Radicalization of Islamist Terrorists in the Western World

By Ryan Hunter, M.A., and Daniel Heinke
Radical Islamist terrorists before a sunset. ©

Modern Islamist extremism emerged in the middle of the last century, but, in its beginnings, was limited to the Middle East. That dramatically changed in the aftermath of the assault on 9/11 when the threat Islamist terrorism posed to countries in the Western world became apparent. While it was not the first time Islamist militants targeted a Western country, the scale of the attack—killing almost 3,000 people and destroying the iconic Twin Towers—demonstrated that the threat from such organizations and individuals had shifted. Since 9/11, that menace continues to transform, and Western societies increasingly must deal with a rise in so-called homegrown Islamist terrorism.

In itself, homegrown terrorism is not a new phenomenon as nationals of the respective country conduct the vast majority of typical nationalistic or politically motivated terrorist activity. However, violent Islamist ideology inspiring homegrown terrorism in the West represents a new aspect.

The terms homegrown terrorism and homegrown violent extremism typically describe radicalized Western citizens or local residents. They adopt an extremist religious or political ideology hostile to Western societies and values and turn to terrorism. The word radicalization has many definitions in intelligence and law enforcement communities. The FBI defines it as “the process by which individuals come to believe their engagement in or facilitation of nonstate violence to achieve social and political change is necessary and justified.” German law enforcement and intelligence agencies describe it as the “turning of individuals or groups to an extremist mind-set and course of action and the growing readiness to facilitate or engage in nondemocratic methods up to the execution of violence to achieve their goals.”

Radicalization: Who and How

Counterterrorism is more art than science. Radicalization, especially of Islamist extremists, only recently has become a serious research topic of law enforcement organizations, intelligence agencies, and academia. Yet, data still are not extensive and have resulted mainly from shared analysis of executed or prevented terrorist attacks. Baseline data for comparison have proven difficult to collect because of legal restrictions and other issues. Collection also presents challenges because, generally, Islamist terrorism is not static, but highly flexible, including its recent manifestation into homegrown terrorism. This new manifestation does not replace known variations of Islamist terrorism, but represents additional threats possibly encountered independently or in combination with foreign-based efforts. To counter this threat, various government studies from western European countries and comparable research in the United States have considered two key points of homegrown violent extremism: who becomes radicalized and how the radicalization process works.

Who: Common Denominators

Analysis in both Europe and the United States showed that violent Islamist extremists represent a broad range of the population. In Western countries, most of these individuals have been nationals or have had legal status in the country. They are ethnically diverse, although in some European countries, the majority of identified Islamist terrorists comprised part of the largest immigrant Muslim community (e.g., France: Algerian; Great Britain: South Asian; Spain: Moroccan). However, this does not hold true for other large countries, such as Germany, Italy, and the United States.

A car engulfed in flames. ©

Additional stereotypes do not prove valid either. Most terrorists are male, but women also play an important role. The majority of extremists are between 20 and 30 years old, but a number of older men—sometimes women—require consideration too. While numerous individuals are single, many also have steady relationships and children. Their educational backgrounds span the entire spectrum, from no formal qualifications to postgraduate degrees (although the majority worked in relatively low-grade jobs). Some analysis indicated that many radicalized Islamists in western Europe tend to seek a group-oriented life, and group dynamics also have proven a common factor in promoting terrorist activities in the United States. A disproportionately high number of Islamist extremists in the West converted to Islam, but this neither insinuates a general tendency toward radicalization among converts nor does it deny the fact that the majority of Islamist extremists were born into the Muslim faith. Most of these terrorists’ prior criminal involvement was minor or nonexistent. Homegrown Islamist extremists are so socially and demographically diverse that no universally accepted profile can be compiled using sociodemographic characteristics.

How: The Radicalization Process

On the surface, the pathways to terrorism seem as varied as the actors themselves. Extremists have many diverse starting points and follow many different paths that lead to ultimate involvement in terrorist activities. The existence of a common end point has led many individuals and organizations with an interest in radicalization to characterize these pathways as variations of the radicalization process, and much effort has focused on identifying common aspects to understand and—in the end—counter this progression. In the course of this research, several analyses of the radicalization of identified Islamist terrorists have been conducted, mainly based on data from law enforcement agencies and intelligence services, such as the FBI, New York City Police Department, German Federal Criminal Police Office, Dutch General Intelligence and Security Service, Swedish Security Service, Danish Security and Intelligence Service, and the British government.

While these agencies’ models and explanations are not entirely congruent, they suggest a prevailing radicalization model composed of three main components: grievance, ideology/narrative, and mobilization.1 The breakdown of these distinct components may be useful for law enforcement and intelligence agencies, as well as other government or nongovernment partner institutions, to assess the circumstances and potential radicalization of certain individuals or groups. 

However, these components do not reflect an automatism and do not follow a fixed timeline of radicalization. Obviously, not all individuals who begin this process complete it. Many stop or even abandon this development at various points and for different reasons; some reenter later and begin again. Others do not follow the implied sequential development, but move from one radicalization stage to the next. Yet other individuals do not seem to make well-considered decisions within this process, but follow it like a slippery slope. The radicalization process can take several years for some persons, but develop very quickly for others.


Discontent seems to serve as the prerequisite of the radicalization process. Issues driving this attitude toward individuals in the West may include perceived persecution of Muslims throughout the world; a sense of uprootedness, alienation, or lack of acceptance; feelings of discrimination, especially among second- or third-generation immigrants; or a general search for identity.

This discontent may be based on individuals’ actual experiences or those of other people within their community, or it may result from the normal process of identity formation among young people. These latter feelings of uncertainty of oneself during adolescence and early adulthood are common and well-known in developmental psychology, but after an individual feels rejected by society, these emotions can lead to a deep identity crisis and cause one to search for a new purpose of life. Some Muslim-born individuals may link experiences of disadvantage or nonbelonging to their faith and judge them to be an expression of cultural and religious discrimination.


Ideological framing adopts this diffuse feeling of discontent and leads it in a defined direction. The idea of “us”—the ummah (community) or ummat al-mu’minin (the community of the believers)—defending against “them”—the nonbelievers conducting an alleged war against Islam—secures a strong bond among the followers while alienating them from Western citizens.

“Radicalization, especially of Islamist extremists, only recently has become a serious research topic of law enforcement organizations, intelligence agencies, and academia.”

This narrative typically finds its ideological footing in a form of Salafism, adherence to which is viewed as the ultimate distinguishing feature between right and wrong. Interpretations of Salafism range from a purely personal religious conviction with an emphasis on purifying the believer’s way of life to a jihadi orientation that demands its followers to take on the fight against Western governments and “apostate” Muslim (especially Middle Eastern) regimes held responsible for the suffering of all Muslims. This jihadi Salafism emphasizes God’s undisputed and sole sovereignty (hakimiyyat Allah) and views the Qur’an and the Sunnah of Muhammad as the only acceptable sources to define right and wrong. In consequence, this ideology bans the idea of democracy and man-made law in general as un-Islamic; Western societies are considered sinful and a danger to the right order of mankind.

Some well-read scholars justify these claims with in-depth theological arguments in favor of violent jihad,“the use of violence against persons and governments deemed to be enemies of fundamentalist Islam, especially the West .”2 However, Islamism and Salafism, when presented as an ideology or narrative to promote radicalization rather than as a religion, tend to be kept simple and without theological depth.

The core significance of this ideological framing component should not be sought on the basis of its content, but because it provides followers (true believers) with an idea of their “true purpose” and sense of belonging to a transnational community. By accepting this highly polarized worldview and its narrow set of rules, the uncertain individual searching for meaning receives simple answers, as well as a comprehensive framework of social and moral norms and values. Terrorist movements or ideologues then can build on this ideology by strengthening the perception of global Muslim suppression; the picture of Islam under threat, triggering the belief that the Muslim community and the radicalized individual exist in a state of permanent self-defense; and the view of violence as a legitimate response.

A man with a rifle looks out upon his surroundings during sunset. ©


In the majority of cases, extremists become radicalized in large part through intensifying social interaction with other people with shared beliefs. Such a relationship then results in a mutual push toward violence. Sometimes, a spiritual leader will goad individuals to take such actions. The “lone wolf/lone offender” has served as the rare exception. However, in recent years, prominent attacks in the United States and Europe were carried out successfully by individuals with few ties to other extremists, highlighting the threat posed by radicalized persons who are relatively alone.

The sense of identity and belonging that likely accompany group interaction may provide a psychological and emotional reward that exceeds the original ideological motivation. Often, this group experience is fueled intentionally by isolating to a certain degree potential or new members, using means, such as overseas travel and training camps (especially in Europe). Through ongoing mutual assertion of the righteousness of shared beliefs, new moral norms and standards replace existing ones. Group members increasingly see violence as an acceptable and legitimate, even desirable, way to achieve the common goals of the group. Visual propaganda is intensified, including hate videos with high emotional impact. Contrasting images of perceived or factual atrocities against Muslims with “glorious” attacks by jihadis and the celebrated killing of Westerners (the beheading of a U.S. soldier serves as one heinous example) are featured, and all Islamist terrorist attacks against infidels, non-Muslims, and “apostate” Muslims are endorsed. As extremists see it, jihad is increasingly supported. This ultimately may lead to an ideologue that calls for the direct participation in jihad or self-persuasion to join the violent fight against the perceived enemies of Islam.

Typically, mobilization is the only radicalization component involving specific actions possibly subject to criminal prosecution. Potential operatives are recruited by an extremist group or individual, small groups are prompted to form a terrorist cell of their own, and extremists begin preparing direct attacks or supporting others planning to attack. In the United States, mobilization also is the transition phase from ideology—protected under the First Amendment—to action, which becomes criminal activity. Logically, law enforcement and intelligence resources will focus on mobilization because activities conducted in this latter stage of radicalization present the opportunity to make arrests. Further, the majority of those harboring grievances and adopting the ideology do not progress to violence. However, this final phase can be short-lived, enforcing the need for intelligence agencies to fully understand and become aware of the earlier components.

Beyond these three components, the additional element of a specific traumatic experience (a personal or political “tipping point”) may trigger involvement in terrorist activities.3 Based on available data, such tipping points are not reliably verifiable yet, and such experiences likely will be so varied and personal that trying to identify them may add little value to the day-to-day work of law enforcement and intelligence agencies. Nevertheless, their identification could serve as a worthwhile approach for further research.

Role of the Internet

Online radicalization presents a primary concern. Extremists use a variety of tools that range from dedicated password-protected jihadist Web sites, forums, blogs, social networking resources, and video-hosting services to professionally produced online English-language propaganda magazines, such as Inspire magazine, established by al Qaeda in the Arabian Peninsula (AQAP). These online assets, serving as a sort of “virtual jihad university,” can play a role in all three radicalization components.

  • Grievance: The Internet allows rapid and widespread dissemination of information about events that may fuel grievances. Often, such propaganda is intensified by highly emotional images combined with an amplifying comment or soundtrack. Because anyone can post content online, individuals have a forum to present the material in a way that supports their point of view no matter how extreme.
  • Ideology/Narrative: Similarly, the Internet allows the extremist narrative to spread globally. Anwar al-Aulaqi, a Yemen-based American citizen and member of AQAP, is perhaps the best example for English-speaking audiences. His lectures and contributions to Inspire magazine are widely available online. It no longer is necessary to have an ideologue at a local mosque or gathering place to inspire future extremists.
  • Mobilization: How online interaction impacts mobilization poses pressing questions inside the United States and Europe. Because extremists interact online with other like-minded individuals despite geographical differences, can they develop the group dynamics that lead to violence? How effective are social networking sites as a venue for terrorists to spot and assess would-be extremists? In a recent case in Germany, a 21-year-old extremist accused of fatally shooting two U.S. soldiers and wounding two others at Frankfurt airport on March 2, 2011, claimed to be radicalized through the Internet and motivated to take action after seeing propaganda videos.

Approaches for Counterradicalization

Law enforcement activities directed solely against an individual’s illegal activity after radicalization likely start too late and do not provide a sufficient answer to the complex phenomenon of homegrown Islamist terrorism. An effective counterradicalization program has to confront one, preferably all, of the components of the radicalization process and involve a variety of participants beyond the law enforcement and intelligence communities.

“Analysis in both Europe and the United States showed that violent Islamist extremists represent a broad range of the population.”

It seems that in each component, efforts of government and nongovernment actors can address issues at the level of the individual or the external environment. While potential counterradicalization activities and actors are wide and varied, a few highlights stand out.

  • Prevent or Properly Handle Grievances: On an individual level, efforts should focus on improving young Muslim immigrants’ participation in society regarding their social, educational, and economic situation. Externally addressing discrimination and other issues that give rise to grievances also must be taken seriously.
  • Counterideology: Individually, potential young extremists should be provided clear, descriptive, and unbiased information. Misleading or agitating propaganda should be countered aggressively. At the external level, to educate Muslims and address possible misunderstandings, authorities should provide open information on extremist Islamist trends and government programs to these communities, preferably in concert with respected Muslim citizen representatives. Proposed steps to prevent the spread of violent ideologies, such as Web site disruptions, also have to be evaluated while addressing questions of free speech and effectiveness.
  • Countermobilization: Efforts include the classic antiterrorism approach of intelligence and law enforcement agencies collecting and analyzing information on extremist persons or groups, enacting early detection programs, identifying potential threats, and disrupting plots and other extremist activities. At one level, these activities may target individual would-be operatives or recruiters and known communication or facilitation nodes.


Homegrown individuals engaging in Islamist extremism are both demographically and socioeconomically diverse, preventing the development of a reliable profile. Yet, all these persons develop a new mind-set as they undergo radicalization. While no typical pathway exists for this radicalization process, three main components include deeply ingrained grievances as the basis for an identity crisis, an elementary Islamist/Salafist ideology providing a sense for one’s existence and sense of belonging to a chosen community, and the individual’s mobilization to join the terrorist movement. The understanding of these distinct components of the radicalization process may help law enforcement and intelligence agencies assess potential cases of radicalization and lay the groundwork for other government or nongovernment institutions to develop defined counterradicalization efforts.

Mr. Hunter is an intelligence analyst in the FBI’s Counterterrorism Analysis Section.

Dr. Heinke is the counterterrorism coordinator for the State Ministry of the Interior in Bremen, Germany.


1 Peter Neumann, “What Motives and Circumstances Lie Behind Persons Affiliating with Violent, Radical-Islamist Groups and Committing Acts of Violence Themselves?” (lecture at the autumn conference of the German Bundeskriminalamt, or Federal Criminal Police Office, Wiesbaden, Germany, Oct 19, 2010).

2 For example, Jordan-based Abu Muhammad al-Maqdisi.

3 Peter Neumann.

“An effective counterradicalization program has to confront one, preferably all, of the components of the radicalization process and involve a variety of participants....”