Abstract: Since September 2014, the Islamic State has been successful in persuading teenagers and pre-teens in the West to carry out attacks there. As of the end of 2016, there had been 34 such plots in seven countries, with civilians most commonly targeted and knives repeatedly the weapon of choice. In the majority of cases, the plotters were in direct contact with the Islamic State. The data also suggests that this problem is worsening; on average, there were two plots per month in 2016. Moreover, the Islamic State’s ideology, Manichean world view, use of social media, and online propaganda has a particular appeal to young people.
In September 2014, the Islamic State’s external operations emir, Abu Mohammed al-Adnani, called on the group’s Western supporters to carry out attacks against “disbelievers” using any method possible. The first person to take up the instruction, two days later, was an Australian teenager. Abdul Numan Haider was 18 years old when he stabbed two police officers in Melbourne before being shot and killed. The Islamic State praised the attack, labeling it a “direct result” of al-Adnani’s call to arms.1
Haider’s is not an isolated case. In the past two years, the Islamic State has inspired, and in some cases directed, teenagers and even pre-teens to carry out a series of terror operations in the West.a Europe’s youngest terrorist—a 12-year-old boy—was detained in December 2016 after attempting to bomb a Christmas market and town hall in Ludwigshafen, Germany.2
The ability to draw Western youth into Islamist terror networks is not unique to the Islamic State. One of the al-Qa`ida suicide bombers who struck the London transport network on July 7, 2005, Hasib Hussain, was 18 years old at the time.3 There are numerous other examples. Yet the Islamic State has had far more success in recruiting Western teens and pre-teens than any other terrorist group. In France alone, almost 2,000 teenagers are assessed by French officials to have been radicalized by the Islamic State, with a 121 percent increase between 2015 and 2016. At least 17 of its teenagers have been killed fighting in Syria or Iraq.4
The dissemination of its propaganda online is part of the reason the Islamic State has been able to find unparalleled success with this demographic group. The increase in social media platforms, their popularity with the millennial generation, and that same generation’s technological savviness in using them have all aided the Islamic State’s efforts. For example, according to one American survey, only two percent of individuals between 13 and 33 years of age do not use social media platforms.5 The Islamic State has not only disseminated its propaganda and ideology far and wide electronically, but it has been able to contact teenagers directly via social media platforms and, just as importantly, been contacted by them. One consequence of this has been the Islamic State’s use of messaging apps to encourage teenagers to plan attacks. Such plots have been described as being directed by the Islamic State via “remote-control.”6
The Islamic State has also had success in appealing to young girls. According to Germany’s Federal Office for Migration and Refugees, around half of all referrals for anti-radicalization counseling are for girls, with a significant increase since the end of 2014.7 Young women and girls have also volunteered to serve as brides to jihadis in Syria; approximately 600 Western females are believed to have made the journey.8
This article focuses on teens and pre-teens in the West (those aged between 12 and 19) that have become involved in Islamic State terrorism. It draws on data the author collected on all terror attacks and plots involving those in this age range that have emerged in the West and were claimed, directed, encouraged, or inspiredb by the Islamic State. Parts of the data relate to pending court cases. In such cases, all comment from the author hypothesizes that prosecution claims will be borne out, but this study does not explore the detail of any case or offer any judgment.
This study has identified 34 alleged or confirmed plots that took place in the period between al-Adnani’s call for attacks in September 2014 and the end of December 2016 (see appendix). Due to reporting restrictions on minors charged with crimes, extensive biographical details for these individuals are not always disclosed. However, using what information is publicly available, this study outlines the emerging trends.
Between September 2014 and December 2016, a total of 34 plots or alleged plots were organized by Islamic State-inspired or -directed teens and pre-teens. These 34 plots involved 44 teenage and pre-teen participants. The threat appears to be growing. In 2015, there were seven plots involving teenagers and pre-teens. In 2016, there were 24 (71 percent of the total). Therefore, there was an average of two plots per month involving teens or pre-teens in 2016, with nine plots uncovered in September alone.
Age and Gender
The mean age of these participants is 16.7; the median 17; and the mode 18. Of the 44 participants, 35 (80 percent) were male, and nine (20 percent) were female. By contrast, 96 percent of Islamist-related offenses logged in the United Kingdom between 1998 and 2010 were committed by males;9 in the United States, 95 percent of al-Qa`ida-related offenses between 1997 and 2011 were committed by males. 10 While these studies analyzed plots involving perpetrators of all ages and not just those involving teens and pre-teens, it does still seem clear that the Islamic State has sparked an uptick in young female participation in Islamist terrorist activity.
The 34 plots were directed at targets in seven countries: Australia, Austria, Denmark, France, Germany, the United Kingdom, and the United States. The country most commonly targeted was France, which has faced 11 plots (32 percent of the total amount). The next most commonly targeted was Australia (8 plots, or 24 percent), followed by Germany (7 plots, or 21 percent). All of the German plots and all but one of the French plots occurred in 2016, suggesting the threat to Europe from this type of terrorism increased significantly that year.
Authorities did not have prior intelligence of the planning of 11 plots (32 percent). On one occasion, that of the 12-year-old German Iraqi who planted two bombs in Germany, authorities were unaware of the plan yet the actual attack failed. The child placed a nail bomb at a Christmas market on November 26, which failed to detonate, and then another near a city hall on December 5, which a passerby noticed and reported to the police. Experts later judged it not to be viable.11
On another occasion, in September 2016, an 18-year-old Australian teenager was arrested after acting suspiciously near the Sydney Opera House. The teenager told police that, “I’m here because ISIS has instructed me to carry out an attack.” This was believed to be in relation to an Islamic State propaganda magazine that had been released days earlier, encouraging an attack in Australia and specifically referring to the Sydney Opera House. The teen was in possession of automotive fluid but not a viable explosive device.12
In all the other plots, the attacks were carried out. These occurred in Germany (on a further three occasions), France, Australia (twice) and the United States (twice). These led to two civilian deaths: Curtis Cheng, a civilian police worker in Sydney, Australia, in October 2015,13 and the Catholic priest Jacques Hamel in Normandy, France, in July 2016.14 They also produced 28 non-fatal casualties (15 in the United States, nine in Germany, and two each in Australia and France).
Civilians were the most common target of these plots. That was the case in 17 plots (50 percent) (five in France, four in the United States, three in Germany, two in Australia, one in Austria, one in Denmark, and one in the United Kingdom). Three of these plots on civilians—two in Australia, one in France—also targeted the police.
Including these three plots, the police were targeted on seven (21 percent) separate occasions (five plots in Australia and one in France and Germany). The military was the intended target on three occasions (once in the United States, once in the United Kingdom, and once in France). The U.K. plot also contained a component targeting civilians.
In the remaining cases, the target was not disclosed or had not been finalized by the perpetrator(s).
The weapon of choice in 12 (35 percent) of these plots was an edged weapon.c On 11 occasions, the weapon used was a knife. Indeed, a knife was used in six of the nine plots that were successfully executed, including in Jacques Hamel’s murder. One case involved the use of a machete (the stabbing of a Jewish teacher in Marseille).
Edged weapons were used alongside other instruments. A knife was used in conjunction with an axe during Muhammad Riyad’s attack against passengers on a train in Germany in July 201615 and was planned to be used alongside guns in a plot against a French military base in July 2015.16 A knife was used alongside a car in Sevdet Besim’s plan to run over and then behead a police officer in Australia in April 201517 and in Abdul Artan’s attack on students at Ohio State University in November 2016.18 In one example, a knife was used as a last resort, with Ines Madani attempting to stab a policeman while resisting arrest in September 2016. Madani was allegedly part of a cell suspected of planning a series of attacks, including the bombing of a train station in Paris. The plot was disrupted after a car belonging to Madani that contained five gas cylinders and three petrol tanks was allegedly discovered near Notre Dame Cathedral.19 Including the Madani plot, explosives were to be used in nine attacks, although only one of these was executed (against a Sikh temple in Essen, Germany, injuring three).20
Six cases involved the use of firearms. This included three cases in the United States, none of which came to fruition. There was also one failed plot involving a firearm in Australia and one in the United Kingdom. However, one of the plots saw a 15-year-old shoot dead an Australian police official in the Sydney suburb of Parramatta in October 2015.21
On nine occasions, the method of attack was either undisclosed or ultimately unclear due to the plot being insufficiently advanced.
Contact with the Islamic State
In 21 of the 34 plots (61.8 percent), the perpetrator or one of the perpetrators in a cell had been in known contact with the Islamic State. (See Figure 1). On 17 occasions, this contact took place only electronically, with encrypted messaging services such as Telegram proving popular. In eight of these cases, teenage perpetrators were in contact with the same man: a Syria-based French terrorist named Rachid Kassim.d These cases all occurred in France, between July and September 2016.
In only four cases (11.8 percent) had there been any known face-to-face interaction with Islamic State operatives. These all related to 2016 plots (three in Germany, one in Denmark).e
Of the 34 plots, it appears there are only seven cases (20.6 percent) where the perpetrators seemed to be acting truly independently—without an accomplice, fellow cell members, the involvement of an electronic guide from the Islamic State, or an undercover informant or agent. (See Figure 1). Three of these cases relate to the United States: Faisal Mohammed (November 2015), Mahin Khan (July 2016), and Abdul Artan (December 2016). Three are in Australia (Abdul Numan Haider, September 2014; Tamim Khaja, May 2016; and an unnamed teen, September 2016), and the other involved an unnamed teen in Marseille, France (January 2015).
Yet there are caveats to some of these cases. Several plotted on their own but were not “loners.”22 Khan had attempted to make contact with a terrorist based in Pakistan for guidance;23 Haider was associated with the notoriously extremist Islamic center Al-Furqan in Melbourne.24 Therefore, the primary terror threat cannot be said to come from teenage loners.
There are several likely reasons why teenagers tend to be more commonly involved in plots with others, as opposed to acting alone. Teenagers and pre-teens may be more vulnerable to peer pressure (both from adults or their peers), and they may require expertise from more experienced individuals or guidance from charismatic recruiters in order to fulfill their plans. However, it should also be remembered that terrorist plots involving individual actors of all ages whose offenses were not reliant upon or connected to any kind of network are actually exceedingly rare. In the United States, for example, between 1997 and 2011 such actors comprised four percent of all al-Qa`ida-related offense perpetrators.25
It is notable, however, that in five of these seven cases where individuals were acting autonomously and alone, their plotting went unnoticed. On four of these occasions, they were able to carry out their attacks (always involving an edged weapon and leading to a total of seven injuries). The conventional wisdom that so-called lone-wolf attacks using easily purchasable weapons are harder for authorities to detect and subsequently stop is backed up by the admittedly very limited dataset used in this study.
In 14 of the 34 plots (41 percent), youngsters worked in domestic cells with others who lived in the same country. Nine of these cells (26 percent) contained at least one adult. Five (15 percent) were comprised solely of other youngsters. The highest number of teenagers or children in any one cell was three—those responsible for bombing a Sikh temple in Essen, Germany, in April 2016.
Of these 14 plots involving cells, eight (24 percent) were also in contact with the Islamic State (six in electronic contact; two had some form of face-to-face contact). The other six (17.6 percent) had no contact with the Islamic State but took inspiration from their ideology. (See Figure 1).
Aspirant or Frustrated Travelers
Fourteen of the 34 plots (41 percent) involved individuals who had expressed an interest in traveling to Syria to join the Islamic State. Eleven plots contained ‘frustrated travelers’ who had made clear efforts to travel to the caliphate (or were suspected of doing so) but had been thwarted in their attempts (five plots in Australia, four plots in France, and two in Germany). The other three plots had seen individuals either express an interest in travel to Syria after carrying out the attack or it was unclear when exactly they wished to make the journey.
Both the murderers of French priest Jacques Hamel had tried to travel to Syria.26 One of the assailants, Adel Kermiche, was wearing a monitoring bracelet for precisely this reason, having tried unsuccessfully to travel on multiple occasions.27 In Australia, convicted Anzac Day terror plotter Sevdet Besim stated on his ‘martyrdom’ video: “At first, I wanted nothing else but to leave this country and live in the Islamic State, however after many complications with my passport, I realized this could not be done.”28
On two occasions, the Islamic State is known to have encouraged ‘frustrated travelers’ to carry out attacks at home instead. This was the case with a cell based in the south of France that then allegedly planned an attack on a military base in July 2015.29 It was also the case with “Safia S.” in Germany, although this case is more complex. Safia S. made it as far as Turkey before being collected by her mother, yet she had connected with Islamic State members while there who persuaded her of the need to carry out an attack in Germany rather than travel to Syria. Safia S. was also in electronic contact with another individual who provided advice on how to carry out her attack. She stabbed a policeman in Hanover in February 2016.30
There are other trends becoming apparent in these cases that should be monitored as more data becomes available. For example, there are multiple cases of parents alerting the authorities to increasingly radical behavior of their children. The parents of one of the Normandy church attackers did so as their son’s behavior became ever more extreme and as he attempted to travel to Syria.31 The mother of “Ismael K.,” who was part of a cell planning an attack on a military base in the south of France, had previously prevented her son from traveling to Syria.32 In the United States, it was the father of Justin Sullivan, a 19-year-old from North Carolina who aimed to carry out shootings on the Islamic State’s behalf with a semi-automatic rifle, who flagged his son’s sympathies for the Islamic State to the police.33
This illustrates how parents are clearly useful in identifying changes in behavior and possible violent leanings. However, these cases are not always black and white. Although Madani’s father reported her to French authorities,34 he himself had also been reported as an Islamist radical.35 Furthermore, Safia S.’s mother retrieved her daughter from Turkey but had also previously sent her to a mosque that put her in contact with notorious salafi clerics, which may have contributed to her radicalization.36
There were only two known converts to Islam among the teenage offenders: the North Carolinian Sullivan and an unnamed 16-year-old Danish girl, who planned to bomb two Copenhagen schools and worked alongside an individual who had fought with the Islamic State in Syria in order to do so. On paper, this is a disproportionately low amount: almost a quarter (23 percent) of individuals who committed al-Qa`ida-related offenses in the United States from 1997-2011 were converts. However, the low figure in this study should not be seen as surprising because converts in Islamist terrorist cases tend to carry out offenses later in life. With al-Qa`ida-related offenses, converts were significantly older (most commonly, age 32) at the time of charge than non-converts.37
There were five plots (15 percent of the total) perpetrated by refugees, all of which took place in 2016. One of these attacks was carried out by Abdul Artan, a Somali refugee who lived in the United States and injured 11 people in Ohio during an attack that the Islamic State later claimed was carried out on its behalf. The other four were in Germany in 2016, and all involved individuals in contact with the Islamic State. One case involved a refugee from Afghanistan—the July attacks on train passengers in Würzburg, Germany, by Muhammad Riyad.38
The other cases involved Syrian refugees. “Shaas al-M.” joined the Islamic State in mid-2013 and was trained by the group in Syria. He was arrested in March 2016 after authorities believed he had carried out reconnaissance on targets in Berlin on behalf of the group. He had allegedly informed the Islamic State he wished to take part in the attack and had also recruited another individual to fight in Syria.39 In September, “Mohamed J.” was arrested in Cologne, who was in contact with an Islamic State operative about constructing a bomb.40 In the same month, three Islamic State members (two of whom were teenagers) were arrested in Schleswig-Holstein. They had been based in German refugee shelters and gained entry into Europe thanks to the same smuggling network used by the Islamic State in the November 2015 Paris attack.41
The threat nexus linked to refugee flows, therefore, would appear be at least two-pronged. There are Islamic State operatives who have used the refugee flow to infiltrate Europe and those who become radicalized once they arrive in the West. This latter type of radicalization is made more likely by pre-existing radical networks. In Germany, for example, dislocated youngsters are moving to a new country containing a significant number of Islamic State sympathizers.
The Islamic State’s calls for attacks are increasingly resonating with radical-leaning teens and pre-teens in Europe. The Manichean appeal of the group’s ideology certainly plays a part in this appeal. Yet such has been the Islamic State’s success, the driving force behind its recruitment clearly goes beyond this.
The group has taken advantage of how simple it is today to produce relatively slick digital output. It has then had success in disseminating this propaganda far and wide online, relying on social media channels commonly used by young people. Part of this propaganda has attempted to demonstrate that the Islamic State’s supporters are never too young to join the fight. For example, in March 2015, the Islamic State released a video of a child murdering an Israeli Arab accused of being a spy.42 Such an act is intended to serve as an inspiration to other young supporters.
Conventional teenage concerns such as peer pressure and wanting to impress one’s contemporaries have been mobilized by the Islamic State as recruiting tools. For example, one Islamic State recruiter has used the example of girls taking up the call to violence in order to shame their male counterparts. Following the arrest of alleged Paris train station plotter Madani, Kassim castigated the Islamic State’s male supporters via Telegram. “The women, our sisters, went into action … where are the men? … you have to understand that if these women went into action, it’s because so few men are doing anything … why are you waiting so long to the point the woman are overtaking you in terms of honor?”43 Two 15-year-old boys in contact with Kassim were subsequently arrested in the days that followed for planning separate knife attacks in France.44
Kassim’s frustrations notwithstanding, since al-Adnani’s September 2014 call to arms, the Islamic State has had significant success in persuading teenagers in the West to carry out attacks. Unfortunately, the data suggests that the problem of teenage radicalization is worsening.
There are several possible reasons for this. One may be the tempo of Kassim’s activities. As he is believed to have been killed in a U.S. strike near Mosul earlier this month,45 perhaps the number of teenage plotters will subsequently diminish. Another is the situation on the ground. Local and regional counterterrorism measures have made traveling to Syria more challenging. Moreover, the Islamic State is no longer capturing territory at a rapid rate; indeed, it is being forced to relinquish parts of its caliphate. As a result, the group has put greater emphasis on its adherents attacking at home rather than traveling to Syria. Indeed, in May 2016, al-Adnani explicitly stated “that the smallest act you do in their lands is more beloved to us than the biggest act done here; it is more effective for us and more harmful to them.”46 Kassim made the same point.47
The threat posed by radicalized teens and pre-teens—of both sexes—has increased since the Islamic State declared its caliphate. This reality has already led to two deaths and over two dozen injuries in the West and makes a persuasive case for a greater counterterrorism focus on Islamic State operatives inciting and directing precisely this kind of attack. CTC
Robin Simcox specializes in counterterrorism and national security research as the Margaret Thatcher Fellow at the Heritage Foundation. Follow @RobinSimcox
Appendix: Terrorist Plots and Attacks by Teens and Pre-Teens in West since Islamic State’s Call for Attacks
September (Melbourne, Australia)
Abdul Numan Haider, 18, attacks police.
October (Vienna, Austria)
“Mertkan G.,” 14, plot targets civilians.
December (Sydney, Australia)
Unnamed perpetrator, 14, targets police.
February (Raleigh, North Carolina, United States)
Unnamed perpetrator, 16, targets military.
April (Melbourne, Australia)
Sevdet Besim, 18, plots to target civilians and police; ‘B,’ 14, in Blackburn, United Kingdom, encourages this plot.
May (Melbourne, Australia)
Unnamed perpetrator, 17, unspecified target.
June (Morganton, North Carolina, United States)
Justin Sullivan, 19, plots to target civilians.
July (Port-Vendres, France)
“Ismael K.,” 17, and “Antoine F.,” 19, plots to target military.
October (Sydney, Australia)
Farhad Jabar, 15, and Raban Alou, 18, attack police.
November (Merced, California, United States)
Faisal Mohammad, 18, attacks civilians.
January (Marseille, France)
Unnamed perpetrator, 15, targets a civilian.
January (Copenhagen, Denmark)
Unnamed perpetrator, 16, targets civilians.
February (Hannover, Germany)
“Safia S.,” 15, targets police.
March (Paris, France)
Two unnamed perpetrators, 15 and 17, target civilians.
March (Berlin, Germany)
“Shaas al-M.,” 19, unspecified target.
April (Essen, Germany)
“Mohammed B.,” “Yusuf T.,” 16, and “Tolga I.,” 17, attack civilians.
May (Sydney, Australia)
Tamim Khaja, 18, targets civilians.
July (Tucson, Arizona, United States)
Mahin Khan, 18, targets civilians.
July (Würzburg, Germany)
Muhammad Riyad, 17, targets civilians.
July (Normandy, France)
Abdelmalik Petitjean, 19, and Adel Kermiche, 19, attack civilians.
August (Paris, France)
Unnamed perpetrator, 16, unspecified target.
August (Clermont Ferrand, France)
Unnamed perpetrator, 18, unspecified target.
September (London, United Kingdom)
Haroon Ali Syed, 19, targets civilians and military.
September (Paris, France)
Unnamed perpetrator, 15, unspecified target.
September (Paris, France)
Ines Madani, 19, targets civilians and police.
September (Sydney, Australia)
Unnamed perpetrator, 18, targets civilians.
September (Paris, France)
Unnamed perpetrator, 15, targets civilians.
September (Schleswig-Holstein, Germany)
“Mahir al-H.,” 17, and “Ibrahim M.,” 18, unspecified target.
September (Paris, France)
Unnamed perpetrator, 15, unspecified target.
September (Cologne, Germany)
“Mohamed J.,” 16, unspecified target.
September (Nice, France)
Unnamed perpetrators, 17 and 19, unspecified target.
October (Sydney, Australia)
Unnamed perpetrators, 16, unspecified target.
October (Columbus, Ohio, United States)
Abdul Razak Ali Artan, 18, attacks civilians.
November (Ludwigshafen, Germany)
Unnamed perpetrator, 12, targets civilians.
[a] Definitions of what constitutes “the West” vary. In this article, however, it includes North America, Europe, and Australia.
[b] For example, if an individual was in possession of propaganda identifiably belonging to the group or if they were known to be following the September 2014 instructions from Abu Mohammed al-Adnani.
[c] This classification was previously—and helpfully—used by Sam Mullins. See Sam Mullins, “The Road to Orlando: Jihadist-Inspired Violence in the West, 2012-2016,” CTC Sentinel 9:6 (2016): p. 26.
[d] Kassim was allegedly in contact with Abdelmalik Petitjean and Adel Kermiche, who murdered Catholic priest Jacques Hamel; a 16-year-old girl arrested in Melun, a Paris suburb; an 18-year-old girl arrested in Clermont Ferrand, France; Ines Madani, whose plans included bombing a train station; two 15-year-old boys arrested in Paris who were planning knife attacks; a French Egyptian, also aged 15, who volunteered to carry out a terrorist operation; and two girls, aged 17 and 19, who lived in Nice and were also planning an attack. Lori Hinnant, “Officials: 1 IS recruiter links attackers, jihadis in France,” Associated Press, September 12, 2016; “Did jihadist Rashid Kassim lure French youths to plot attacks?” BBC News, September 15, 2016; “Police in France arrest teenagers in Nice on suspicion of terrorism,” DW, September 25, 2016.
[e] “Safia S.” had met Islamic State recruiters in Turkey. The 16-year-old girl who planned to bomb two schools in Copenhagen did so with an individual who had fought alongside the Islamic State in Syria. “From Hanover to IS: The case of Safia S.,” Deutsche Welle, October 19, 2016; “Danish teen charged with plot to bomb Jewish school,” Jewish Telegraphic Agency, March 8, 2016; “Danish 16-year old girl charged with planning to bomb schools,” Reuters, March 8, 2016; Jamie Crawford, “U.S. soldier helps foil plot to blow up school in Denmark,” CNN, April 21, 2016. “Shaas al-M” joined the Islamic State and fought alongside the group while in Syria before heading to Germany. Ruth Bender, “Germany Charges Syrian Immigrant With Supporting ISIS,” Wall Street Journal, October 27, 2016. “Mahir al-H” and “Ibrahim M” are suspected of being sent to Germany by the Islamic State in preparation for an attack. Andy Eckardt, “Germany Arrests 3 in Schleswig-Holstein Suspected of ISIS Links,” NBC News, September 13, 2016.
 Rita Panahi and Wes Hosking, ‘Islamic State death cult claims responsibility for Numan Haider’s knife attack on police’, Herald Sun, November 22, 2014.
 “Report: 12-year-old planned two bomb attacks in German city of Ludwigshafen,” Deutsche Welle, December 16, 2016.
 Ian Cobain, “The boy who didn’t stand out,” Guardian, July 14, 2005.
 Christophe Cornevin, “Près de 2000 mineurs radicalisés en France,” Le Figaro, September 22, 2016.
 “5 Stats On Millennials, Teens & Social Media,” YPulse, August 2, 2016.
 Thomas Joscelyn, “Terror plots in Germany, France were ‘remote-controlled’ by Islamic State operatives,” Long War Journal, September 24, 2016.
 “Mehr Mädchen unter radikalisierten Jugendlichen,” Zeit.de, September 10, 2016.
 For example, see Lori Hinnant, “European women who join Islamic State almost never leave,” Associated Press, May 28, 2015, and Harriet Sherwood, Sandra Laville, Kim Willsher Ben Knight, Maddy French, and Lauren Gambino, “Schoolgirl jihadis: the female Islamists leaving home to join Isis fighters,” Guardian, September 29, 2014.
 Robin Simcox, Hannah Stuart, Houriya Ahmed, and Douglas Murray, “Islamist Terrorism: The British Connections” (2nd Ed.), Henry Jackson Society, July 2011.
 Robin Simcox and Emily Dyer, “Al-Qaeda in the United States: A Complete Analysis of Terrorism Offenses,” Henry Jackson Society, February 2013.
 “Report: 12-year-old planned two bomb attacks in German city of Ludwigshafen.”
 Nick Hansen, “Sydney Opera House security incident: Teenager charged,” Daily Telegraph (Australia), September 9, 2016.
 “Gunman who shot dead NSW police employee was radicalised youth,” Australian Broadcasting Corporation, October 3, 2015.
 Adam Nossiter and Hannah Olivennes, “Jacques Hamel, 85, a Beloved French Priest, Killed in His Church,” New York Times, July 26, 2016.
 “Terror plots in Germany, France were ‘remote-controlled’ by Islamic State operatives.”
 Chris Pleasance, “French Muslim teenager arrested on terror charges ‘was told to “hit France” by ISIS recruiter after his mother reported him to authorities and blocked him going to Syria,” Daily Mail, July 17, 2015.
 Neelima Choahan, “Sevdet Besim, 19, gets 10 years’ jail for Anzac Day plot to behead police officer,” Age, September 5, 2016.
 Pete Williams, Jonathan Dienst, and Tracy Connor, “Ohio State Attacker Abdul Razak Ali Artan Bought Knife in Washington,” November 30, 2016.
 Henry Samuel, “Teenager who swore allegiance to Isil one of three women arrested for planning ‘imminent attack’ on Paris train station,” Telegraph, September 9, 2016.
 Will Worley, “Sikh Temple bombing in Germany was ‘carried out by Isis sympathisers,’” Independent, April 29, 2016.
 Janet Fife-Yeomans, Yoni Bashan, Lia Harris, Cathy Morris, and Taylor Auerbach, “Parramatta shooting: Multiple shots fired outside police HQ on Charles Street,” Daily Telegraph (Australia), October 3, 2015.
 For “loner” typology, see Raffaello Pantucci, “A Typology of Lone Wolves: Preliminary Analysis of Lone Islamist Terrorists,” International Centre for the Study of Radicalisation and Political Violence, March 2011.
 Wendy Halloran, “Documents: Arizona terror suspect indicated support for ISIS, Taliban,” 12 News, July 6, 2016.
 “Al-Furqan: The names linked to a shuttered Islamic Centre in Melbourne,” Australian Broadcasting Corporation, March 7, 2016.
 Simcox and Dyer, “Al-Qaeda in the United States: A Complete Analysis of Terrorism Offenses.” See also Daveed Garternstein-Ross and Nathaniel Barr, “The Myth of Lone-Wolf Terrorism,” Foreign Affairs, July 26, 2016.
 Jack Moore, “Abdel Malik Petitjean: What We Know About Second ISIS-Inspired Priest Attacker,” Newsweek, July 28, 2016.
 Alistair Jamieson and Nancy Ing, “France Church Attack: Abdel-Malik Petitjean Was Known Potential Radical,” NBC News, July 28, 2016.
 James Dowling and Anthony Dowlsey, “Inside the Anzac Day terror plot,” Herald Sun, July 11, 2016.
 “From Hanover to IS: The case of Safia S.”
 Jamieson and Ing.
 Jack Cloherty and Jack Date, “Father Tips Off Police to Son’s Alleged Islamic State Sympathies, Authorities Say,” ABC News, June 22, 2015.
 James McAuley, “Foiled Paris attack near Notre Dame deemed intelligence success by France,” Washington Post, September 9, 2016.
 Angelique Chrisafis, “Women arrested in Paris had planned ‘imminent’ attack on Gare de Lyon, say officials,” Guardian, September 9, 2016.
 “From Hanover to IS: The case of Safia S.;” Ruth Bender, “Trial of Teenager ‘Safia S’ Starts Behind Closed Doors in Germany,” Wall Street Journal.
 Robin Simcox and Emily Dyer, “The Role of Converts in Al-Qa`ida-Related Terrorism Offenses in the United States,” CTC Sentinel 6:3 (2013).
 Jens Hack, “German train ax attack puts Merkel migrant policy back in spotlight,” Reuters, July 19, 2016.
 “Germany: Syrian teen scouted attack sites for IS in Berlin,” Associated Press, October 27, 2016.
 “Syrian teenager arrested in Germany ‘was planning Isil bomb attack,’” Daily Telegraph, September 22, 2016.
 Euan McKirdy, Stephanie Halasz, and Jason Hanna, “Germany: 3 alleged Islamic State members arrested in Paris attacks probe,” CNN, September 13, 2016.
 “ISIS Video Purportedly Shows Execution of Israeli-Arab Hostage, Muhammed Musallam,” NBC News, March 10, 2015.
 Kim Willsher, “Terror attacks being foiled ‘every single day’ in France, prime minister says,” Los Angeles Times, September 12, 2016.
 “Did jihadist Rashid Kassim lure French youths to plot attacks?”
 Ryan Browne and Paul Cruickshank, “US coalition targets top ISIS figure in Iraq strike,” CNN, February 10, 2017.
 “Islamic State encouraged supporters in U.S., Europe to launch attacks,” Los Angeles Times, June 16, 2016.
 Stacy Meichtry and Sam Schechner, “How Islamic State Weaponized the Chat App to Direct Attacks on the West,” Wall Street Journal, October 20, 2016.