While there is widespread agreement about the fact that nobody is born a terrorist, there is plenty of disagreement about why someone becomes a terrorist. Personal and situational push and pull factors combine as drivers to determine why and how usually young people become involved in terrorism. Rather than there being a single route to terrorism, there are many pathways for an individual to become a ‘violent extremist’ – a term often substituting for ‘terrorist’ (but even less well defined). To prevent an individual from following a path that ends in violence without moral restraints (namely attacking without provocation unarmed and unknown people) poses enormous challenges, especially in open societies typical of most North Atlantic Treaty Organization (NATO) members and most partner states as well. The search for a distinct ‘terrorist profile’ has been going on for many years, and, while most researchers have given up on the theme of finding the terrorist personality or a terrorist mind-set, others have not. However, the latter researchers readily admit that there are several personality traits rather than only one profile of persons who are much more likely than other people to become terrorists in a given political and social environment.

Currently, the problem of discovering and systematically assessing the intentions of a potential terrorist is mainly analyzed in terms of a ‘radicalization process’: a seemingly normal individual is attracted and socialized by others on the Internet or, more often, through direct personal contacts, to embrace a worldview which calls for more or less random attacks against enemies. These radicalized individuals then act either as lone-wolf actors or join a terrorist group at home or abroad. This transition from being an uncommitted but impressionable young man (less often: woman) to developing into a fanatical militant driven by absolutist convictions does not occur overnight. It is a process taking time – usually months, sometimes years. In this period of transition – which is often linked to a form of conversion – persons in the social networks surrounding the person at risk (the vulnerable individual) are supposed to notice changes which can offer detectable early warning signs of violence in the making. These radicalization-driven changes in previously unremarkable individuals can include religion-prescribed clothing, restrictive behaviour toward members of the opposite sex, training in martial arts, a break away from the old circle of ‘friends’, and other observable lifestyle as well as belief alterations. The ability to interpret such changes correctly and then plan interventions to bring an endangered individual back from a path toward violence and self-destruction involves complex analytical skills and tasks. These must include programs that draw together sensitive information obtained from family, friends, colleagues, teachers, and others. In order to intervene effectively along various points in the entire radicalization chain, police and national security officials require validated risk and threat assessment tools to recognize the risk signals of specific pre-attack behaviours. Specialists such as psychologists, community workers, probation officers, and mental health professionals play complementary roles in such interventions.

The present volume is the result of a gathering of academic and professional experts at a NATO Advanced Research Workshop (ARW) at the Harnack conference house of the Max Planck Society in Berlin in late November 2019. Participants were invited from various NATO member and partner countries while a number of researchers were asked to present papers based on their projects for discussion sessions with other participants, in particular, practitioners. These researchers and practitioners have in many cases wrestled for years with the problem of identifying potentially violent individuals in time to intervene.

It was refreshing to notice that new insights were surfacing in this NATO workshop as various assessment instruments for identifying problematic individuals at an early stage were presented by experts. However, these experts also made clear that, due to cultural, religious and other differences, there is no simple solution to identify the relatively few high-risk individuals (i.e., proverbial ‘bad apples’) among the vastly larger population of politically radicalized but not necessarily violent individuals who do not pose a threat. A major policy concern is the risk of false positives, i.e., because of positive scores on multi-risk personality profile assessment instruments an individual can be marked as high risk and yet poses no threat to society. Several experts at the ARW explained that such inaccurate assessments were inherent in existing assessment instruments because motivations are sometimes misinterpreted – something related to the difficulties of separating mental health disorders and individual idiosyncrasies from ideologically motivated individuals. In other words, fundamental validity challenges remain when it comes to methodologies assessing the transition from an “ordinary” person to a dangerous one.

In effect, it is no secret that – until more recently – the profiling of potential terrorists has more often than not been more of an art than a science, even in cases where the well-established structured professional judgment approach has been used. The ambition of the contributors to this volume is to make threat and risk assessments more of a science. The scientific method is characterized by careful observations, the collection of evidence, the formulation of hypotheses via inductive reasoning, the testing of the chosen hypotheses with a larger sample of empirical data, and, subsequently, the use of well-supported hypotheses for theory formation which, ideally, should allow prediction via deduction – in this particular case, allow analysts to identify those individuals with a set of personality- and milieu-characteristics that make them highly likely to engage – or re-engage – in terrorism in the near future.

Developing a validated risk assessment instrument as a reliable prognostic tool to determine harmfulness of a dangerous individual was the key ARW objective. However, due to the considerable array of social and political factors as well as psychological profiles associated with a wide heterogeneity of terrorist types (e.g., homegrown lone-wolf terrorists and foreign fighters, terrorist leaders and terrorist foot soldier, secular terrorists and religious terrorists, male and female terrorists, university-educated and uneducated terrorists, rational and irrational terrorists, suicidal and non-suicidal terrorists) the identification of potentially dangerous persons is a very complicated challenge.

Participants discussed the many obstacles to overcome to construct reliable terrorist risk assessment instruments. Researchers presented data from several NATO member and partner countries that indicated multiple pathways to different types of involvement in terrorism directed against state and society. A major methodological problem of identifying those at risk of becoming violent extremists was the difficulty of extant research designs in obtaining sufficiently large control groups, that is, comparing a sizeable number of convicted terrorists with ordinary members of the general population and then apply the findings to suspected potential terrorists. A common policy theme that emerged was that once a reliable and valid instrument for risk assessment and evidence-based policies has been developed, risk or threat management guided interventions needed to be developed. Such intervention programs have the goal of first detaching a vulnerable individual or an already radicalized extremist from their radical milieu, and then surrounding them with protective factors to prevent a relapse into radicalization and extremism leading to terrorism.

I have focused here on some of the key issues that professional experts at the NATO ARW in Berlin tried to tackle. As a long-time student of terrorism, I witnessed the experts in Berlin wrestling with a truly “wicked” problem – ‘wicked’ in the sense that this problem of identifying potential terrorists is impossible to solve in a way that is simple, universal, and applicable across countries and cultures. I am sure that the readers of the chapters of this volume will share this writer’s appreciation for this practice-oriented book which is likely to become a must read for all those tasked with protecting society from some of its most dangerous members.

Alex P. SCHMID

Director of the Terrorism Research Initiative (TRI)

Corresponding Author, Alex P. Schmid; Email: apschmid@gmail.com. About the author: Alex P. Schmid is the Director of the Terrorism Research Initiative (TRI), a consortium of institutes and individuals who seek to enhance security through collaborative research. Dr. Schmid is Editor-in Chief of ‘Perspective on Terrorism’, an open access online journal. Prof. em. Schmid is also a Research Fellow of the International Centre for Counter-Terrorism in The Hague and editor of the Handbook of Terrorism Prevention and Preparedness (available online at www.icct.nl).