Recent years have illustrated the threat posed by individuals undertaking terrorist acts on their own. Lone-actor violence has repeatedly captured media headlines, in particular since the adoption of run-over attacks. Clearly, this is a form of terrorism that must be taken very seriously for its proven ability to cause considerable numbers of fatalities. At the same time, our analysis of and response to the lone-actor phenomenon is marred by conceptual confusion and assumptions whose validity has been insufficiently tested. As the ways in which we perceive problems strongly influence how we deal with them, the lone-actor threat needs to be critical examined.

It has become common to find out that attackers initially labeled as lone actors later turn out to have had ties to other terrorist operatives or support networks. This is an important finding, but there is more to it than the mere fact that lone actors are often not as ‘alone’ as the name implies. In fact, through a 3-year research project supported by the EU, my colleagues and I found that the isolation typically assumed to define the lone actor is more often than not absent. From radicalization to the planning and preparation of actual attack, social ties to individuals or groups with radical or extremist convictions, or with past experience using terrorist violence, are typical. These connections play key roles in lone actors’ adoption and maintenance of the motivation to commit violent acts, for instance by providing them with ‘role models’ whose behavior they seek to emulate. For a minority of lone actors, such ties also resulted in concrete help with planning or preparing acts of terrorist violence.

While there are some individuals who fit the stereotypical image of lone actors as isolated loners, these are exceptions rather than the rule. Theodore Kaczynski (the ‘Unabomber’) and, more recently, Anders Breivik come to mind. But the majority of lone actors are men (and some women) who maintained ties to radical or extremist individuals, groups or social milieus; even if those ties were often tenuous or even if their particular personality characteristics prevented full integration or participation. Such findings matter not just because they argue for the need to adjust our perception of what typifies lone actors, but also because they point to potential avenues for early-detection and interdiction. If, for instance, police and intelligence agencies assume lone actors are truly isolated, they may miss chances to identify them through infiltration in extremist milieus.

Another point where our research challenges some of the conventional wisdom on lone actors concerns their operational capabilities. The popular ‘lone wolf’ designation conjures an image of individuals who are not just isolated, but stealthy and capable users of violence. Not only is the lone wolf moniker problematic because it essentially promulgates a term introduced by American right-wing extremists, it is also empirically untenable. As detailed in a recently published article, most lone actors ‘leak’ their intention to commit violence to others out of amateurism, inexperience or, perhaps most importantly, a desire for recognition and status. Moreover, most lone actors are poor at maintaining the operational security necessary to remain undetected by the authorities or vigilant citizens in the run-up to their attack. Inexperience and, at least in some cases, impatience make them vulnerable to detection and interdiction. These are not the lone wolves you are looking for.

All of this matters for the academic debate on lone actor terrorism. But perhaps even more so for the counterterrorism policy and practice that builds (at least in part) on insights garnered from the efforts of researchers. Assumptions need to be challenged not just to acquire a higher resolution of the subject under consideration, but because uncorrected they can prevent the formulation and execution of more effective counterterrorism measures.