Recruitment models and approaches of Islamist terrorist groups: The cases of al Qaeda and ISIS

Abstract

The recruitment of new members requires delicate secret steps by terrorist and extremist organisations. This vital organisational activity needs to be smart and effective, takes time, and can be discovered by security and intelligence services. This paper shows that recruitment is a flexible multi-tool process able to be smartly adapted to suit the circumstances, needs and character of targeted individuals. We test and confirm the hypothesis that al-Qaeda and ISIS have been flexible in their use of different models and approaches to recruit new members. Our assessment of recruitment activities in the case of selected terrorist cells confirms the same recruiters interchangeably use various recruitment models (Net, Funnel, Infection, Seed Crystal) and recruitment approaches (public and proximate, public and mediated, private and proximate, private and mediated). Such flexibility was not only detected over the longer time period, but also while recruiting members for individual terrorist cells.

Keywords:

• radicalisation
• recruitment
• terrorism
• extremism
• al-Qaeda
• ISIS

1. Introduction

A typical dictionary understanding of a recruit refers to a person who has just joined the armed forces, police or another organisation and is not yet trained or experienced. Terrorist groups also vitally depend on human resources to retain their existing members and obtain new ones. Human resources and human resource management are both key components of terrorist capabilities. New members bring fresh enthusiasm and motivation, while adding to existing experience, knowledge and situational awareness. They are generally very motivated and can be used to perpetrate new terrorist attacks or other risky operations. The recruitment of new members for the organisation is a critical entry process for all terrorist groups. No one was born a terrorist.

A key research focal point in the literature is the broader process of radicalisation, with less academic attention paid to understanding how the recruitment process really works and how to stop it. The radicalisation of individuals and groups goes hand in hand and successful recruitment can occur in the context of a broader process of radicalisation. As Neumann and Rogers (2007; also see Prezelj et al., 2021; Taarnby, 2006), recruitment entails practical steps in joining a terrorist organisation, while radicalisation refers to changes in perceptions, values and behaviour. Davies et al. (2015) understand radicalisation simply as an introduction to recruiting while Van Engeland and Rudolph (2008) stress that the militant jihadist ideology of al-Qaeda itself could be an attractive factor and an inspiration in the recruitment of new members. All of the internal factors of radicalisation defined by Ranstorp (2010, pp. 4–7)¹ essentially play a role in recruitment. Ranstorp also showed that in some cases recruitment may even precede radicalisation, not vice versa. This complex relationship puts several current models of radicalisation into question.

Korteweg et al. (2010, pp. 33–35) stress that due to increased control by intelligence services the recruitment environment has changed lately towards less visible recruitment activities, less detectable training events and looser network forms of organisation. Mujahedin radicals can still easily find suitable young candidates in orthodox mosques, Islamic cultural centres, and prisons. Sageman (2004, pp. 121–122) viewed recruitment as a process of joining through which an organisational insider obtains a new person to work for the organisation. This process is somewhat similar to the recruitment of secret agents by intelligence services (by including clandestine spotting, assessing, developing and formally pitching the agent). Still, his impression was that al-Qaeda recruitment was more a bottom-up than a top-down activity given the large number of eager candidates. Joining in jihad looked more like applying at a highly selective college for which most candidates are not accepted. This might not be surprising since joining a terrorist group requires a level of commitment most people find difficult to comprehend (see McCauley & Moskalenko, 2011, p. 81). Finally, Combs (1997, p. 126) noted that screening and selection of potential recruits is not just an essential skill of successful terrorist groups, but that most terrorists are also trained in recruitment techniques as their groups depend upon transfusions of new members. The above-mentioned facts make recruitment a rational and strategically based process of searching for and identifying suitable individuals, assessing, and finally obtaining their consent to join the group (Mulcahy et al., 2013, p. 9).

A considerable amount of recent scholarly literature on recruitment focuses on the impact of communication technologies like the Internet, social media, and messaging applications. In this regard, Weimann (2016; see also Meleagrou-Hitchens & Hughes, 2021; Tonnessen, 2017; West, 2016) studied how extremist organisations utilise social media (Facebook, Twitter, YouTube) and messaging applications (WhatsApp, Kik) to identify and recruit new members, while other studies explored how ISIS’ online propaganda narratives attract new members (Baele et al., 2020; Lakomy, 2019; Mahood & Rane, 2017). Some studies also link the increased use of social media to the rise of lone wolf terrorism (Hamm & Spaaij, 2017; Jones, 2017). This paper, however, does not include this phenomenon in the analysis as lone wolf actors are never formally recruited into a terrorist group itself.

On the other hand, certain authors still recognise physical places, such as prisons and mosques (Kanol, 2022; Rushchenko, 2019), as well as NGOs (Prezelj & Kocjancic, 2020) as relevant venues for recruitment. Since these studies analyse the contexts of recruitment separately, there is a need to study the recruitment process more holistically. The existing literature is also limited by the number of comparative case studies since they mostly adopt a single-case study design.

A research model that addresses both top-down and bottom-up recruitment approaches as well as different contexts of recruitment is presented in the work of Gerwehr and Daly (2006). In a very relevant RAND report on the structure of the recruitment process, they defined four models (Net, Funnel, Infection, Seed Crystal) and various approaches to recruitment according to the use of persuasive instruments (public vs. private forums and proximate vs. mediated contacts). To our knowledge, this is the most sophisticated and holistic model of the recruitment process that exists in the literature. In this paper, we applied this research model to the case of al-Qaeda and ISIS. There have, however, been notable developments in the field of digital communication technology and significant alterations to the recruitment process (e.g., see Jones, 2017; Weimann, 2016) since the two authors mentioned above developed these models and approaches back in 2006. We have accordingly supplemented Gerwehr and Daly’s work with more contemporary research on terrorists’ use of the Internet and social media for recruitment purposes.

The goal of this paper is to assess which recruitment models and approaches have been used by al-Qaeda and ISIS and how they were used. Some researchers (see Choi et al., 2018; Nacos, 2016) stress the difference between al Qaeda and ISIS when it comes to their recruitment processes. This difference is also rooted in the fact that these two terrorist groups were most active in the West in distinct time periods. Yayla (2021) further argued that while terrorist organizations have historically used varying tactics to recruit new members, often based on their ideologies, locations and objectives, there are also several similarities because they learn from each other. Based on this this complex set of circumstances, we hypothesise that al-Qaeda and ISIS have been flexibly relying on different models and approaches to recruit new members. This means that various recruitment models (like the Net, Funnel, Infection or Seed Crystal ones) and recruitment approaches (like the public and proximate, public and mediated, private and proximate, or private and mediated ones) might be used interchangeably not only over a longer time period, but also when recruiting members of specific terrorist cells and even individual persons. Modern terrorist recruitment should thus be seen as an adaptable/flexible multi-tool process that can lead to new terrorist attacks.

This paper first presents and conceptually deepens the existing models and approaches concerning recruitment by Gerwehr and Daly. In the empirical part, we analyse recruitment before and after 9/11 by al-Qaeda with a specific focus on the “Hamburg cell”, while for ISIS we analyse recruitment between 2014 and 2018 with a spotlight on a Brussels terrorist cell. Both cases are analysed on a general organisational level and also the more specific individual level of recruitment for particular terrorist cells. Both terrorist organisations have been weakened, yet remain a threat. Al-Qaeda recently expressed its interest in carrying out terrorist attacks in the West (Europol, 2020), while ISIS is spreading its influence in West Africa, some parts of the Middle East and East Asia (Cordesman, 2020; Gartenstein-Ross et al., 2020; Paquette et al., 2020). The November 2020 terrorist attack in Vienna, Austria, by a 20-year-old individual that killed 4 people and wounded 22 was also claimed by ISIS.

2. Recruitment: models and approaches

2.1. Recruitment models

Gerwehr and Daly (2006, pp. 74–75) are clear in stating that effective recruitment pitches should be tailored to the audience and its cultural, social and historical context. Accordingly, there can be no single uniform recruitment process for a terrorist group. There are as many recruitment processes as there are distinct regions and nodes in which groups operate. Recruitment techniques involve some similarities and some differences. Based on this evaluation and certain existing common patterns, the mentioned authors developed several models and approaches to recruitment: the Net, Funnel, Infection and Seed Crystal ones.

2.1.1. The net model

This recruitment model can be applied to a target group that is homogenous and where group members are ready to begin the recruitment process. The recruitment pitch thus does not need to be separately tailored to each individual but can be delivered in a more general manner. Some group members might react negatively to the recruitment pitch and exit the recruitment process while others who respond positively progress to the next recruitment level. An example of where the Net Model is likely applied is a mosque led by a radical imam² (Gerwehr & Daly, 2006, pp. 76–77). Although since 9/11 there has been a decline in terrorist recruitment in Western mosques due to increased surveillance efforts, they remain fertile locations for identifying various talents (Neumann & Rogers, 2007). Further, the Internet offers various virtual spaces, such as public forums, blogs, chat rooms, and social media groups, in which ideas of radical Islam are exchanged and user groups are homogenous and groomed for the recruitment pitch (see Meleagrou-Hitchens et al., 2017, pp. 1236–1242).

2.1.2. The funnel model

When the target group is ready for the recruitment process but does not yet possess the required identity and motivation, a recruiter can employ a step-by-step approach. The Funnel Model offers such a transformation process whereby recruits must demonstrate their desire to become a member of a terrorist organisation. They can do this by showing their knowledge of radical Islam or in violent actions. The rigorous process means some recruits drop out while those whose transformation is successful become a member of the terrorist organisation (Gerwehr & Daly, 2006, pp. 77–78). An example is when potential recruits go through rigorous training and further indoctrination in training camps (see Gerwehr and Daly, pp. 74, 75, 83; Reynolds, 2016, p. 42). This is where, according to Yayla’s (2021, pp. 404–405) eight-stage recruitment process, candidates are assigned to different parts of the organization. And as Jenkins (2007, p. 2) notes while writing about al Qaeda, candidates were assigned to special tasks only after they had undergone the training process in the camps.

The Internet has enabled terrorist organisations to move some of these processes online in the form of decentralised virtual training camps, providing manuals for light weapons, military tactics, communications, security, electronics, and explosives (Stenersen, 2008, p. 216).

This recruitment model may be compared to the fourth floor in Moghaddam’s staircase model (Moghaddam, 2005, p. 162). It is on this floor that the recruitment process is concluded when recruits start to see the world in black-and-white, in terms of “us vs. them” and also consider terrorist organisations to be legitimate.

2.1.3. The infection model

Some target groups cannot be penetrated from the outside, leaving recruitment from the inside as the only possible way. Terrorist groups can infiltrate a recruiter into a closed group where the recruitment is carried out in person, typically one-to-one. Here, the recruitment pitch must be customised to suit the needs and values of the receiver. Next, a potential recruit who positively responds to the recruitment pitch spreads such messages and “infects” other members of the group (Gerwehr & Daly, 2006, pp. 78–79).

Della Porta (2006, p. 167) stressed it is rare for individuals to decide to join extremist groups solely on their own. This decision is most often influenced by their friends who are already members of an extremist group.

An example of a location featuring such dynamics nowadays in Western countries is prisons. Namely, some prisoners are already inclined towards violent actions, which simplifies the recruitment process (Rushchenko, 2019, p. 302). Burke et al. (2021, p. 238) notes that radicalisation and recruitment are both more easily carried out in prisons than in civil society given the difficulty of prison guards detecting such efforts and the closed nature of prison community. Conversations are held in person on an individual level and in secrecy. Such an approach enables the recruiter to discover grudges, needs and miseries in order to appropriately craft the recruitment pitch. While most prisoners do not hold extremist views, they may acquire such beliefs as a result of such radicalisation and recruitment efforts (Mulcahy et al., 2013; also see, p. 8; Neumann & Rogers, 2007, pp. 42–43).

2.1.4. The seed crystal model

Certain target groups are geographically too distant to allow the infiltration of a recruiter, nor can they easily be subject to media propaganda operations. Most of these groups are located in the West (USA and Europe). In these cases, terrorist groups may develop self-recruitment capabilities, indicating a bottom-up recruitment process. Over time, particular individuals express a willingness to become a member, usually through online forums, specific websites or simply through social media. Individuals who actively express their inclination towards the terrorist group are then contacted by a recruiter. Communication between the recruiter and potential recruit proceeds online but in private channels (Gerwehr & Daly, 2006, p. 79).

An example of the Seed Crystal Model is recruitment via the Internet and social media, where recruiters can identify, background check, and select possible recruits. In the last decade, many jihadi groups and individuals have used mainstream social media platforms, such as Twitter, Facebook, Tumblr, Instagram and YouTube, to spread their message (Jones, 2017, p. 321; Klausen, 2015, p. 1). Initially, the content is promoted online where information-seeking behaviour is likely to lead to an interaction between those seeking information and the recruiters. Once recruiters have identified individuals who respond positively to the propaganda material, they can establish contact with them and move the conversation into private channels (Reynolds, 2016, p. 40). This is where recruitment in the Seed Crystal model concludes, and the process of the Funnel model begins. The communication continues via private communication channels (Weimann, 2016, pp. 81–82) provided by applications like Telegram, Kik and Sure spot that use encryption (West, 2016, pp. 22–23). Potential recruits thus identified are then constantly provided with additional propaganda material, religious beliefs, and training manuals (Weimann, 2016, pp. 81–82).

Interestingly, the use of this model has also affected future lone wolf terrorists inspired by the ideology and propaganda disseminated by recruiting organizations but never actually recruited by them. The difference between recruited people and lone wolves is that their decision to become active is not made in the direct interaction process with the recruiter. One example of this case is the terrorist attack in London on 7 July 2005. The attack was carried out by four militant jihadists who were not members of the al-Qaeda terrorist group and were acting alone (Bennetto & Herbert, 2005; Hamm & Spaaij, 2017, p. 178; Townsend, 2006) even though the group’s leader, Mohammed Siddique Khan, had travelled to Afghanistan where he may have made contact with al-Qaeda and received training from a senior member of al-Qaeda (evidence regarding this remains unclear) (McGrory et al., 2007; O’Neill et al., 2007).

2.2. Approaches to recruitment

Gerwehr and Daly (2006, pp. 80–84) saw recruitment communication as having two main dimensions: public vs. private, and proximate vs. mediated. Combining these two dimensions, they define four approaches to recruitment as described below.

2.2.1. Public and proximate approach

In this approach, the recruitment process occurs in public spaces with personal contact. Possible locations are prisons, mosques, refugee camps, festivals, and demonstrations. This recruitment approach thrives in environments with deficient legislation or lacking in political sensitivity to terrorist issues (Gerwehr & Daly, 2006, pp. 81–82).

2.2.2. Public and mediated approach

When it is impossible for a terrorist group to make personal contact with its target group, it makes use of a range of public tools (Gerwehr & Daly, 2006, p. 82). While in the past terrorist groups had to rely on intermediary links such as traditional media to spread their messages, these days this communication process is made easier by social networks, which allow terrorist groups to deliver information and propaganda material directly to individuals (Lieberman, 2017, p. 101). While Gerwehr and Daly (2006, p. 82) contend the public and mediated approach “sacrifices the persuasive power of more intimate, tailored appeals”, recent studies (see Weimann, 2016) indicate that terrorist groups are increasingly using the Internet to target specific sub-populations as well, which requires them to tailor their message to certain audiences.

2.2.3. Private and proximate approach

With this approach, recruitment occurs behind the scenes, out of the public eye. It is based on a personal approach so the recruitment pitch can be tweaked to meet the specific needs of an individual or smaller group (Gerwehr & Daly, 2006, p. 82). A crucial element of the recruitment process is the resocialisation of potential recruits. This includes adopting the terrorist organisation’s system of symbols, values, beliefs and patterns of behaviour. The most effective way to achieve resocialisation is via the proximate influence of friends, family, teachers, imams or through indoctrination (Arena & Arrigo, 2005, p. 495).

2.2.4. Private and mediated approach

Recruiters can engage in the recruitment process through private channels without personal contact. This may be done by privately printing propaganda literature and manuals and their subsequent covert distribution to the wider public, or online via password-protected websites and encrypted communication applications (Gerwehr & Daly, 2006, p. 83). This represents a concern in counter-terrorism efforts because a recruitment process based on the use of such applications cannot be intercepted (Graham, 2016, p. 20).

The above classifications of recruitment models and approaches are somewhat intertwined. To further clarify the concepts and enable us to explore our empirical cases, we prepared a table that shows the interconnections of the discussed models and approaches (see Table 1).

Table 1. Classification of recruitment models by types of approaches (based on graphs in Gerwehr & Daly, 2006)

		Forum
		Proximate	Mediated
Channel	Private	Infection model private apartments (one-to-one) friends and family Funnel model training camps	Funnel model encrypted messaging applications private chat rooms password-protected websites privately printed propaganda literature
	Public	Net model mosques private apartments (presence of a group) festivals Infection model prisons refugee camps private libraries universities and schools city streets	Net model online public forums blogs chat rooms social media groups Seed Crystal model propaganda videos online (free access) propaganda literature in forums TV and radio stations newspapers social media platforms

3. Methodology

The decision to select al-Qaeda and ISIS as the two cases was based on the following criteria. First, they are the biggest and most global terrorist organisations that have also caused the greatest casualties (see Global Terrorism Index, 2023, p. 2; Stanford, 2019). Second, both cases represent terrorist groups with religious motivations and whose members are fundamentalist militant jihadists and Islamic extremists. Third, each terrorist group has organised and perpetrated major terrorist attacks in the West. Fourth, these two terrorist groups established terror cells in Europe, which allows us to also compare the recruitment processes on a cell level. Despite some differences between the cases (level of brutality, ability to take territory, etc.), the similarities identified above provide an adequate base or sufficiently “similar systems design” (see Rihoux & Ragin, 2009, pp. 21–22) for comparative analysis. The selection of the two cases creates sufficient representativeness, incorporating the elements of “unusual” and “typical” cases (see Ragin, 1994, p. 85), and offer the greatest opportunity to learn in the present time (see Stake, 1994, p. 243). Although a comparison of recruitment to organizations from different milieus (e.g., right-wing organizations) may well add variety to the results, we decided to focus on two more typical cases, sharing the roots of the extremist Sunni interpretation of reality without broad ideological disparities. Both organizations’ cells also operated in Western environments, allowing us to delve into more subtle recruitment differences and related tactical variations. Comparative results along these lines hold greater relevance for European counter-terrorism policy. This also explains why we chose to compare the recruitment processes of Hamburg and Brussels terrorist cells, not of al-Qaeda’s and ISIS’ affiliated organizations. The central terrorist organizations and their cells are also trendsetters in terms of recruitment for other extremist groups, including affiliated ones.This paper followed the case study analysis process proposed by George and Bennet (2005). They present a three-phased design that includes: (1) designing case study research; (2) carrying out the case study; and (3) drawing the implications for theory of the case findings. After specifying the research problem and related objectives in the first phase, we developed a hypothesis and selected the variables from key components of Gerwehr and Daly’s research model; namely, the recruitment models (Net, Funnel, Infection, Seed Crystal) and approaches (public-proximate, public-mediated, private-proximate, private-mediated). As a variance in variables, we predicted that recruitment to both terrorist organisations as well as their cells was carried out according to all models and approaches. Due to the rise of social media, encrypted messaging applications, and more efficient counterterrorism measures, we also expected a bigger share of mediated approaches in newer cases. This also likely leads to recruiting being more in line with the Seed Crystal and Funnel models. Third, we selected the cases based on the criteria described above. Fourth, to acquire deep knowledge of both cases, qualitative data were collected from different primary and secondary sources that include relevant information on al-Qaeda’s and ISIS’ members, such as scientific articles, official documents and reports, news articles, and pertinent websites. In order to analyse the recruitment processes for selected terrorist cells, we constructed individual members’ biographical backgrounds before analysing the recruitment models and approaches based on these backgrounds. The data for analysing the recruitment process for the Hamburg cell were largely gathered from the 9/11 Commission Report as well as from different news articles, whereas the data on the Brussels cell members primarily came from different news articles and relevant websites.

Pejorative use of the term “Islamist” can frequently lead to unnecessary negative generalizations in the literature and practice (see Al-Kassimi, 2021a, pp. 11–12). This term normally refers to individual or group adherents of Islamism or political Islam who are dissatisfied with the degree of Islamization of their societies or foreign countries and want to replace the existing political system(s) with the Islamic State (see Woltering, 2002, p. 1133). However, Islamism is characterized by a wide variety of activities with fluid transitions between fundamentalism and political activism as well as between nonviolent and militant extremism or terrorism (Hummel & Rieck, 2020, p. 89). In this paper, we have combined this term with the term “extremism” or “terrorism” to reflect the cases when extreme violent methods are used to achieve the above mentioned goals. Islamist terrorist groups also typically use the concept of jihad to employ violence against their targets. In this paper, the term “jihadist” refers to individuals or groups that misuse the concept of jihad (as an internal and external struggle of good against evil) as a central religious duty to violently fight the near and far enemy (the “vassal” regimes in Muslim countries and the West) (Hummel & Rieck, 2020, p. 89). This broad range of approaches is evident in Salafi ideology, where “the purists” clearly avoid political activism and violence, “the activists” use strong rhetoric against the enemy, actively engage in local societal issues, and forbid participation in democratic processes, while “the militants” or “Salafi jihadists” carry out armed combat as a religious duty, excommunicate non-Salafis, justify violence, etc (see Ranstorp, n.d.., pp. 7–8).

4. Organisational level of recruitment

4.1. Recruitment by al-Qaeda

While the 9/11 terrorist attacks against the United States in 2001 were not the first to be successfully carried out by al-Qaeda in that country (Forest, 2012, pp. 247–250), they have been the most impactful ones. Those terrorist attacks are the primary reason the USA and Europe have strengthened their counterterrorism security measures. This makes it reasonable to assume that al-Qaeda has adapted to these measures, even when recruiting new members. Accordingly, we divided Al-Qaeda’s recruitment efforts into two timelines: recruitment before 9/11 2001, and recruitment since then.

4.1.1. Recruitment before 9/11 2001

Prior to 11 September 2001, the security environments in the USA and Europe were less cognisant of the terrorist threat. Radical imams could thus spread their messages among those attending mosques, Muslim religious schools, and charities. Most of the propaganda material was distributed in the forms of audio and video tapes of imams delivering fiery sermons (McDermott, 2006, p. 3). The most active mosques in Europe were the Finsbury Park Mosque in London, the Islamic Cultural Centre in Milan, the Abu Bakr Mosque in Madrid and the Al-Quds Mosque in Hamburg. Apart from being a place where young radical Muslims could express their feelings and opinions, in the 1990s mosques also served as a gateway for terrorist camps in Afghanistan and Pakistan, where training and ideological indoctrination took place (Taarnby, 2006, pp. 7, 10–40).

Through the training process, potential recruits became less resistant to acts of violence and acquired paramilitary skills and knowledge, while the cruel life in the camps strengthened the bonds among them. Based on the training results, recruits were later assigned a role in the mission for which they were best suited. Radicalisation and recruitment processes were also conducted in public libraries, universities, and other Muslim organisations. Along with mosques, these were the physical locations where recruitment efforts were most often made (Wiktorowicz, 2005, p. 118).

Prior to 9/11, al-Qaeda appears to have primarily recruited new members on the basis of the Net Model and Funnel Model. The target group was mainly individuals who already held Islamic beliefs and already had a grudge against the West, its values and institutions. If potential recruits showed interest in joining the terrorist group, the recruitment process continued according to the Funnel Model. Recruiters organised trips to Afghanistan and Pakistan where prospective recruits were trained and indoctrinated.

The most common combinations of approaches to recruitment were public-proximate and private-proximate. The low perception of the terrorist threat in the USA and Europe before 9/11 meant the authorities and law enforcement paid little attention to Muslim public spaces. Yet, these provided excellent conditions for recruiting new members as recruiters could freely make new contacts and disseminate al-Qaeda’s militant jihadist propaganda via leaflets and video and audio tapes.

4.1.2. Recruitment after 9/11 2001

Following 9/11, al-Qaeda was forced to adapt to the new security environments of the Western world. The new security measures made recruiting in public spaces a risky endeavour. In addition, the USA’s invasion of Afghanistan led to a large number of destroyed training camps, forcing al-Qaeda to search for new recruitment tools. One of these was the Internet. Through cyberspace, propaganda materials could be disseminated more quickly and easily while the Internet proved to be a decent substitute for the training camps that had been destroyed (Moran, 2004).

However, while al-Qaeda was successful in attracting new members through online recruitment, these members were not specialised. Although the Internet is an excellent recruitment tool, it is no substitute for formal, face-to-face training. As a result, al-Qaeda to some degree still relied on recruitment in radical mosques. Outside of the USA and Europe, Islamic schools also became fertile recruiting grounds due to the ability to spread extremist Islamic ideology through their education systems (Bloom, 2017, pp. 612–615). The terrorist group also retained some of the physical approaches by distributing training manuals, such as the Encyclopaedia of Jihad, in the form of pamphlets and CDs at the face-to-face meetings (Moran, 2004).

Since 9/11, al-Qaeda has conducted its recruitment efforts using a variety of models. Recruitment in mosques continues, indicating the Net Model. The Funnel Model has been applied in cyberspace, using online forums and other extremist jihadist websites to publish manuals (Jihadist Use of Social Media, 2011, pp. 13–25), while the Infection Model is present in prisons (see Cuthbertson, 2004, p. 15). Wider use of the Internet has seen recruitment using the Seed Crystal Model become more common. Further, online extremist propaganda has enabled self-radicalisation and self-recruitment (Jenkins, 2007, p. 3).³

With the lost training camps in Afghanistan, al-Qaeda had also lost some private-proximate channels that were available before 9/11. Today, the terrorist group relies on modern technologies like password-protected websites and online forums with limited access (Aly et al., 2017, p. 5; Weimann, 2004, p. 10). This type of recruitment is private-mediated, meaning the recruitment process occurs beyond the reach of the authorities. Since 9/11, al-Qaeda has also been using social media to recruit new members (see Hearing before the Committee on Homeland Security and Governmental Affairs United States Senate, 2016, pp. 14–15), which falls within the public-mediated approach.

4.2. Recruitment by the Islamic state

The Islamic State is well known for the territory it occupied in Syria and Iraq between 2014 and 2018, and for its ability to attract large numbers of foreign fighters from the West. The terrorist group has been successful not only in Europe, but also in Asia and Australia (Torok, 2015). Despite ISIS’s territorial losses in Syria and Iraq, Europol (2020) still considers it a threat to security, particularly following 2019 attacks in Sri Lanka on Easter Sunday.

In 2018, ISIS had around 30,000 members (‘ISIS has’, 2018. To recruit such a mass of people, ISIS exploited two main phenomena. The first was the 2015 refugee crisis in Europe (Thomas, 2015). The failures to integrate the refugees into the European labour market along with the waves of far-right activity and Islamophobia that arose during the refugee crisis produced a considerable pool of potential recruits. The second phenomenon was the digitalisation of Western society, which has made the Internet a successful recruitment tool also for the second generation of immigrant families and others. Even though al-Qaeda was using the Internet for similar purposes before ISIS, the latter’s timing was better. Before 2001, al-Qaeda mainly relied on websites, online chat rooms, cybercafes, and online bulletin boards to spread its propaganda and identify potential recruits (Weimann, 2008, pp. 62–63), together with satellite telephones for clandestine communication (Weimann, 2004, p. 8). However, terrorist groups were only able to use the Internet to attract and recruit new members any more effectively following the appearance of social networking sites (the Facebook domain name was registered in 2004, YouTube in 2005, Twitter in 2006, and Instagram in 2010) and messaging applications (WhatsApp was developed in 2009, Kik in 2010, and Telegram in 2013) (Klausen, 2015, p. 1). While during the 1990s al-Qaeda only had a few hundred active supporters, the revolution in information technology allowed ISIS to connect up with a vast population of potential recruits (Neumann, 2016, pp. 26–27).

4.2.1. Recruitment between 2014 and 2018

Between 2014 and 2018, ISIS recruited new members using all four recruitment models. However, some models were used more frequently than others. Many new members became acquainted with ISIS’ interpretation of Islam and its strategic long-term goals through propaganda that was circulating on the Internet. Individuals who responded positively to the videos, pictures, forum discussions or texts sought opportunities to join the terrorist group. This propaganda proved very effective, especially because ISIS managed to recruit most of its members online.⁴

Due to strict surveillance in Western Europe and the USA, the Net Model has seen less use. While there are some instances of individuals being recruited according to this model (see ‘Mosques in Switzerland Proven to Have Ties to ISIS, 2019), such recruitment was more common in the Western Balkans and the Middle East. For example, in a certain Albanian mosque Imam Bujar Hysa managed to recruit 70 members who later became foreign fighters (Ristic, 2016, p. 4).

The Infection Model was detected in some European prisons where imprisoned foreign fighters and radical imams continued their efforts to radicalise and recruit other prisoners (Reynolds, 2016, p. 41). In this case, the recruitment pitch could be tailored to the needs and values of an individual prisoner.

The Funnel Model was applied in both physical and cyberspace. In the first case, potential recruits travelled to ISIS’ training camps in Syria and Iraq where they underwent rigorous training and indoctrination. The Funnel Model in cyberspace can be identified once the recruitment process continued by using messaging applications that rely on encryption. Here, the recruitment continued in private between the recruiter and potential recruit. The recruiter then began to demand more demanding tasks from the recruit, providing him with additional propaganda literature while suggesting that he isolate himself from his friends and family (Speckhard & Ellenberg, 2020).

Between 2014 and 2018, the widespread use of the Internet as a recruitment tool meant the most common approaches to recruitment were public-mediated and private-mediated. The former begins with the dissemination of propaganda materials through the mass media and social networks. Potential recruits were identified by ISIS’ recruiters and the conversation between the two continued via encrypted messaging applications, namely, the private-mediated approach.

Despite occurring less frequently, the other two approaches to recruitment should not be ignored. The public-proximate and private-proximate approaches have both been used in Europe, albeit to a smaller extent due to the vigilant surveillance. There are also some cases of ISIS members having been recruited in mosques, prisons, football grounds, and universities (see above). Recruitment efforts at these locations fall within the public-proximate approach. The recruitment process then continued by making friends and holding private meetings, which refers to the private-proximate approach.

5. Individual level of recruitment

5.1. The Hamburg terrorist cell

On 11 September 2001, the news of a terrorist attack in the USA spread around the world. The events on that day have been called the deadliest terrorist attacks in history, killing 2,996 people and injuring 6,000. Responsibility for the attacks was claimed by al-Qaeda, more specifically its terrorist cell in Hamburg, later known as the “Hamburg cell”. Four members were the core of this cell: Mohamed Atta, Marwan al-Shehhi, Ramzi bin al-Shibh and Ziad Jarrah. We should also mention Mohammed Haydar Zammar, who played a major role in recruiting the four individuals into the cell through his activities at the Al-Quds Mosque in Hamburg.

All four members of the cell came from well-off families and had moved to Hamburg, Germany in order to pursue a higher education. At one point Atta, al-Shehhi and Jarrah all studied at the Technical University of Hamburg-Harburg, following different degrees in engineering (National Commission on Terrorist Attacks upon the United States [NCTAUS], 2004, pp. 160–167). Since they were educated, they were entrusted with more complicated and secret tasks like flying planes into key targets. For this purpose, Atta, al-Shehhi and Jarrah travelled to the USA in 2000 to train as pilots and obtain their licences, while bin-al-Shibh’s visa application was declined and he thus stayed in Germany (Blaauw-Wolf, 2004, p. 798). This also correlates with the study by Gambetta and Hertog (2009) who explained that at that time most Islamic radicals held an engineering education and a rather mechanical view of the ideal society. In addition, while neither member showed signs of extremism at the time they had immigrated to Germany, the focal location in their recruitment process appears to be the Al-Quds Mosque (NCTAUS, 2004 −167;, pp. 160; Finn, 2002).

The analysed data show the four members were self-radicalised through propaganda literature, the mass media, and the Internet (see NCTAUS, 2004, pp. 160–167). Given that all members came into contact with radical Islam on their own, without any interference from the recruiters, the Seed Crystal Model appears to apply to the first step in the recruitment process. We should note that some members of the Hamburg cell already knew each other before coming into physical contact with each other in that city, while the practical recruitment steps to become a cell member only started when they were living together in the Hamburg apartment (NCTAUS, 2004, pp. 160–167).

The Al-Quds Mosque in Hamburg served as an ideal place to conduct recruitment according to the Net Model. Radical imams were able to spread their messages among those in attendance without the interference of law enforcement. Regular mosque visitors included the four core members of the Hamburg cell, who were approached by Zammar on several occasions. Another location that indicates application of the Net Model is the apartment of the four members. This location was ideal for holding larger meetings to which other radicalised Muslims were invited and where Zammar could safely distribute propaganda pamphlets and continue the recruitment process. At these private meetings, Zammar also urged participants to travel to Afghanistan to train at al-Qaeda camps. This trip was also taken by all four of the cell’s core members to further train and indoctrinate themselves (Frantz et al., 2002), which points to the Funnel Model of recruitment.

Analysis of the recruitment of the four core Hamburg cell members shows use of three main approaches. Al-Qaeda’s propaganda, which was then spread via the Internet and other media, attracted the four recruits and enabled them to radicalise themselves. This indicates the public-mediated approach. The recruitment efforts at the Al-Quds Mosque, where the four members heard radical speeches and made contact with Zammar, point to the public-proximate approach. The third approach—private-proximate—can be identified at two locations: the private apartment of the four members where meetings were held, and al-Qaeda’s training camps in Afghanistan where recruits completed training and underwent further indoctrination processes. Table 2 shows the combination of models and approaches used with respect to the key recruits to this cell.

Table 2. Models and approaches to recruitment of members of the Hamburg cell

Members	Recruitment model	Approach to recruitment	Circumstances
Mohammed Atta	Seed crystal model	Public-mediated	Fliers, brochures, mass media
	Net model	Public-proximate	The Al Quds Mosque and the cell members’ apartment
	Funnel model	Private-proximate	Training and indoctrination in al-Qaeda’s camps in Afghanistan
Marwan al-Shehhi	Seed crystal model	Public-mediated	Fliers, brochures, mass media
	Net model	Public-proximate	The Al Quds Mosque and the cell members’ apartment
	Funnel model	Private-proximate	Training and indoctrination in al-Qaeda’s camps in Afghanistan
Ramzi bin al-Shibh	Seed crystal model	Public-mediated	Fliers, brochures, mass media
	Infection model	Private-proximate	Influence of Atta
	Net model	Public-proximate	The Al Quds Mosque and the cell members’ apartment
	Funnel model	Private-proximate	Training and indoctrination in al-Qaeda’s camps in Afghanistan
Ziad Jarrah	Seed crystal model	Public-mediated	Fliers, brochures, mass media
	Net model	Public-proximate	The Al Quds Mosque and the cell members’ apartment
	Funnel model	Private-proximate	Training and indoctrination in al-Qaeda’s camps in Afghanistan

5.2. The Brussels terrorist cell

A terrorist cell in Brussels was responsible for the Paris terrorist attacks on 13 November 2015 and the terrorist attacks in Brussels on 22 March 2016. The cell was most active between 2014 and 2018 and included 57 members at its peak (Bolton, 2015). Given the scarcity of information about members of the “Brussels cell”, the paper focuses on the three most prominent members for whom the most information could be gathered (Abdelhamid Abaaoud, Salah Abdeslam and Samy Amimour) and Khalid Zerkani, who was ISIS’ main recruiter for the Brussels cell. Although ISIS is known for its online recruitment, only one member of the Brussels cell we studied was radicalised and recruited in cyberspace, whereas the other two members were recruited in physical space using a personal approach.

All three studied cell members were young (below 30 years of age) and second-generation immigrants with practically no religious education. The trajectory of their conversion was rapid and often in the framework of a group of friends or over the Internet rather than in the setting of a mosque (Burgis, 2015), as happened with the Hamburg cell members. Abaaoud and Abdeslam had also often been involved in petty crime (Faiola & Mekhennet, 2015), while Amimour had expressed his dissatisfaction with living in France as a Muslim (Hinnant, 2016). This finding coincides with the observation by Rekawek et al. (2019, p. 10) who claimed that members of ISIS’ terrorist cell “employed individuals with criminal know-how to, e.g., obtain fake ID cards that allowed them to remain undetected for a prolonged period of time”.

The recruitment in physical space was mainly conducted by Khalid Zerkani, who approached potential recruits individually on the streets of the Brussels suburb of Molenbeek. This suburb offered great possibilities for terrorist recruitment due to its crime saturation (Higgins & De Freytas-Tamura, 2016). Potential recruits thus had greater tolerance for violent acts, which is one of the characteristics of terrorists. We can detect the Infection Model because Zerkani did not target crowds but addressed individuals on a personal level.

Abdelhamid Abaaoud and Salah Abdeslam were also recruited in line with the Infection Model. The former began his radicalisation process in Saint Gilles prison, where he developed a relationship with other radical Muslim inmates, while his recruitment into the terrorist cell commenced once Zerkani approached him on the streets of Molenbeek (Higgins, 2015). Abdeslam, on the other hand, was recruited by Abaaoud after he had returned from Syria in 2014 (Davis, 2016). Abaaoud and Abdeslam knew each other since children and were frequently in trouble for petty theft (Graham, 2016). We assume that these circumstances allowed Abaaoud to exert an influence over his friend Abdeslam and recruit him for the cell.

Samy Amimour, the third member being analysed, was radicalised and recruited according to the Seed Crystal Model. He was, according to his schoolmate, radicalised on the Internet, where he came under the influence of ISIS propaganda by browsing websites and social networks filled with propaganda videos, texts and images (Burgis, 2015). Thus, in Amimour’s case, we can also identify self-radicalisation and self-recruitment. Later, in 2014, he travelled to Syria to one of ISIS’ terrorist camps (ibid.). How he met Abaaoud and was recruited into the Brussels terrorist cell remains unknown. Still, we can speculate that their paths crossed in Syria, since their travel dates overlap. Except in the case of Abdeslam, we can also identify the Funnel Model based on the trip to ISIS’ terrorist camps in Syria.

The aforementioned circumstances permit us to confirm that all four approaches were used for recruitment with regard to the Brussels cell. The public-proximate approach was employed by Zerkani when recruiting individuals on the streets of Molenbeek and in Saint Gilles prison where Abaaoud became radicalised. The public-mediated approach is observed in the case of Amimour’s online self-recruitment process. Assuming that the conversation between him and the recruiter moved over to private communication channels that use encrypted messaging applications, we can also identify the private-mediated approach. Finally, the private-proximate approach is seen with respect to the training of Abaaoud and Amimour in ISIS’ camps in Iraq and Syria, whereas the same approach (but a different model) was used when Abdeslam was recruited into the cell through his friendship with Abaaoud (see Table 3).

Table 3. Models and approaches to recruitment of members of the Brussels cell

Member	Recruitment model	Approach to recruitment	Circumstances
Abdelhamid Abaaoud	Infection model	Public-proximate	Radicalised in Saint Gilles prison, recruited into the cell on the streets of Molembeek by Khalid Zerkani
	Funnel model	Private-proximate	Training and indoctrination in ISIS’ camps in Syria and Iraq
Salah Abdeslam	Infection model	Private-proximate	Friendship with Abdulhamid Abaaoud
Samy Amimour	Seed crystal model	Public-mediated	ISIS’ propaganda on websites and social media
	Funnel model	Private-mediated (speculative)	Encrypted messaging applications (speculative)
	Funnel model	Private-proximate	Training and indoctrination in ISIS’ camps in Syria and Iraq

6. Conclusion

The recruitment of new members requires terrorist and extremist organisations to take delicate and secret steps. While on one hand this activity is vital for these organisations, on the other many attempts are not successful and recruiters/targets can be detected and traced by security services. Recruitment must be smart and successful in terms of obtaining the best possible recruits. Successful recruitment represents a unique entry into the organisation, which is also important for selected individuals’ future contribution.

One might think that individual terrorist and extremist organisations would take different approaches to recruitment. While this may be so in individual cases, when looking at the theme more broadly it emerges that recruitment is a flexible multi-tool process able to be smartly adapted to the circumstances, needs and character of targeted individuals. Based on the two above investigated cases, we may confirm the hypothesis that al-Qaeda and ISIS have flexibly used different models and approaches to the recruitment of new members. Our assessment of the general recruitment process and particular recruitment activities in the case of the two terrorist cells considered confirms that the same recruiters interchangeably use different recruitment models (the Net, the Funnel, the Infection, Seed Crystal) and recruitment approaches (public and proximate, public and mediated, private and proximate, private and mediated) to a surprising level. Such flexibility was detected not only over a longer time period, but also in the case of recruiting members for specific terrorist cells and even the recruitment of individual persons by al-Qaeda and ISIS. Prior to 9/11, al-Qaeda had mainly relied on models (Net and Funnel) based on the proximate approaches. However, both terrorist organisations have also successfully adjusted their recruitment activities in the post-9/11 security environments of Europe and the USA. The two terrorist organisations are increasingly relying on public-mediated and private-mediated approaches by using the Internet as a tool to recruit new members, either through online forums, password-protected websites, or social media (Seed Crystal and Funnel Models). One should also not ignore the recruitment activities based on the private-proximate and public-proximate approaches. Namely, radical mosques and prisons in Europe have been the most common places for both terrorist organisations to recruit some of their members (Net and Infection Models) ever since 9/11 (see Cuthbertson, 2004, p. 15; Bloom, 2017 −615; pp. 612; Mosques in Switzerland’, 2019; Ristic, 2016, p. 4; Reynolds, 2016, p. 41).

The flexible use of recruitment models and approaches is also evident in the recruitment of individual members of the Hamburg and Brussels terrorist cells. Members of the former were recruited according to the three models and in a combination of the three approaches. Extremist online and offline propaganda that spread across the Internet and through other media served as a tool for priming the four individuals for the recruitment process (Seed Crystal Model and public-mediate approach). The most prominent recruitment place was the Al-Quds Mosque in Hamburg where all four core members of the cell were contacted by Mohammed Haydar Zammar (the Net Model and public-proximate approach), while the four members’ private apartment provided safety and privacy for further radicalisation and recruitment (the Net Model and private-proximate approach). While the Hamburg cell was formed prior to 9/11 when the security environments of Europe and the USA still allowed recruitment, the case of the Brussels cell clearly shows adaptation to the new security measures. Namely, the recruitment process of the three studied members of the Brussels cell reveals a shift towards those models and approaches that offer greater anonymity (the Seed Crystal Model and public-mediated approach) and privacy (the Funnel and Infection Models combined with private-proximate, public-proximate and private-mediate approaches), leaving out the Net Model, which requires the recruiter’s public exposure to wider groups. The recruitment was evidently based on individualised approaches enabling trusted relationships to form. This was achieved in the physical environment, either in a prison, via a one-to-one approach on the streets, or through an already established friendship, but also in cyberspace by way of encrypted messaging applications.

Our study also shows that on a general level the recruitment models and approaches have over time increasingly moved to cyberspace. Cyberspace gives additional possibilities and width for recruiters. Cyber recruitment does not require the direct physical participation of recruiters and is hence a more secretive and less risky activity. This trend has been correlated to the growing possibility of lone actors to self-radicalise over the Internet and become isolated terrorists. On the other hand, the analysis of recruitment for the two terrorist cells shows that online platforms played only a limited role in the recruitment of their members. Even in recent cases, more important factors were physical locations and contexts. While contemporary literature on terrorist recruitment mainly focuses on the role of new communication technologies in this process (e.g., Tonnessen, 2017; Weimann, 2016; West, 2016), our study shows that some terrorist attacks in the USA and Europe with the most drastic consequences were carried out by terrorist cells whose recruitment was strongly based on physical approaches (a mosque, an apartment, city streets, a prison and in the context of a friendship).

We found Gerwehr and Daly’s research model useful while studying al-Qaeda’s and ISIS’ contemporary recruitment practices on a general organisational level. However, we noticed that the more recruitment processes are moving online towards self-radicalisation, self-recruitment and utilising encrypted messaging applications, the more difficult it is to accurately identify how an individual was recruited for the terrorist organisation. While it is possible to link this process to private and public mediated approaches, it is more difficult to determine exactly within which model’s framework the recruitment took place.

A comparison of recruitment models and approaches raises the question of which model and approach is more relevant. One cannot say which is more important on the conceptual level because they are all simply different ways of achieving the same goal. To make comparisons of the different approaches’ relative importance in practice, we would need exact figures of how many members were recruited by a given technique by entire organizations. Data of this nature unfortunately do not exist. Nevertheless, we can attribute ISIS’s considerable success with attracting a large number of members from Western countries mostly to the Seed Crystal recruitment model (public and mediated approach). In contrast, al-Qaeda primarily adopted the Net model, characterized by the public and proximate approach, to recruit its Western members. However, closer examination of the ways members of the Hamburg and Brussels cells were recruited reveals stronger reliance on models based on the private and proximate approach (the Infection and Funnel models). An interesting comparative finding is that all members of al-Qaeda’s Hamburg cell were initially recruited through the Seed Crystal model, whereas we observed this only with respect to one member of the Brussels cell of ISIS.

Science could be advanced in several ways, such as by developing a new model and testing it on new data, developing a new model and testing it on old (previously tested) data, applying an old/existing model and testing it on new data etc. This paper brings the following novelties to the current recruitment academic debate by: (1) supplementing or upgrading a known research model; and (2) testing the supplemented model on new data regarding ISIS and its Brussels cell as well as on the upgraded quality of data on al-Qaeda due to the longer time span considered. We applied a refined research model to an old case (al-Qaeda) in a period following publication of the original model and also to a newer case (ISIS). The paper further contributes to the wider debate on terrorist radicalisation and recruitment by bringing a more holistic approach to analysing the recruitment process, including both online and offline settings, as well as comparing the recruitment processes of the two most dangerous terrorist organisations. We also recommend improving Gerwehr and Daly’s research model by including findings on the role of social media and encrypted messaging applications in terrorist recruitment, as well as applying the model to other terrorist organisations such as Boko Haram, Jemaah Islamiyah or Hezbollah. Exploring the diversity and similarity across the radicalization milieus should be the next step.

Some readers might ask why is it necessary to distinguish between the models and approaches if multiple ones are used and they all overlap somewhat. Our answer stems from the basic methodological understanding of the development of social science. According to Ragin (1994, pp. 31–47), the main goal of social research is to identify order in complexity. Social research has several other major goals, including identifying general patterns and relationships, testing and refining theories, exploring diversity, advancing new theories, making predictions etc. In their model, Gerwehr and Daly tried to identify general typical patterns in recruitment by classifying various recruitment models and approaches. In the methodological words of Strauss and Corbin (1998, p. 103, 105), they engaged in classifying “to group similar events, happenings, and objects under a common heading or classification”. This implied some sort of abstracting where the goal was “to see new possibilities in phenomena and classify them in ways that others might not thought of before (or if considered previously, were not systematically developed in terms of their properties and dimensions)”. If Gerwehr and Daly are correct, this implies that recruiters may be expected to use one or several models or approaches. It takes time and effort to build a tailored model and approach in specific contexts in practice. Our hypothesis formed part of the next step of testing and refining theories. It was created as part of using grounded theory (bottom-up from data to assumptions and theories). Our initial look at the data reflected the considerable mix of models and approaches and some interchangeable use of them. Previous sources have not mentioned this specific aspect. This allows us to say that our hypothesis and conclusions add new knowledge with regard to the great and unexpectedly large capacity of recruiters to flexibly and interchangeably use various models and approaches, including when recruiting members for the same cells and not only over a longer period of time. To the best of our knowledge, this finding has not been stipulated or confirmed by other researchers. Although one might claim that this could have been assumed and is not new, it is now proven based on concrete cases.

The question arises of how the knowledge on recruitment thus acquired affects counter-terrorism and related counter-recruitment activities. We believe that knowledge concerning recruitment models and approaches should be used in detection and prevention activities in counter-radicalisation and counter-terrorism. Specifically, security and intelligence services should screen all new and alternative social media platforms given that ever more users are migrating to them, while their content remains less regulated. They should also seek cooperation on security matters with start-up tech companies, developing encrypted messaging applications and keep an eye on the emerging technologies that facilitate social interactions, like the metaverse. Such new virtual reality platforms could be used by extremists to directly interact with other users through their avatars. At the same time, physical locations like mosques and prisons remain potential recruitment grounds for terrorists and should accordingly not be neglected by security and intelligence services.

In the concluding discussion, we can also look at this paper and related findings from a broader perspective of Critical Terrorism Studies and the Neo-Orientalist debate. The entire theme of recruitment is actually caught up in the West—Muslim constructivist narratives and struggles. Accordingly, a Neo-Orientalist imaginary or representation of Arabs and Muslims has been rhetorically and politically constructed by the anthropocentric West and some Arab political leaders, in which Muslims are portrayed as “new barbarians” or as an ontological threat to liberal, democratic, and secular Westphalian society. This threat construction has led to increasing Islamophobia, fear and hatred of anything involving Muslims and the need to intervene and transform the lawless and terror-prone Middle East into a lawful new Middle East. Important implications of this trend were also evident in Western societies, where Muslims felt increasingly stigmatized and trapped in a deep cultural dualism between Islam and the West (Al-Kassimi, 2021b), contributing to the motivations of many potential foreign fighters in Syria and elsewhere. Their recruitment process was likely facilitated and accelerated by the guaranteed presence of several motivating factors identified by Precht (2007) in his comprehensive study of homegrown radicalization, such as the Muslim identity crisis, the experience of discrimination, segregation, and the creation of parallel societies, the relative absence of public debate about Islamist terrorism, the myth of jihad and the desire for activism. Moreover, the Orthodox Terrorism Studies typically ignored the importance and consequences of states’ activities as agents of terrorism (see Al-Kassimi & Simons, 2019). State agents can engage in the same strategies as non-state terrorists, such as blowing up civilian aircrafts (e.g. the Lockerbie attack by the Libyans), the Rainbow Warrior ship by the French (see Al-Kassimi & Simons, 2019, p. 12), and operation Timber Sycamore. The latter was activated in 2012 by the United States, the United Kingdom, Israel, Saudi Arabia and others to provide weapons and train “death squads” to create disorder in the Middle East, increasing the recruitment locally and globally. This operation further contributed to the existing narrative about the Muslim threat and the need for authorities to launch a responsive operation (see Al-Kassimi, 2021a). All of this means that the topic of recruitment has always been a dependent part of a much larger constructivist processes between non-state and state actors.

Final statement

This paper was not submitted to any other journal.

Disclosure statement

The authors declare that they have no relevant or material financial interests that relate to the research described in this paper.

Additional information

Funding

This research was partially supported by the Slovenian national research association (ARRS, grants P5-0206, MR 54749).

Notes on contributors

Iztok Prezelj

Iztok Prezelj is a Professor and Dean at the Faculty of Social Sciences, University of Ljubljana, Slovenia. As a Vice-Dean for Scientific Research in the period 2017-2021, he was directing research process at the Institute of Social Sciences with 20 research centers. He was also a Head of Defence Studies in the period from 2015-2017. Iztok Prezelj published widely in the fields of national & international security, terrorism & counter-terrorism, intelligence, crisis management, threat & risk assessment and critical infrastructure. He was a guest researcher or lecturer at the Princeton University, Leiden University, University of Sarajevo, University of Vienna, WEU Institute for Security Studies, etc. At the George C. Marshall Center - European Center for Security Studies, he was an Adjunct Professor in the Programme on terrorism and counter-terrorism (PTSS) in 2014. He is also a president of the Euro-Atlantic Council of Slovenia. Dr. Prezelj comments regularly on security issues for the national and foreign media. He obtained his Ph.D. in 2004 at the University of Ljubljana on the topic of crisis management. Since 2014, he is also a guest professor at the Faculty of criminal justice and security, University of Maribor.

Luka Zalokar

Luka Zalokar is a researcher at the Defense Studies Department, Faculty of Social Sciences at the University of Ljubljana. He holds M.A. in Defense studies, his research activities involve communication in crisis management, terrorist recruitment and military technology. He also teaches the course on defense and military technology.

Notes

1. Ranstorp (2010) argues the following factors make Muslims receptive and vulnerable to recruitment: lack of debate about justifications of violence, stigmatising, polarising public debate, identity crisis, social alienation, presence of radical imams, glorification of jihad and martyrs, a spiral of discrimination, criminalisation etc.

2. According to Neumann and Rogers (2007), radical imams play an important role in the recruitment process. The authors stress their four main roles: (1) they distribute propaganda messages; (2) they are seen as a religious authority; (3) they attract individuals eager to join Islamist terrorist organisations and integrate them into an existing terrorist network; and (4) they strengthen militant jihadist movements by connecting different terrorist networks between each other and thereby help with the creation of a network of networks.

3. At this point, the phenomenon of individual jihad should also be mentioned. A successful radicalisation and recruitment process does not always end in a trip to training camps or even membership of a particular terrorist cell. In July 2011, al-Qaeda began to propagate individual jihad, i.e., the execution of a terrorist attack by an individual using their own means and without any ties to a terrorist group (Europol, 2014).

4. For a detailed description of ISIS’ online recruitment process, see (Reynolds, 2016), pp. 40–44.