganda and extremist recruitment. Islamic State Khorasan Province (ISKP), for instance, has developed a multilingual media strategy that disseminates content in Pashto, Dari, Arabic, Urdu, Farsi, Uzbek, Tajik, English, Russian and Turkish. The group encourages individuals to form ‘hybrid’ plots by offering online tutorials on building improvised explosive devices, procuring firearms, or selecting targets. For intelligence and police forces, the result is a rapidly proliferating network of potential terrorists or small terrorist cells.
Significant geopolitical events or heightened racial and religious tensions, can trigger sudden surges in radicalisation.
Foreign conflicts, for instance, can fuel anti-immigrant sentiment or encourage sympathy for causes like those championed by ISIL-affiliated groups. When combined with personal challenges, mental health issues, or feelings of marginalisation, these triggers may prompt an individual to consider violent action. Given the digital sphere transcends national boundaries, extremist rhetoric spreads instantaneously, often making threats appear and evolve with very little warning.
This is an excerpt from the Lone Wolf and Youth Terrorism Briefing.
Further Reading:
The number of countries recording a terrorist attack increased from 58 to 66, according to the 12th annual Global Terrorism Index (GTI). This...
The recruitment and indoctrination of youth by extremist groups are evolving rapidly, and traditional counter-extremism have struggled to keep pace,...
Evolving Patterns of Terrorism & Radicalisation in Western Democracies
