Islamic violent radicalization and terrorism has been a global issue for the past three decades, and its manifestations in the Western world (including Europe, the United States, and Canada) have led to extensive and distorted media coverage (Nesser, 2015). Although the number of victims in Western countries is very low compared to the rest of the world (Global Terrorism Index, 2015), terrorist attacks in the Western world seem to have the largest impact on the pursuit of counterterrorism efforts by Western policymakers. The growing number of fatalities and frequency of these Islamist terrorist attacks in the past few years have led to an increased sense of urgency among the general population as well as Western authorities. The recent tragedies that took place in France, Belgium, and Germany are grim reminders of the pressing security concern and the need for extensive research on the topic of home-grown terrorism in order to prevent further loss of innocent civilian lives.

Aside from radicalized Western Islamists who are first-time militants and engage in domestic terrorism, there is another threat: foreign fighters. Loosely defined, foreign fighters are ‘non-citizens of a state experiencing civil conflict who arrive from an external state to join an insurgency’ (Malet, 2015, p. 459). The number of Western residents leaving to join the fight in Syria, or to train and come back for domestic operations, has risen ever since the civil war broke out in 2011 (The Soufan Group, 2015). This has led Western policymakers to debate the treatment of these foreign fighters upon return to their home countries. With the Serious Crime Act 2015, passed in March 2015 in the UK, the Criminal Justice (Terrorist Offences) Amendment Act 2015, passed in Ireland, and a new law in 2014 under France’s Criminal Code, making it illegal to incite and publicly justify terrorism, multiple Western countries have introduced measures to counter the flow of foreign fighters (Wheelans, 2016). Although only a minority of foreign fighters tend to return, these numbers have increased significantly especially in the year of 2015 (The Soufan Group, 2015), although concrete statistics are not available at the current time of writing. The reason why returnees may be seen as possible threats to Western society, is the experience they may have obtained in militant fighting during their time abroad. If foreign fighters return with the intention to carry on their violent Jihad (holy war; see also Silke, 2008; Nesser, 2004) in the Western world, their experience can lead to more lethal domestic attacks than those of first-time militants engaging in domestic terrorism (e.g., Sageman, 2010; Cruickshank, 2010; Clarke & Soria, 2010). For instance, when Hegghammer (2013) built a data set of Islamist attack plots in Western countries between 1990 and 2010, he found evidence for a ‘veteran effect’; the data set showed that the presence of a veteran (a domestic fighter with prior foreign fighting experience) increased the probability that an attack was executed by a factor of about 1.5. With a total of 106 plots of which 24 were executed, 14 were in the presence of a veteran. Hegghammer’s data set also showed that the presence of a veteran doubled the chance that an attack would kill: 8 out of 12 lethal attacks were in the presence of a veteran.

The rising number of Western-born and/or -raised individuals attracted to militant Islamism calls for further research in the field. Undeniably, the destruction of Muslim-majority countries, in part due to Western foreign policies, lies at the root of modern day Islamist terrorism. However, this does not explain why only a minority of the worldwide Muslim population turns to militant Islamism. The question, thus, still remains: Why do some individuals become radicalized and engage in violent behaviours in the name of Islam, justifying the killings of innocent civilians? In order to answer this question, the factors contributing to the change in mindset of radicalized individuals and the resulting violent behaviours need to be elucidated. Investigation of terrorist behaviour and its causes will be a step towards finding solutions and possible preventative measures for this worldwide phenomenon. The present paper focuses on cases of Western Islamists who have engaged in domestic terrorism. Based on existing literature, this work attempts to determine whether we can identify factors that contribute to Western Muslims joining Islamic extremist organizations and engaging in terrorist violence in the West (including Europe, the United States, and Canada). Four factors are discussed, namely identity crisis, relative deprivation, personal characteristics, and empathy (for a summary, see figure 1).

Identity Crisis

Identity is a dynamic and constantly changing phenomenon that can be derived from multiple aspects of one’s existence (Sen, 2008): religion, gender, marital status, economic status, occupation, race, political beliefs, et cetera. It is possible for an individual to simultaneously be a Muslim, a European citizen, a believer in democracy, and someone who respects cultural differences and human rights (Murshed, 2011), thus to incorporate different beliefs and convictions into one’s identity. However, Maalouf (2011) suggests that in times of stress or uncertainty, individuals have a tendency to primarily identify with the aspect of their existence that is under the fiercest threat or attack. Identity issues are prominent within the Western Muslim community. Second and third generation Muslim immigrants have to manage a Western identity, while simultaneously inheriting an ethnic identity from their family. The effort of finding a balance in between two completely different cultures and belief systems is continuously challenged by social as well as political factors. Within this group, adolescents with a lack of self-certainty are highly prevalent (Meeus, 2015).

Maalouf’s theory implies that among other things, the ongoing culture of Islamophobia and anti-immigrant sentiment that is growing in Western society (Murshed & Pavan, 2011) as well as the foreign policies of Western countries are leading uncertain Muslim adolescents to attach more salience to the Islamic part of their existence, thus making ‘Muslim’ their primary identity (Abbas & Siddique, 2012). This is in accordance with an empirical study conducted by McGregor and colleagues (2001), showing that individuals react to uncertainty by hardening their attitudes and increasing their convictions. As beliefs are strengthened (which in itself is not necessarily negative; Tausch, Spears, & Christ, 2010), and the individual immerses in religious exploration, he or she will inevitably be exposed to violent and radical interpretations of Islam through the Internet, sometimes their social environment, and through media reports (King & Taylor, 2011). When an individual is in an uncertain period in their life, he or she will be susceptible to extreme ideas and groups (Hogg, Sherman, Dierselhuis, Maitner, & Moffitt, 2007; Hogg, Meehan, & Farquharson, 2010). The reason for this being the allure of clarity within these extreme ideas, due to a complete lack of ambiguity. The rigidly defined, simplistic rules associated with extremism provide a promise of certainty for the uncertain individual. Since violent interpretations of Islam provide well-defined and clearly prescriptive rules with a black-and-white worldview, joining violent radical groups is an easy means of reducing uncertainty in Western Muslims battling with an identity crisis (Hogg, 2000).

Perceiving Islam as being under attack contributes to not only an enhanced salience of the religion itself, but also to development of resentment towards mainstream society in a number of Western Muslims (Murshed & Pavan, 2011; Abbas & Siddique, 2012; McCauley, Leuprecht, Hataley, Winn, & Biswas, 2011). The latter seems to be one of the crucial ‘ingredients’ of violent radicalization, and an ‘us versus them’ mentality. The term ‘violent radicalization’ is used, since ‘to radicalize’ means to reject the status quo, but not necessarily in a violent or problematic manner (Bartlett, Birdwell, & King, 2010). What differentiates violent radicals from non-violent radicals, is that the latter are able to balance their negative views (on foreign policy, the media, and security related measures) with a genuine appreciation of Western society and its values, whereas violent radicals show a hatred for Western society and culture in general (Bartlett, Birdwell, & King, 2010), with foreign policies and Western power building in Muslim-majority countries at the root of this hatred. Although personal experiences can lead to this shift in self-identity, wrongdoings towards other Muslims can have an equally strong or even stronger influence. Namely, different experiences of Islam being under attack generally tend to be interpreted within the context of the collective Muslim identity (Mythen, Walklate, & Khan, 2009). For instance, in one study, a poll of 430 Ottawa Muslims showed that political grievances (disapproval of Canadian foreign policy) are better predictors of attitude toward Western powers than personal experiences of discrimination (McCauley et al., 2011).

Identity crises are common amongst second generation Muslims in the West, because they have to simultaneously manage different cultural aspects of their lives. When the religion of Islam is perceived as being under attack, the uncertainty of identity leads second generation Muslims to be more susceptible to strengthening the Islamic part of their identity. The current growing culture of Islamophobia and anti-immigrant sentiment in the West not only leads to the strengthening of Islamic identity, but also to the development of resentment towards mainstream Western society. Wrongdoings towards Muslims are interpreted within the context of the collective Muslim identity, contributing to the engagement in Islamist terrorist behaviours.

Relative Deprivation

Another aspect which contributes to Western Muslims perceiving their religion as being under attack, besides social stigma, is economic deprivation; numerous studies have reported that Western Muslims have lower labour force participation, employment, and occupational attainment (Cheung, 2014; Bisin, Patacchini, Verdier, & Zenou, 2011; Connor & Koenig, 2013; Luthra, 2013; Heath & Martin, 2013). Economic deprivation is a component of Ted Gurr’s relative deprivation theory (Gurr, 1968; Gurr, 1970). Gurr defines relative deprivation as a person’s belief to receive less than deserved, and the term furthermore entails the perception that one’s group is being treated less well than other groups (Feddes, Mann, & Doosje, 2015). He theorizes that this collective discrepancy creates frustration and, in turn, contributes to the use of violence. Freytag and colleagues (2011) tested the hypothesis that poor socio-economic development is conducive to terrorism, by running a series of regression analyses for 110 countries between 1971 and 2007. Their findings imply that socio-economic factors indeed play a role in terrorism. Considering the levels of disadvantage many Western Muslims experience, it is not surprising that many Muslim communities find themselves treated unfairly (Silke, 2008). These feelings of marginalization also contribute to the ‘us versus them’ mentality and may reinforce distancing of oneself from society and becoming attracted to violent radicalization (Feddes et al., 2015). When individuals feel triggered by the existing social order that they perceive as ‘unfair’, it is easier for terrorist organizations to recruit these individuals by building on related grievances, whether these grievances are national or global (Krieger & Meierrieks, 2011).

An exploratory study, examining individuals and networks involved in terrorist activity in Europe in the period of September 2001 to September 2006, showed that very few jihadi terrorists were of higher socioeconomic class; many of the first, second, or third generation immigrants had in common that they came from the lower strata of society (Bakker, 2006). Although at first glance this seems to strengthen the typical image of the Islamist terrorist being from a ‘poor’ background, these findings as well as the unemployment rate in the sample were no different from general European averages within immigrant Muslim communities. This implies that those who are unemployed are not necessarily more likely to engage in terrorist activity than those who are not. As mentioned before, an experience can be interpreted within the context of the wider Muslim community, whether or not it is a personal first-hand experience (Silke, 2008). Thus, it is proposed that, among other forms of relative deprivation, the higher unemployment rate among Western Muslims as opposed to the mainstream population contributes to feelings of injustice in both the employed and the unemployed, and can therefore contribute to engagement in violent behaviour. It is the collective relative deprivation, rather than the personal relative deprivation that will motivate a person to act (King & Taylor, 2011). Again, the sense of a collective identity seems to be the driving force behind feelings of injustice (e.g., Awan, 2008). Besides relative deprivation in terms of employment and lower income, the Western Muslim community is under-represented in public life (Murshed & Pavan, 2011), has a disproportionately high prison population (Awan, 2008), and poor housing facilities (Awan, 2008).

Apart from the disadvantages experienced by Muslims in the Western world, the injustice experienced by Muslims in the rest of the world is another (most likely more crucial) contributing factor to the resentment of Western society and the resort to violence among Western Muslims. Not only is this deprivation much more severe than that experienced by Muslims living in the West, but the use of it in terrorist propaganda makes it an extremely potent inciting factor (Silke, 2008). Through use of death-related imagery, potential recruits are exposed to the idea of Western destruction in ‘Islamic lands’ (e.g., Carey, 2012; The Bureau of Investigative Journalism; Devereaux, 2015; Afghan Paper, 2013; Afghan Paper, 2014), increasing identification with the Islamic community and support for the use of terrorist violence (Farwell, 2010; Finsnes, 2010). Findings from a study conducted by Pyszczynski and colleagues (2006) provide evidence for this ‘mortality salience’ effect; when reminded of death, both Iranian and American participants are more likely to show support for extreme violent solutions to global conflicts. Furthermore, perpetrators of terrorist acts have often mentioned target countries’ foreign policy as motivation for their crimes (e.g., Bartlett et al., 2010; Abbas & Siddique, 2012; O’Callaghan, 1999). Moreover, in multiple studies Western Muslims showed a general understanding and sympathy for political grievances that lead to some individuals resorting to violent extremism (Abbas & Siddique, 2012; Hamm, 2009; McCauley & Scheckter, 2008; Mythen et al., 2009). This again emphasizes the crucial role of foreign policy in the justification and motivation of terrorist acts by Western Muslims.

The systematic disadvantages experienced by Western Muslims lead to feelings of frustration and injustice, regardless of whether experienced first-hand or not, and contribute to the ‘us versus them’ mentality and the use of violence. The injustice done to the world-wide Muslim community as a result of Western foreign policies seems to be a large source of these feelings of frustration and resentment.

Personal Characteristics

Whereas the initial focus in the psychology of terrorism seemed to be solely on individual personality–the mentally abnormal terrorist -, the current focus seems to be (almost too strongly) solely on environmental factors, such as systematic discrimination, relative deprivation, and foreign policy (King & Taylor, 2011). Although the stereotype of the Islamist terrorist as a mentally ill individual has rightly been discounted (Silke, 2008), this does not mean that personal characteristics should be dismissed as factors possibly contributing to violent radicalization. So far, the exact role of personal characteristics in contributing to violent radicalization has not been delineated, thus, its further examination is needed. Personal characteristics can provide a plausible explanation for why only a small minority of Western Muslims radicalize. Many Western Muslims are exposed to the same terrorist propaganda, systematic disadvantages, and identity crises, but relatively few of them revert to terrorism. Personal characteristics can help to determine whether exposure leads to violent radicalization, explain why not all vulnerable individuals take the violent route, and inform counterterrorism programs.

Psychology of terrorism focused recurrently on thrill-seeking and adventurousness, traits often associated with Western terrorists (e.g., Bartlett et al., 2010). This characteristic seems not unique to Muslim terrorists, as terrorists and violent radicals from different organizations have equally referred to the thrilling and exciting attraction of joining their particular cause (Cottee & Hayward, 2011). Sensation-seeking is strongly intertwined with the facts that i) most individuals who join terrorist groups and execute attacks are young and male (Silke, 2008) and ii) about a quarter of all European jihadists have a criminal record (Bakker et al., 2006). Sensation-seeking as a trait is robustly correlated with delinquency in adolescence (Mann, Kretch, Tackett, Harden, & Tucker-Drob, 2015). Unfortunately, literature regarding the role of sensation-seeking in potential Western Islamist terrorists is scarce, and more research on the topic is required to determine the prevalence of this trait in Western Islamists and whether any causal link between the trait and the execution of terrorist acts can be established.

Another characteristic relevant to violent radicalization is narcissism (Victoroff, 2005; Alderdice, 2009). Narcissism is characterized by a sense of grandiosity, combined with a strong need to obtain attention and admiration from others (Thomaes, Brummelman, Reijntjes, & Bushman, 2013). In a study examining determinants of susceptibility for adopting radical belief systems in Dutch Muslim youth, Doosje and colleagues (2013) state that individuals from radical groups are inclined to use violence when their ego is threatened. The results of the study show that perceived in-group superiority is the best predictor of attitudes towards violence displayed by other group members, and was significantly related to violent intentions. This is in line with an earlier proposed narcissism-aggression link formulated by Baumeister and colleagues (1996; see also Thomaes et al., 2013). These findings imply that the presence of narcissistic traits in individuals is predictive of whether the individuals express their grievances in a violent manner. However, Bakker (2006) did not find any proof that the terrorists in his sample suffered from pathological narcissism. The emphasis in Bakker’s study is on psychopathology, which reflects the initial bias in terrorism research. Although in the context of lone wolf terrorism the contribution of individual character traits and psychopathology to violent radicalization has been discussed extensively, this focus is not justified especially when it comes to group-based terrorism (Corner & Gill, 2015). A more balanced approach to conceptualizing the determining factors of violent radicalization should include examination of ‘normal’ psychological variables, such as personality traits. Narcissism does not necessarily need to be seen as a form of psychopathology; indeed, many approaches cast narcissism as a dimensional trait which is expressed to a certain extent in everyone (Thomaes et al., 2013). It seems plausible that feelings of collective humiliation (due to foreign policy, unequal opportunities, etc.) contribute to engagement in violent behaviours by individuals who show higher levels of narcissistic traits. The literature on narcissistic traits in violent Western radicals is scarce; so far, research seems to have mainly been focused on Middle Eastern terrorists (Merari, Diamant, Bibi, Broshi, & Zakin, 2009; Miliora, 2004).

Research on personal characteristics contributing to violent radicalization is scarce. The contributing role of thrill-seeking in the engagement in terrorist behaviours seems plausible, as it is a recurrent theme in motivations mentioned by terrorists. The possible contributing role of narcissistic personality traits also seems tenable, considering the empirical evidence for a link between narcissistic traits and aggression in individuals. However, future research is needed in order to determine the extent to which these personality characteristics contribute specifically to violent radicalization in Western Muslims. Furthermore, research into other possible traits is required in order to fully elucidate which individuals are at a higher risk of joining terrorist organizations.


Another possible factor contributing to Western Muslims joining extremist Islamist organizations may be empathy (Awan, 2008). The exact role of empathy, however, is not completely clear based on current evidence. On one hand, the execution of violent attacks on innocent civilians seems to imply an absence of empathy. On the other hand, the fact that the suffering of Muslims abroad plays a major role in violent radicalization (see above) emphasizes the presence of empathy in terrorists. Indeed, it seems that empathy for the Ummah (the world wide Muslim community) acts as a primary motivation for the holy war waged by Muslim extremists (Nilsson, 2015). The deprivation experienced by Muslims worldwide, thus, not only leads to feelings of anger, frustration, and injustice, as mentioned before, but also to empathy among Muslims who are not experiencing these sufferings themselves (Awan, 2008; Van San, 2015). It is crucial to mention that the current paper focuses exclusively on Western Muslim terrorists attacking in the West. This focus is very different from investigating Muslim terrorists attacking in Muslim-majority countries, where the majority of victims are Muslim.

One way in which empathy for the suffering Muslim populations could be expressed is through suicide terrorism. Although this comparison might almost seem immoral, suicide terrorism can be seen as a form of altruism. Individuals committing the act put the goals of the collective before their own wellbeing (Awan, 2008). When studying Palestinian suicide terrorists, Pedahzur and colleagues (2003) found altruistic characteristics in these individuals and emphasized the strong component in the individuals’ perception of the relationship between them and their society. Similar signs of altruism are apparent in Western terrorists, as the plight of Muslim populations abroad is mentioned countless times by violent radicals (e.g., Bartlett et al., 2010; Abbas & Siddique, 2012; O’Callaghan, 1999). Perhaps altruistic characteristics or motivations are more prevalent in Western home-grown terrorists, as these individuals often haven’t even experienced poor living conditions the way, for instance, many of the Palestinian terrorists have. Yet, Western terrorists seem to be just as ready to endanger or even end their own life for the sake of their fellow Muslims. Further research is needed to confirm this hypothesis.

One aspect of terrorist organizations that is often overlooked and seems to be polar opposite to the stereotype of the coldblooded terrorist, is the strong sense of brotherhood that many individuals experience in these organizations (Nasiri, 2007; Nilsson, 2015). Indeed, friendship and kinship are recurrent influences in the path towards violent radicalization and terrorism (Hamm, 2009; Bakker, 2006). To demonstrate the extent to which the friendship between members of terrorist organizations plays a role in their engagement in violent behaviour, Cottee and Hayward (2011) draw a comparison with combat soldiers. In both groups (combat soldiers and terrorists), the permanent threat of capture or death strengthens the bonds within the group and creates a powerful sense of identity and in-group love among members (Cottee & Hayward, 2011). With this comparison, they emphasize that no matter the cause of one’s engagement in any type of war, eventually, ‘Individuals don’t simply kill and die for a cause - they kill and die for each other’ (Cottee & Hayward, 2011, p. 973).

The strengthening of in-group ties and the resentment towards the out-group have been discussed, but how can these processes contribute to the engagement in violence against innocent civilians? Doosje and colleagues (2013) emphasized the role of perceived distance between oneself and individuals from the out-group. They showed that perceived distance predicts both the support for Muslim violence committed by others as well as the own intention to use violence. Perceived distance was defined as a psychological detachment from out-group members, which could be rooted in a general resentment towards Western society. One aspect of terrorist ideologies that could have an effect on this dehumanization of the out-group is the Manichean worldview that is often represented by violent radicals and terrorists (Miller, 2013). Such a worldview essentially separates reality into good and evil. Perhaps this point of view enables the terrorist to justify the killing of innocents by using the label ‘evil’ on anyone and everyone who does not conform to their particular belief system.

There seems to be a presence of empathy in Islamist terrorists when it comes to in-group members, as shown by the presence of friendship and kinship in terrorist organizations, and the willingness to endanger the own life for the sake of the collective. On the other hand, the killings of innocent civilians points to an absence of empathy when it comes to out-group members. The increasing distance between oneself and the individuals of the out-group, as well as the black-and-white worldview often depicted by extremist ideologies, explain the contrast of altruistic tendencies towards the in-group versus extremely violent propensities towards the out-group. Future research is needed to clarify the exact role of empathy as a contributing factor to violent radicalization in Western Muslims.


With the rising numbers of Western Muslims joining insurgencies abroad and a, therefore, possibly greater threat of returnees planning to engage in domestic terrorism, research in this area is crucial to the wellbeing of the Western population. The current paper attempted to provide insight into the factors contributing to Western Muslims joining terrorist organizations and engaging in terrorist violence in the West (for a summary, see figure 1). Strong evidence emphasizes the role of some factors, such as identity crises and relative deprivation. For instance, Bartlett and colleagues (2010) found that terrorists, radicals, and young Muslims had all experienced some degree of societal exclusion, had a distrust of government, a hatred for foreign policy, many felt a disconnection from their local community, and many have had an identity crisis of some sort. The influence of these factors can be altered, for instance by nation-wide programs encouraging multiculturalism, and by providing assistance to minorities (in this case Western Muslims) struggling to find their place in the occupational world. The solution for societal problems related to relative deprivation and identity crises should be implemented on a large scale. The damage done by Western foreign policies in Muslim-majority countries needs to be not only acknowledged, but also further prevented if any more Western Muslims are to be steered away from militant Islamism. If it weren’t for Western involvement in these countries, there is no doubt that the narrative of militant Islam and its hostility towards the Western world would be weakened significantly.

There is a lack of research into the more individual and personal factors contributing to the violent radicalization of Western Muslims. Because these factors should not be neglected, this paper proposes multiple ways in which personal factors could have an influence on violent radicalization, in an attempt to encourage future research in academic counter-terrorism. The possibility of narcissistic and/or sensation-seeking traits playing a role in violent radicalization seems plausible and requires further examination. The role of empathy seems to depend on group-dynamics: on the one hand, terrorist individuals are willing to put the wellbeing of the collective before their own life, showing a sense of empathy, possibly even love, towards their in-group. On the other hand, however, the distance between the individual and out-group members seems to be so grave that the individual is able to justify the killing of innocent civilians. Delineating personal characteristics and empathy as contributing factors can help inform intelligence agencies about individuals at risk of joining violent radical groups.

The current paper emphasizes the variety of factors that contribute to violent radicalization. Future research should focus on clarifying the role of personal characteristics and empathy, as well as on exploring other factors possibly contributing to violent radicalization in Western Muslims. As was iterated before (Bakker, 2006), there is no single Islamist terrorist profile. It will be futile to try and predict terrorism in individuals who may have joined terrorist organizations. That does, however, not mean that there is no way to prevent terrorism and to reduce risk factors. Especially situations, in which the Muslim population in the West is systematically disadvantaged, can be altered to reduce the sense of threat many Muslim communities experience. Weakening the idea that the Muslim population, or Islam in general, is under attack will reduce the strength of the Jihadi narrative and contribute to the prevention of violent radicalization in Western Muslims. By working towards a comprehensive account of terrorist behaviour, the different factors found to be relevant can help guide international prevention programs and inform intelligence agencies about individuals who are at a higher risk of joining terrorist organizations.

About the Authors

Khouwaga Yusoufzai is currently a graduate student with a Bachelor’s degree in Psychology, obtained at Maastricht University, the Netherlands. Having fled the war in her native country Afghanistan at the age of two with only part of her family, the phenomenon of political violence and Islamist terrorism has continued to impact her throughout her life, sparking an interest in the dissection and explanation of terrorist behaviour.

Franziska Emmerling (née Dambacher) is currently a Niels Stensen postdoctoral fellow at the Department of Experimental Psychology and the Oxford Center for the Study of Intergroup Conflict at the University of Oxford, UK. After finishing her studies in psychology and theology at the University of Trier, Germany, and Sophia University Tokyo, Japan, she worked at the German Institute for Psychology of Religion investigating, among other things, New Religious Movements. In 2014, she completed her PhD in Cognitive Neuroscience at Maastricht University, where she explored the neural correlates of inhibitory processing and aggression. Ever since her work in the field of social neuroscience focuses on the biological, neural, and social factors underlying the development, establishment, and behavioral consequences of conflict.


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