A New Age of Terror? Older Fighters in the Caliphate
May 4, 2017
Abstract: Historically, terrorists have overwhelmingly been young adults. Direct involvement in terrorist attacks is associated with people in their 20s and 30s, with those in leadership positions slightly older (30s and 40s). The composition of the so-called Islamic State, however, defies the idea of even a generic demographic profile. While the Islamic State now manufactures child soldiers, preliminary evidence suggests an emerging and increasingly aggressive role for older adults (aged 60 and beyond), especially as suicide bombers. The Islamic State has produced not only the youngest suicide bombers in history, but now also the oldest. As pressure intensifies on the movement, this trend will likely continue.
On March 22, 2017, Khalid Masood killed four people and injured over 50 in the heart of London. Masood drove his vehicle into pedestrians on Westminster Bridge before crashing the car outside the British Parliament. He then stabbed a police officer who subsequently died of his wounds. Armed officers shot Masood dead before he could enter the Parliament building.
Questions immediately arose as to whether Masood was part of a cell or had acted alone. The next day, via its Amaq media service, the Islamic State issued a statement claiming Masood as a “soldier … executing the operation in response to calls to target citizens of coalition nations.”1 Masood appears to have been known to the British security services as early as 2010 but “dropped off the radar” before the London attack seven years later.2
Two opposing narratives quickly emerged regarding Masood’s radicalization. Some insisted Masood fit the standard profile of a British or European supporter of the Islamic State: a male Muslim convert with a history of anti-social behavior, including violence, and a criminal record.3 The second narrative, however, suggested Masood was an atypical Islamic State-inspired terrorist. One of the main reasons was due to his age. At the time of the attack, Masood was 52— a whole 25 years older than the typical violent extremist in the United States charged with offenses related to the Islamic State (i.e. either involved in plots at home or traveling/attempting to travel abroad).4
A New Age of Terror?
In one of the most cited efforts to profile terrorists, Charles Russell and Bowman Miller5 in 1977 described the average terrorist as “likely to be single, male, aged between twenty-two and twenty-four.” In a study of over 400 Italian female terrorists, Leonard Weinberg and Bill Eubank6 found active members to be mostly in their 20s. Paul Gill and John Horgan7 examined 1,240 cases of IRA membership over a 30-year period, discovering that most were in their early to mid-20s. The same finding emerging from Marc Sageman’s8 sample of over 100 jihadi terrorists worldwide, while Emily Dyer and Robin Simcox’s9 2013 study of 171 al-Qa`ida members also found that over half were under 30 at the time of their offense.
As expected, there are outliers. In cases of lone-actor terrorists of all ideological stripes,10 a higher mean age (33) exists for those who perpetrated or engaged in acts of terrorism. But demographic profiles of terrorists across time, place, and context otherwise point to the same conclusion—terrorism has predominantly been a young person’s game, with the clear majority engaging in their 20s.11
Differences emerge, however, in research that disaggregates terrorist leaders from followers. In studies across a variety of groups, leaders are older. Thomas Strentz’s12 analysis of American domestic terrorists in the 1960s and 1970s found that while followers were aged 20-25, leaders ranged from 25-40. Usama bin Laden was 44 at the time of the 9/11 attacks, and Abu Musab al-Zarqawi, the former leader of al-Qa`ida in Iraq, was 40 when he was killed in 2006. A leader of the Greek 17 November movement, Alexandros Giotopoulos13 was 58 when captured on a remote Aegean island, and several figures in the Provisional Irish Republican Army occupied leadership positions well into their 60s and 70s.14
Less frequent has been the involvement of older adults in committing acts of terrorism. Notable examples include 60-year-old Somali-Norwegian Abdullahi Abdulle, the oldest suicide bomber deployed by al-Shabaab to date.15 In Ireland, 66-year-old Donal Billings16 was convicted in 2011 of planting a bomb on a bus to coincide with a visit by Queen Elizabeth to Ireland. In the United States, 88-year-old white supremacist James Von Brunn17 shot and killed a security guard at the Holocaust Memorial Museum in Washington, D.C., making him the oldest lone-actor terrorist so far. In the U.S. state of Georgia, four members of an extreme right-wing group were arrested in 2011 for plotting a “biological weapon attack on American cities including Atlanta.”18 The four men ranged in age from 65 to 73.19
An area deserving of more research is how age correlates not just with broad roles (e.g. leader versus follower) but also with type of tactical engagement. Until recently, the oldest male suicide bomber was Rabah Bechla, aged 63 when he drove a truckload of explosives into a United Nations building in Algiers in December 2007,20 but the oldest confirmed suicide bomber was 64-year-old Fatima Omar An-Najar,21 a Palestinian grandmother (and widow) who blew herself up near Israeli soldiers in Gaza in 2006.
New data on Islamic State fighters suggests the need, not for the first time, to revise some commonly held assumptions about terrorists.
Older Adults in the Islamic State
Most implicated in Islamic State terrorism from western countries (that is, both those who have attempted to engage in local activities and those who have traveled or attempted to travel overseas on behalf of the Islamic State) are between 20 and 30 years old.22 According to a George Washington University study,23 the average individual implicated in Islamic State terrorism in the United States is 26 (recently revised to 27).24 Equally comprehensive studies of Islamic State foreign fighter registration documents conducted by the Combating Terrorism Center and the New America Foundation have found that the average fighter at the time of joining the Islamic State was 26 to 27 years old, and according to the New America Foundation’s Nate Rosenblatt was “single, had traveled to less than two foreign countries, had the educational equivalent of a high school degree, had basic religious knowledge, reported no previous fighting experience, and had the professional equivalent of someone between an unskilled laborer and a blue-collar worker.”25
Looking even more broadly, foreign fighters in the Islamic State examined by The Soufan Group26 find “most … in their 20s, but some [are] much younger.” This last point is significant. If anything, recruitment to the Islamic State has skewed even younger as of late. In early 2017, Robin Simcox27 highlighted how the group has exerted significant effort to persuade adolescent and pre-adolescent boys and girls in various ways to carry out acts of violence in the West. What is remarkable about such cases is how children engage in roles once presumed accessible only to adults.
Yet, evidence for another demographic shift may be emerging. New data obtained by the authors via the Islamic State’s preferred encrypted platform Telegram suggests that membership has expanded to include both the very young and the very old. The first appearances of older adults in the data collection was Sheikh Abu Ali al-Anbari, whose death was announced by the Pentagon on March 25, 2016, and was featured in al-Naba magazine a few months later.28 Sheikh Abu Ali (whose real name is reportedly Abdulrahman Mustafa al-Qaduli29) was a preacher and governor who purportedly traded in his leadership position to become a frontline fighter and died on the border between Syria and Iraq.30 He was likely 59 years old at the time of his appearance in al-Naba, and he was considered a likely successor to Abu Bakr al-Baghdadi.31
Since then, the Islamic State has begun to use older adult suicide bombers and suicide car bombers with increasing frequency over the past six months, and as such, the group is recruiting frontline fighters across the entire spectrum of human development.
Drawing from the expanding database of Islamic State members and activities, the authors have so far identified 27 older adults eulogized in the Islamic State’s propaganda channels. In many western countries, 65 is the normal starting point for what is characterized as “old,” though it is common for developmental researchers to distinguish ‘young’ old (i.e. 60-69) from other categories (e.g. ‘old’ old, or 80 and beyond). Here, the authors characterize older adult as 60+.
Eulogy images were collected primarily from the Islamic State’s semi-official news agencies Amaq, Nashir, and Dabiq as part of their ‘breaking news’ output. The collection process involved downloading the images from Islamic State Telegram channels, collecting them for insertion into a database, and then coding them. Data collection began in August 2016, and the current dataset runs until March 31, 2017.
Downloaded images were initially coded based on information included in the eulogy in the form of a chyron describing the individual as a martyr, a self-martyr, inghimasi (commando), a foot soldier, or with the simple Arabic benediction “May God accept him.” This phrase reliably designates a person as a martyr by the Islamic State. These individuals comprise those who have actively fought, rather than killed as non-combatants per se.a
If the information provided by the media agency specified self-martyr (suicide bomber or istishhad) but the individual was pictured next to or inside a vehicle, the authors coded them as a VBIED (Vehicle-Borne Improvised Explosive Device) operator, or suicide car bomber. To strengthen the validity of the data, the authors examined video material from the Islamic State media’s special drone unit(s). The authors could validate the existence and identities of specific VBIED operators in their sample by watching the entire operation—from the image of their pre-attack pose posted to the network to the actual explosion. The media division often added branding to the videos, and a small window with the bomber’s photo was presented in the corner of the screen. Any individual not photographed in a vehicle in the static images released by the Islamic State but who appeared in a martyrdom operation video driving a car/truck bomb was recoded as a VBIED operator upon the discovery of new information. In a video, “Procession of Light II,” released by the Islamic State on April 9, 2017, two additional older adult suicide bombers are depicted. However, at the time of writing, neither individual had yet been verifiably associated with an official eulogy. Consequently, they are excluded from the authors’ dataset. For four individuals in the dataset, the precise nature of their deaths remained unspecified, although they were designated by the group as martyrs. These are coded ‘unspecified martyrs’ with the understanding that the detailed videos of their operations may well eventually appear on the channels or chat rooms.
Two of the authors have previously published results in this publication about the Islamic State’s use of children,32 and this study largely reproduced the previous methodology for collecting images in which the Islamic State eulogized individuals as “martyrs” using the phrase “may God accept him.” These images provided additional information about the location of the attack (which regional media office branded the attack), ranging from the individual’s kunya (nom du guerre), nationality, location of death, and often target type, as well as additional information gleaned from visual analysis. The individual’s kunya was used as a proxy for nationality. For example, al-‘Iraqi denoted that they were Iraqi and al-Suri that they were Syrian. Recently, more specific locations have been used—for example, al-Maslawi meaning that the attacker originated from Mosul.
In addition to the images posted on Telegram, videos of attacks produced by the Islamic State’s Al-Hayat media center and other outlets allowed the research team the opportunity to glean additional information about the attack, and differentiate the more general category of suicide bombers from suicide car bombers or foot soldiers. This allowed for simple data triangulation of the attacks as well as accurately determining the length of time between, for example, the initial posting of the eulogy image and the video release of the suicide car bomb attack (an average of six to eight weeks). Eulogies were further validated by comparing against the Islamic State’s ‘daily reports,’ the English-language statements issued every day to communicate the execution of operations by the group. Finally, the authors used basic intercoder reliability checks for their classification such that five people (the authors) independently coded each image, reconciling discrepancies in project group meetings.
From August 2016 to March 31, 2017, the authors found 27 older adults, aged 60 and older, eulogized by the Islamic State.
The location of the deaths indicated that most of the older martyrs were deployed in Nineveh province. Fifteen died in Nineveh (Mosul), five in Aleppo, three in Diljah, with one each in al-Baraka, al-Janub, Raqqa, and Sinai.
The origins of the fighters were such that 14 were Iraqi, four Syrian, two Iraqi/Syrian designated as Ansari, two Egyptian, one Jordanian, one Tajik, one Kazakh, and two currently unknown.
The Arab online news source Al Masdar News reported in March 2017, via research conducted by its contributor Ibrahim Joudeh, that 80 percent of suicide bombings in recent months were cumulatively perpetrated by both children and elderly recruits.33 In December 2016, the Islamic State paired an older man, Abu Salman al-Tajiki, with one of its youngest bombers, a 10-year-old Yazidi boy named Abu Khattab al-Sinjari.
With the battle of Mosul, the Islamic State appears to have deployed older adult bombers with greater frequency. A systematic verification by the authors suggests that in January 2017, there were 35 adults, 51 children and youth, and three older adults eulogized as martyrs; in February 2017, there were 32 adults, 26 children and youth, and four older adults; and in March 2017, there were 34 adults, 23 children and youth, and 11 older adults. The number of older adults has increased, but in slight contrast to Al Masdar’s claims, the authors’ estimates suggest suicide bombing operations featuring seniors, youth, and children never exceeded 60 percent of the total.
The earliest appearance of older adults as bombers was in August 2016. Their deployment did not appear to gain momentum until December 2016. Though the numbers are small, these older bombers are gaining notoriety among members and supporters alike.
Of the 27 cases, 16 died detonating themselves in a vehicle-borne IED, two died as foot-soldiers, one as an inghimasi (commando), one was killed by a drone, three were described as istishhadi (self-martyrs or suicide bombers), and four were undesignated but listed as martyrs. (See Figure 4).
Some interesting perceptions exist of these older adults within the Islamic State itself. In an homage posted by Islamic State supporters about these older operatives—and using a montage of several of the bombers in the dataset—they included the following phrase: “In loving memory of our old men who’s [sic] legs became heavy in old age, who were the real hero’s [sic] (May Allah Accept Them).” (See Figure 5).
The older adults are venerated by the Islamic State as sources of emulation, while they have, in comparison, mocked men (derisively referring to them as “Sheikhs”) on holiday in Turkey. (See Figure 6).
Other supporters contrast older men like ‘Abu Fawaz’ (see Figure 7), who are willing to sacrifice themselves for the caliphate, with men in other countries who are unwilling to make a comparable sacrifice. To this end, on the Dabiq Telegram news channel, Islamic State supporters posted an image that venerates the older bomber and mocks the other man, who is smoking (i.e. engaging in haram activity).
The comment in Figure 7 states: “Contrasting between those true fighters (who fight the evil doers) and those who bow down seeking the Rafidi (rejectionist’s) approval.”
Furthermore, some portrayals of older adults in combination with children reinforces the ‘shaming’ function to mobilize additional recruits. On April 4, 2017, the image shown in Figure 8 appeared in the Islamic State’s Dabiq channel on Telegram.
Figure 8: In this image, posted to the Dabiq channel on Telegram on April 4, 2017, the Islamic State contrasts its youngest and oldest bombers with a caption that reads: “Our youth see glory in war and our elders are experienced warriors. Death to you Oh America, A nation (ummah) whose youth and elders are racing towards death and sacrifice will not be defeated.”
The same day these images were released on Telegram, a spokesman for the Islamic State clarified the group’s view about the involvement of older adults in operations. In an audio speech, Abu al-Hassan al-Muhajir proclaimed,34 “The martyrdom-seeking attacks have not been restricted to youths, but include elders, as well. Everyone makes haste and races with his fellow. They are youths who see heroism in death. Elders with grey hair are seen in the battlefield.” Decrying the United States’ efforts to “eliminate the mujahideen,” he continued, “All that you worked for went down the drain and your endeavors were halted. Here they are, those who saddle the steeds of sacrifice—their explosives-laden vehicles—and those who fight on the frontlines with grey beards and who long for having it stained with blood.”
The Islamic State has found a new use for its oldest members, which serves several simultaneous functions—from tapping into an additional pool of recruits when faced with increasing external pressure to transforming obvious physical limitations into the efficient delivery of bombs to serving propaganda functions like those fulfilled by the Islamic State’s use of children—namely, shaming and goading any remaining non-participants into action.
Though initially featured in Telegram messages and in the occasional video, the Islamic State has begun to celebrate older adults much more systematically. The group’s hour-long video “Procession of Light II,” released on April 9, 2017, features older adults and young children prominently, with children filmed helping older adults prepare for their martyrdom operations. The viewer is also shown older adults preaching to children about what they need to do. One of the older adult martyrs initially discovered via Telegram images, Abu al-Yaman al-Urduni, is celebrated in this recent video. He is revealed to be physically disabled, shown in a wheelchair and lifted into the bomb-laden vehicle by his Islamic State comrades.
The data confirms that most of the older operatives who carry out attacks die in suicide bombing operations. The use of older adults in this way is a new development. Whether it continues remains to be seen, but several reasons may explain their emergence. The Islamic State may be running low on younger suicide bombers in general. According to U.S. commanders, over 2,000 Islamic State fighters were killed in the battle of Mosul (which started on October 17, 2016) in the months leading up to the Islamic State’s tactical innovation of using older combatants.35 The majority of the older adult martyrs died between December 2016 and March 2017. This suggests older adults are used simply because of a shortage in fighters overall.
Related, but distinct, it may also be that older bombers are used as a substitute for younger bombers redeployed to other activities (or areas), perhaps as exigencies warrant. It is equally conceivable that when faced with mounting pressure in areas currently under Islamic State control, older adults simply join the fray in a last-ditch effort to maintain or project dominance. From a group perspective, faced with impending defeat, the opportunity to join in is simultaneously an opportunity for older adults to seize upon the rewards they believe are granted to martyrs in the afterlife. In “Procession of Light II,” al-Urduni says to the camera and his young children: “So I love you, but I am leaving. By God I want to stay with you and see you growing up. I also love to fight, I love jihad. But I don’t know whether there will be another opportunity or not. I ask Allah to forgive me, and to accept me, and to make me an example for the believers.”
If other family members are already engaged in similar behavior, the pressure to act may be even greater for the older adult. But there are also subtler influencing factors likely at play. At an individual level, psychological development for older adults is typically characterized as a period of contemplation and retrospection.36 Looking back on one’s life can be fraught with risk. If doing so results in a person feeling that they have lived a full and meaningful life, then it helps them prepare for death in a productive, accepting way. If, however, a person instead feels that their life has been unremarkable, unsuccessful, and/or unsatisfying, such a realization can instigate a crisis. If unresolved, this quickly turns into despair and depression. Faced with a meaningless and largely insignificant death, what better opportunity for redemption and reward in the afterlife (as well as being immortalized in propaganda) than embracing martyrdom?
With up to 40,000 foreigners from over 120 countries joining locals in Syria and Iraq, the Islamic State boasts astonishing numbers in their ranks. Surely then, a few dozen older adults would not register as anything beyond an insignificant development? But it is worth recalling that the same assumptions surrounded initial reports in 2014 of a ‘few’ children appearing in Islamic State operations. Now, children routinely fight alongside adults, and child suicide bombers number in the hundreds.37
Using intuitive logic, observers can expect the use of older adults to continue. Ordinarily, jihad (used here in the sense of holy war) was reserved for men of military age. The legal doctrine of “defensive jihad” was designed for extraordinary circumstances that would theoretically permit nontraditional operatives (i.e. women, children, the elderly) to enter the fray. As is widely recognized, the Islamic State has discarded any of the usual norms of conflict, not just in terms of its own conduct, but also in terms of how children and the elderly are now recruited for frontline operational duty. Women are the only group still excluded from the individual obligation to perform ‘jihad’ for the Islamic State.b
As the Islamic State loses territorial control, it likely perceives itself on the defensive, no longer able to enjoy its aggressive expansion from just a few years ago. Furthermore, if the Islamic State has come to the realization that it may actually be losing, the concept of “defensive jihad” is likely to be fully brought into its strategic and tactical decision-making, at least locally. Under those conditions, everyone is obligated to participate—not just the men of military age.38 It seems inevitable, therefore, that the group will continue to seek the mobilization of children, adults, and older adults to its cause. CTC
John Horgan is a professor in the Global Studies Institute and Department of Psychology at Georgia State University. His most recent book, The Psychology of Terrorism, is now in its second edition. Follow @drjohnhorgan
Mia Bloom is a professor of Communication at Georgia State University and author of Dying to Kill: The Allure of Suicide Terror and Bombshell: Women and Terror. Follow @miambloom
Chelsea Daymon is a Ph.D. candidate in Communications and a presidential fellow in the Transcultural Conflict and Violence Initiative at Georgia State University. Follow @cldaymon
Wojciech Kaczkowski is a Ph.D. candidate in Community Psychology and a presidential fellow in the Transcultural Conflict and Violence Initiative at Georgia State University. Follow @WojKaczkowski
Hicham Tiflati is a senior research associate at Georgia State University. Follow @HTiflati
[a] In one case, an individual named Ahmed Hussein was killed in a drone attack while working as the chief engineer of the Euphrates Dam. The eulogy did not include the benediction, and so he did not feature in the authors’ database as a fighter for the Islamic State. While in the strictest sense of the word, a civilian casualty may be considered a martyr if they have been killed by the enemy (such as in the Palestinian-Israeli conflict in which casualties are given the status of martyr (shahid) but not self-martyr (istishhad)). Nevertheless, in its breaking news posts to social media and the eulogy posted by Amaq news, this phrase was absent for Ahmed Hussein. An older leader of the Islamic State in the Sinai Peninsula, Salaama Abu Adhan al-Tarabin was likewise killed by a drone, yet Sinai’s media office included the phrase “May Allah accept him” in his eulogy. Additionally, he was given the special designation of “caravan of martyrs.” Thus, the way in which someone dies does not in itself determine whether the Islamic State considers him/her to be a martyr. The authors concluded that the benediction “may Allah accept him” is reserved for its frontline combatants. In fact, several in the authors’ sample were designated as part of a select martyr brigade in which “caravan of martyrs,” written in ornate calligraphy, was added to images in post-production.
[b] When the Islamic State’s predecessor, al-Qa`ida in Iraq (AQI), faced mounting pressure in the mid-2000s, the group began to use women in attacks. Given that the Islamic State is now using older men, it would not be entirely unexpected if the group eventually deployed women in this role. See Nelly Lahoud, “The Neglected Sex: The Jihadis’ Exclusion of Women From Jihad,” Terrorism and Political Violence 26:5 (2014): pp. 780-802.
 Amaq News Agency, breaking news statement via Telegram, March 23, 2017.
 Hannah Summers, Ewen MacAskill, and Vikram Dood, “Westminster attack: Khalid Masood identified as potential extremist in 2010,” Guardian, March 26, 2017.
 Jason Burke, “Khalid Masood was a convert with a criminal past. So far, so familiar,” Guardian, March 25, 2017.
 “The George Washington University ‘Extremism Tracker’ – The Islamic State in America,” 2017.
 Charles A. Russell and Bowman H. Miller, “Profile of a Terrorist,” Terrorism: An International Journal 1:17–34 (1977).
 Leonard Weinberg and William L. Eubank, “Italian women terrorists,” Terrorism: An International Journal 9:241-262 (1987).
 Paul Gill and John Horgan, “Who Were the Volunteers? The Shifting Sociological and Operational Profile of 1,240 Provisional Irish Republican Army Members,” Terrorism and Political Violence 25:3 (2013): pp. 435-456.
 Marc Sageman, Understanding Terror Networks (Philadelphia: University of Pennsylvania Press, 2004).
 Emily Dyer and Robin Simcox, Al-Qaeda in the United States: A Complete Analysis of Terrorism Offenses (London: Henry Jackson Society, 2013).
 Paul Gill, John Horgan, and Paige Deckert, “Bombing Alone: Tracing the Motivations and Antecedent Behaviors of Lone-Actor Terrorists,” Journal of Forensic Sciences 59:2 (2014): pp. 425–435; Paul Gill, Lone-Actor Terrorists: A Behavioral Analysis (London: Routledge, 2016).
 Jeff Victoroff, “The Mind of the Terrorist,” Journal of Conflict Resolution 49:1 (2005): pp. 3-42.
 Thomas Strentz, “A terrorist psychosocial profile: Past and present,” FBI Law Enforcement Bulletin 57:13-9 (1988).
 Andrew Chang, “What happens to old terrorists?” ABC News, July 31, 2002.
 Richard English, Armed Struggle: The History of the IRA (New York: Oxford University Press, 2003).
 Ludovica Iaccino, “Former Somalian MP, aged 57, becomes al-Shabaab’s second-oldest suicide bomber,” Yahoo News, July 27, 2016.
 “Man sentenced over bomb on bus during Queen Elizabeth’s visit,” RTE News, December 15, 2016.
 “Guard killed during shooting at Holocaust museum,” CNN, June 10, 2009.
 Conor Friedersdorf, “Grumpy old terrorists? The FBI says 4 seniors plotted bio attack,” Atlantic, November 2, 2011.
 “North Georgia Men Arrested, Charged in Plots to Purchase Explosives, Silencer and to Manufacture a Biological Toxin,” FBI press release, November 1, 2011.
 Katrin Bennhold, “A grandfather’s suicide bombing puzzles Algerians,” New York Times, December 18, 2007.
 “Palestinian grandmother blows self up in Gaza,” NBC News, November 23, 2006.
 Lizzie Dearden, “ISIS documents leak reveals profile of average militant as young, well-educated but with only ‘basic’ knowledge of Islamic law,” Independent, April 21, 2016.
 Lorenzo Vidino and Seamus Hughes, “ISIS in America: From retweets to Raqqa,” Program on Extremism, George Washington University, 2015.
 “GW Extremism Tracker: The Islamic State in America,” George Washington University’s Program on Extremism, 2017.
 Brian Dodwell, Daniel Milton, and Don Rassler, The Caliphate’s Global Workforce: An Inside Look at the Islamic State’s Foreign Fighter Paper Trail (West Point, NY: Combating Terrorism Center, 2016). See also Nate Rosenblatt, “All Jihad is Local: What ISIS’ Files Tell Us About Its Fighters,” New America Foundation, July 2016, pp. 7-8.
 “Foreign Fighters: An Updated Assessment of the Flow of Foreign Fighters into Syria and Iraq,” The Soufan Group, 2015.
 Robin Simcox, “The Islamic State’s Western Teenage Plotters,” CTC Sentinel 10:2 (2017). See also Mia Bloom, John Horgan, and Charlie Winter, “Depictions of Children and Youth in the Islamic State’s Martyrdom Propaganda, 2015-2016,” CTC Sentinel 9:2 (2016).
 Al-Naba, #43 16 Dhul Qadah 1437, August 19, 2016, p. 8.
 Thomas Jocelyn and Bill Roggio, “Pentagon announces death of senior Islamic State leader,” Long War Journal, March 25, 2016.
 Michael S. Schmidt and Mark Mazzetti, “A top ISIS leader is killed in an airstrike, the Pentagon says,” New York Times, March 25, 2016.
 “Abd al-Rahman Mustafa al-Qaduli,” Counter Extremism Project, 2017. See also Daniella Peled, “Who was Abd al-Rahman Mustafa al-Qaduli?” Haaretz, March 25, 2016.
 Bloom, Horgan, and Winter.
 Paul Antonopoulos, “ISIS manpower shortage sees them relying on elderly, children in suicide operations,” Al Masdar News, March 3, 2017.
 “IS spokesman rallies fighters and challenges America in audio speech, calls on lone wolves,” SITE Intelligence Group, April 4, 2017.
 Michael D. Regan, “2,000 ISIS fighters killed in Mosul, US commander says,” PBS Newshour, December 11, 2016.
 See Erik H. Erikson and Joan M. Erikson, The Life Cycle Completed (Extended Version) (New York: W.W. Norton, 1998).
 Bloom, Horgan, and Winter.
 Onder Bakircioglu, Islam and Warfare: Context and Compatibility with International Law (London: Routledge, 2014), p. 74.