The article below was published in the Spring 2019 edition of Active Measures, IWP’s student journal.
In the wake of the Arab Spring, nearly one thousand German citizens traveled to Syria and Iraq to join Islamist terrorist groups. About a third of these are now back in the Federal Republic. Returning Foreign Terrorist Fighters (FTFs) present a tremendous challenge for the German authorities, as many of them are combat experienced, can radicalize others, and recruit them to conduct attacks. Officials have mainly aimed at speedy incarceration proceedings in order to avoid public pressure and contain the immediate security risk. This only postpones the threat because prison sentences are typically short and, therefore, do not represent a long-term solution. To prevent returning FTFs from conducting attacks in Germany and undermining the social fabric, the country should tailor its approach for each case and reassert the legitimacy and relevance of the state using the legal system. Germany must further strengthen its intelligence and surveillance capabilities, improve border controls, and enhance its deradicalization and reintegration programs. Finally, to avoid falling into a “counter-terrorism fatigue,” Germany must develop a National Counter-Terrorism Strategy to address all dimensions of the challenge of Islamist terrorism.
According to the International Centre for the Study of Radicalisation, by 2018, a total of 41,490 citizens from 80 countries became affiliated with the terrorist organization Islamic State (IS). As of July 2018, 7,366 (20%) of these Foreign Terrorist Fighters (FTFs) have returned to their countries or are currently in repatriation processes. Germany, for its part, has seen a total of 960 citizens leave for Syria and Iraq to join Islamist terrorist groups, about a third of whom (303) are now back in the Federal Republic. Returning FTFs present a serious problem for German law enforcement and national security officials because a significant number of them (at least 80) have experienced armed combat or, at a minimum, undergone some type of military training. Thomas Hegghammer has found that the presence of returning FTFs, who are more effective than “non-veterans,” increases the effectiveness of attacks in the West. While research shows that, historically, relatively few returning FTFs have posed a direct threat, those that did, were “responsible for some of the most lethal terrorist attacks carried out over the past three decades.” For example, the group of operatives that attacked Paris in November 2015, killing 129 people, was comprised of nine individuals, seven of whom were returning FTFs who had been sent to Europe by IS to conduct a large-scale attack. A lesser-acknowledged threat posed by returning FTFs is that they are also able to recruit others to conduct attacks locally. Germany faces the challenge of determining who these returnees are, what specific risk they pose, and, most importantly, what action to take to protect the public from potential harm.
Germany’s Approach So Far
It must be said that Germany has not yet found an adequate way to address the problem of returning FTFs. While progress has been made since 2016, especially by limiting the number of refugees arriving in the country, Germany has improved neither the centralization nor the structure of its security architecture significantly enough. Thus, authorities remain overwhelmed due to the high number of cases.
As in most other European countries, the German government unofficially prefers that foreign fighters would not return, without formally preventing them from returning. Generally, when FTFs return, they go to provisional detention to await trial. If convicted and put in prison, different detention regimes are applied, from isolation to dispersal among other detainees. But at a closer look, the situation is much more precarious. Thus far, the German government has failed to design and maintain a coherent approach to the multifaceted challenge that FTFs represent.
Most officials aim for speedy incarceration proceedings in order to avoid public pressure and contain the immediate security risk. On average, verdicts tend to impose sentences of “three to four years for the active support of the Islamic State rather than on more concrete charges of murder.” Critics of this approach have argued that this will likely only delay the threat for a relatively short period of time until detainees are released. Even more significantly, while the prosecuting authority does open a criminal investigation in every case of a returning FTF, evidence rules under German criminal law often mean that a returnee is not convicted of a criminal offense at all. Accordingly, most of the men and women who have returned from the war zones in Syria and Iraq, are at large. For instance, out of the 80 individuals who left Hamburg for IS, 25 have returned – but only one is in custody. In many cases, there is simply no evidence that the departed were, in fact, members of or supported a terrorist group.
In 2016, five terrorist attacks hit Germany, and seven more were foiled. This figure includes the first successful mass casualty attack on December 19, 2016, wherein Anis Amri, a Tunisian refugee, drove a truck into a popular Christmas market in Berlin, killing twelve and wounding nearly a hundred civilians. Amri had been known to the authorities for more than a year but was eventually categorized as a minor threat by the Federal Criminal Police (“Bundeskriminalamt,” BKA). For nearly two years since then, however, Germany has seen few attacks of comparable magnitude, one perhaps being the July 28, 2017 stabbing of civilians at a supermarket in Hamburg that killed one and injured seven. Furthermore, as of late 2017, the FTFs returning to Germany are not reported to have plotted another attack in Germany – in sharp contrast to those returning to France, who have executed dozens of attacks since 2014.
This relative decrease in attacks, coinciding with the collapse of IS in Iraq and Syria, could easily make for a “counter-terrorism fatigue” that, experts assert, is looming. As the focus shifts to other, seemingly more urgent, problems in society, there is a danger of assessing the threat of returning FTFs incorrectly and repeating the mistakes of the past. Whatever their reason for returning to Germany, all returnees “will continue to pose some degree of risk,” especially when considering the potential of their joining up with those individuals within Germany who hold extremist views but were prevented from joining IS or other jihadist organizations in person.
To address the challenge in all its dimensions, Germany must establish a coherent national counter-terrorism strategy that effectively incorporates successful practices of other nations, makes the best use of the German legal system, and, most importantly, counters the contributing factors that provide the breeding ground for terrorism in the first place (non-kinetic counterterrorism). As for the focus of this paper, the following assessment will identify the most crucial tasks to efficiently counter the threat of returning FTFs. The strategic objective must be to prevent returning FTFs from conducting attacks in Germany and undermining the social fabric. The following five lines of effort represent the means for achieving this objective:
- Tailor the Approach for Each Case
- Reassert the Legitimacy and Relevance of the German State Using the Legal System
- Strengthen Intelligence and Surveillance Capabilities
- Improve Border Controls
- Deradicalize and (Re)-Integrate
1. Tailor the Approach for Each Case
The issue of returning FTFs is demonstrably too multifaceted to use a “one-size-fits-all”-approach. Richard Barrett of The Soufan Group has shown that broadly, returnees fall into five categories, each presenting a different level of risk:
“(i) those who left early or after only a short stay and were never particularly integrated with IS;
(ii) those who stayed longer, but did not agree with everything that IS was doing;
(iii) those who had no qualms about their role or IS tactics and strategy, but decided to move on;
(iv) those who were fully committed to IS but forced out by circumstances, such as the loss of territory, or were captured and sent to their home countries; and
(v) those who were sent abroad by IS to fight for the caliphate elsewhere.”
But even this categorization has flaws. As Rukmini Callimachi of The New York Times revealed in an interview with a returnee who is now in prison in Bremen, IS was aware that authorities are more likely to be lenient with those returnees who came back after only a short stay: “When they go back to France or Germany, they can say, ‘I was only on holidays in Turkey,’ […] The longer they stay in the Islamic State, the more suspicious the secret service in the West gets, and that’s why they try to do the training as quickly as possible.” Accordingly, a short stay does not necessarily equal innocence. It is especially worrisome that merely 10%, according to data collected on the motivation for returning to Germany, returned because they actually wished to abandon the Islamic State. Most FTFs returned because they grew disillusioned and frustrated with their situation, followed calls by family and friends, or for health or logistical reasons, such as “to procure supplies, raise funds or rest.”
Additionally, there are age and gender distinctions to be made. Prosecutors, prior to a change in policy in December 2017, were hesitant to open criminal investigations against women, for instance. And while some women may, indeed, have been coerced by their husbands into traveling to Syria, most will have gone there willingly, and “must be assumed to have known what they were doing.” Another question is how to deal with minors. In Germany, the age of criminal liability is 14, but, since six-year-olds will have been exposed to jihadi indoctrination and nine-year-olds will have received military training (the “Cubs” of IS), not even children can safely be assumed to not represent any threat. Therefore, Germany must look at each case individually and apply the correct measures. In some cases, it may be possible to completely re-integrate women, teenagers, and even men; in others, it may not, which is when incarceration is the (immediate) answer. This approach also avoids basing the severity of state repression solely on the duration of the time spent abroad. Where it applies, the Federal Republic must not be afraid to take strong action against terrorists, with all confident authority of the rule of law. In short, the German response to returnees needs to be “both multifaceted and specific,” a tailored approach to each sub-group and individual.
2. Reassert the Legitimacy and Relevance of the German State Using the Legal System
Some counterterrorism specialists, like David Wells, have argued that because it is so difficult to adequately deal with returning FTFs, European countries should repatriate foreign fighters who have been prevented from returning home by fear of a long prison sentence. Returnees would be expected “to plead guilty to one or a range of terrorism offences in exchange for a reduced prison sentence.” While others, such as Phil Gurski, have pointed out that this would likely cause a backlash in public reaction, there are even more relevant arguments that speak against this type of “amnesty” arrangement. First of all, it is highly unlikely that radicalized returnees would even agree to strike a deal with a legal system they fundamentally reject. Secondly, it would be nearly impossible for Germany to logistically ensure the repatriation of individuals from conflict zones, and thirdly, settling for shorter sentences during plea-bargaining procedures is in direct contradiction with the increased criminalization of terrorism-related offences, as United Nations Security Council Resolution (UNSCR) 2178 has called for. Most importantly, however, the German legal system includes certain mechanisms that prevent methods like plea agreements altogether. Germany has no “common law,” which means that defendants instead confess to charges made against them.
Another approach that will not work in Germany is to hold “in absentia” trials. In cases in the Netherlands and Belgium, authorities have begun trials in absence of the defendant to send a strong message: “These people think they have said farewell to our legal system, but we have not said farewell to them.” According to German law, however, prosecutions in absentia are not permitted because of the “immediacy principle,” which requires individuals to be present in court. In light of this reality, some German politicians have argued for the revocation of citizenship of those who left to join IS, and the issue has been debated publicly. Here again, however, the law complicates things: Article 16 of the German “Grundgesetz” (Basic Law or Constitution) does not allow for the deprivation of citizenship of German FTFs.
Given these circumstances, Germany must find other ways to adequately address the challenge of returning FTFs. UNSCR 2178, a legally binding document, prescribes that Germany is obligated to prosecute and convict not just travelers themselves, but also the recruiters and facilitators. Additionally, refusing to hand down harsh sentences (as in the suggested amnesty arrangement), even though the evidence would permit it, has the opposite effect of deterring potential future fighters. Legal authorities should consider leniency only in rare cases.
To be able to have a tailored approach for each case, Germany must gain better access to intelligence that could lead to more evidence-based convictions. Therefore, the state should consider incentivizing individuals to come forward with relevant information. There are few returnees who serve as credible witnesses in court, and the handful that do, have generally not benefited from their testimonies. An example is a returnee from Bavaria who assisted the authorities but still received a prison sentence of eleven years. German Islamic scholar and terrorism expert Guido Steinberg, while understanding the judge’s motivation, believes the verdict sent the wrong signal to the Islamist community: Cooperation will not be rewarded.
In either case, it is crucial that Germany reassert the legitimacy and relevance of the state. In this regard, it is not necessarily a bad thing that Germany cannot revoke the citizenship of its returning FTFs. By taking ownership of even its “worst” citizens, the Federal Republic can demonstrate its own validity and discredit that of the so-called Islamic State. While not incentivizing dangerous actors to return home via short prison sentences that only postpone the problem, authorities should justly punish those returnees who defy the liberal democratic order, yet also work with those individuals who are sincerely remorseful and assist the state by providing valuable information. Returnees must be made aware that the state will use its legitimate powers to constrain those who aim to undermine it.
3. Strengthen Intelligence and Surveillance Capabilities
As the legal dimension has shown, it is difficult to consistently convict and incarcerate returnees due to the lack of clear evidence of crimes committed. Therefore, it is of the utmost importance that the German intelligence apparatus strengthen its capabilities and effectively monitor those persons posing a potential threat to public safety. It is unacceptable that many returnees who were not imprisoned have simply disappeared from view.
To this end, it is vital to develop a system in which intelligence is shared effectively. In 2004, Germany established a fusion center for jihadi terrorism, the “Joint Counter-Terrorism Center” (GTAZ, “Gemeinsames Terrorabwehrzentrum”) in Berlin, to coordinate efforts and provide a platform for intelligence sharing. Nevertheless, there is no central authority, as the “Länder” (states) each have the prerogative to develop their own solutions. Steinberg has made the case that the country’s intelligence services need “a complete overhaul,” and that the police and intelligence offices of the individual states should be put under the control of the respective federal institutions. The current arrangement epitomizes the lack of a holistic strategy, and the government itself has articulated the need to better coordinate the efforts of the federal, state, and local governments.
In the same way, international cooperation must be strengthened. The Schengen system, through which border checkpoints have mostly been eliminated, makes it easy for travelers to move from one European country to the next. This fact contributes to the need for an effective European intelligence sharing system. Long-term international cooperation is crucial and in line with UNSCR 2396 (2017), which calls on Member States to “improve the collection and sharing of information and evidence,” as well as a 2017 European Parliament directive.
4. Improve Border Controls
To ensure that no returning FTFs can enter the country undetected, Germany has to re-establish control over its borders. Essentially, the Schengen borders must function “like national border controls of better-organized European states.” Accordingly, all 26 signatories (including non-EU members) and their security authorities must have access to the data coming from the state of initial entry.
Additionally, the refugee problem calls for a “soberer approach.” It has been a good step to limit the number of people coming in since 2015, a year in which Germany allowed over a million of refugees to enter the country, initially without even vetting them. It is absolutely necessary to submit newcomers to strenuous vetting processes,国产偷拍视频 to prevent harm to society at the first point of contact and not overwhelm authorities. To this end, the European Border and Coast Guard Agency (known as “Frontex”) must be given more resources and public support.
5. Deradicalize and (Re-)Integrate
Even those FTFs that are imprisoned upon their return to Germany will eventually have to be released, as prison sentences so far have rarely been longer than 10 years. In light of this reality, it is paramount that Germany begin the re-integration process as soon as possible. The more correct term in this regard is “integration,” because most returnees were never integrated to society in the first place, as their choice to join IS clearly demonstrates. Integration efforts must begin in prison, especially to prevent returnees from recruiting other inmates, like prior to the attack on Paris in 2015. Authorities should also consider making participation in integration and de-radicalization programs, as well as a public renunciation of IS and its radical ideology, a requirement before release, and continue this process once individuals are free again.
Most importantly, any new or revamped integration programs must be built upon the fundamental understanding that if one wants to combat terrorism at its roots, one has to deal with the societal issues that allow jihadists to gain access to hearts and minds. As David Ucko and Thomas Marks have so eloquently put it, “the government should concern itself intimately with the drivers of alienation and the roots of its own illegitimacy.” The fact that those German Muslims who left for IS were open to an ideology that required them to radically turn against their own society, demonstrates that they did not consider themselves part of it. Ultimately, then, integration is about creating the feeling of belonging to the community. In this regard, it was a welcome sign that Germany established a National Strategy on the Prevention of Extremism in July 2016, pledging to increase funding for integration and prevention programs.
Germany has made steps in the right direction in countering the threat that returning FTFs represent to the national security. Nevertheless, much work remains to be done. If the country implements the aforementioned lines of effort, it will be much more likely to achieve the strategic objective of preventing FTFs from conducting attacks in the country and undermining the nation’s social fabric. As a matter of course in addition to the National Strategy on the Prevention of Extremism, Germany must develop a holistic National Counter-Terrorism Strategy that includes a comprehensive approach to countering totalitarian Islamist ideology. This includes integrating the various agencies and means available to the German government. Only if this is done can the country hope to successfully deal with all the dimensions of the threat, which include returning FTFs, homegrown terrorists, and other potentially violent extremists. Germany must avoid falling into a “counter-terrorism fatigue” – now is the time to develop and adopt policies that are needed to deal with the current threat and prevent new generations from mobilizing, if and when a new opportunity for mobilization arises.
 Joana Cook and Gina Vale, “From Daesh to ‘Diaspora’: Tracing the Women and Minors of Islamic State,” International Centre for the Study of Radicalisation国产偷拍视频, July 23, 2018: 3, accessed November 5, 2018, http://icsr.info/wp-content/uploads/2018/07/ICSR-Report-From-Daesh-to-%E2%80%98Diaspora%E2%80%99-Tracing-the-Women-and-Minors-of-Islamic-State.pdf.
 Joana Cook, “From Daesh to ‘Diaspora,’” 3.
国产偷拍视频 Ibid., 16, 17.
 Daniel Heinke, “German Foreign Fighters in Syria and Iraq: The Updated Data and Its Implications,” CTC Sentinel 10, no. 3 (March 2017): 17, accessed November 4, 2018, http://ctc.usma.edu/app/uploads/2017/03/CTC-Sentinel_Vol10Iss330.pdf; Thomas Renard and Rik Coolsaet (ed.), “Returnees: Who Are They, Why Are They (Not) Coming Back and How Should We Deal with Them? Assessing Policies on Returning Foreign Terrorist Fighters in Belgium, Germany and the Netherlands,” Egmont – The Royal Institute for International Relations国产偷拍视频 Publications, February 6, 2018: 44, accessed November 7, 2018, http://www.egmontinstitute.be/content/uploads/2018/02/egmont.papers.101_online_v1-3.pdf?type=pdf.
 Thomas Hegghammer, “Should I Stay or Should I Go? Explaining Variation in Western Jihadists’ Choice between Domestic and Foreign Fighting,” American Political Science Review 107, no.1 (February 2013): 11, accessed November 6, 2018, http://hegghammer.com/_files/Hegghammer_-_Should_I_stay_or_should_I_go.pdf.
 “The Challenge of Returning and Relocating Foreign Terrorist Fighters: Research Perspectives,” United Nations Security Council, Counter-Terrorism Committee Executive Directorate (CTED) Trends Report, April 11, 2018: 3, accessed October 31, 2018, http://www.un.org/sc/ctc/wp-content/uploads/2018/04/CTED-Trends-Report-March-2018.pdf.
 Kim Cragin, “The November 2015 Paris Attacks: The Impact of Foreign Fighter Returnees,” Orbis国产偷拍视频 61, no. 2, (Spring 2017): 218, accessed November 1, 2018, http://www.fpri.org/article/2017/03/november-2015-paris-attacks-impact-foreign-fighter-returnees/.
国产偷拍视频 Cragin, “2015 Paris Attacks,” 221.
 “Challenge of Returning,” United Nations, 11.
 Guido Steinberg, “Islamist Terrorism in Germany: Threats, Responses, and the Need for a Strategy,” American Institute for Contemporary German Studies国产偷拍视频 Policy Report 66, December 20, 2017: 18, accessed November 1, 2018, http://www.aicgs.org/site/wp-content/uploads/2017/12/PR-66-DAAD-Steinberg-Terrorism.pdf.
 Thomas Renard, “Returnees: Who Are They,” 4.
 Eva Entenmann, “Why ‘Amnesty’ Should Not Be Considered for Returning Foreign Fighters: A Response to Wells and Gurski,” International Centre for Counter-Terrorism – The Hague Publications, January 20, 2017, accessed November 6, 2018, http://icct.nl/publication/why-amnesty-should-not-be-considered-for-returning-foreign-fighters-a-response-to-wells-and-gurski/.
 Daniel Heinke, “German Foreign Fighters,” 20.
 Thomas Renard, “Returnees: Who Are They,” 50.
 Martin Knobbe, “Die meisten Rückkehrer sind auf freiem Fuß“ (“Most Returnees Are at Large”), Der Spiegel国产偷拍视频, January 12, 2018, accessed November 1, 2018, http://www.spiegel.de/politik/deutschland/islamischer-staat-die-meisten-syrien-rueckkehrer-sind-auf-freiem-fuss-a-1187460.html.
国产偷拍视频 Martin Knobbe, “Most Returnees at Large.”
国产偷拍视频 Guido Steinberg, “Islamist Terrorism in Germany,” 7.
 Ibid., 17.
 “GTD ID: 201707280023 – Incident Summary,” National Consortium for the Study of Terrorism and Responses to Terrorism (START), 2018, Global Terrorism Database, accessed November 13, 2018, http://www.start.umd.edu/gtd/search/IncidentSummary.aspx?gtdid=201707280023.
 Guido Steinberg, “Islamist Terrorism in Germany,” 15.
 Thomas Renard, “Returnees: Who Are They,” 76.
 Richard Barrett, “Beyond the Caliphate: Foreign Fighters and the Threat of Returnees,” The Soufan Group, October 31, 2017: 5, accessed October 31, 2018, http://thesoufancenter.org/wp-content/uploads/2017/11/Beyond-the-Caliphate-Foreign-Fighters-and-the-Threat-of-Returnees-TSC-Report-October-2017-v3.pdf.
 Joana Cook, “From Daesh to ‘Diaspora,’” 61.
 Richard Barrett, “Beyond the Caliphate,” 18.
 Rukmini Callimachi, “How a Secretive Branch of ISIS Built a Global Network of Killers,” The New York Times, August 3, 2016, accessed November 1, 2018, http://www.nytimes.com/2016/08/04/world/middleeast/isis-german-recruit-interview.html.
国产偷拍视频 Thomas Renard, “Returnees: Who Are They,” 44.
 Ibid., 50.
国产偷拍视频 Ibid., 23.
 “The Return of Foreign Fighters to EU Soil,” European Parliament Research Service Study, May 5, 2018: 51, accessed November 5, 2018, http://www.europarl.europa.eu/RegData/etudes/STUD/2018/621811/EPRS_STU(2018)621811_EN.pdf.
 Thomas Renard, “Returnees: Who Are They,” 74. See also, for instance, Mia Bloom, John Horgan, Charlie Winter, “Depictions of Children and Youth in the Islamic State’s Martyrdom Propaganda, 2015-2016,” CTC Sentinel国产偷拍视频 9, no. 2 (February 2016): 29-32, accessed November 20, 2018, http://ctc.usma.edu/app/uploads/2016/02/CTC-SENTINEL-Vol9Iss214.pdf.
国产偷拍视频 Peter Neumann, “Eine bundesweite Präventionsstrategie gegen den gewaltbereiten Islamismus: Öffentliche Anhörung, Innenausschuss des Deutschen Bundestages“ (“A Nationwide Preventive Strategy against Violent Islamism: Public Hearing, Interior Committee of the German Federal Parliament“), June 26, 2017, accessed November 1, 2018, http://www.bundestag.de/blob/512960/9128d2155a7f760d450621003906d96b/18-4-922-f-data.pdf.
 Daniel Heinke, “German Foreign Fighters,” 17.
 David Wells, “Could Repatriating Foreign Fighters Make Europe Safer?” International Centre for Counter-Terrorism – The Hague国产偷拍视频 Publications, November 25, 2016, accessed November 1, 2018, http://icct.nl/publication/could-repatriating-foreign-fighters-make-europe-safer/.
 Phil Gurski, “Should Governments Offer Amnesty to Returning Foreign Fighters?” International Centre for Counter-Terrorism – The Hague Publications, November 4, 2016, accessed November 6, 2018, http://icct.nl/publication/should-governments-offer-amnesty-to-returning-foreign-fighters/.
国产偷拍视频 Eva Entenmann, “Why ‘Amnesty’ Should Not Be Considered.”
 Christophe Paulussen and Kate Pitcher, “Prosecuting (Potential) Foreign Fighters: Legislative and Practical Challenges,” International Centre for Counter-Terrorism – The Hague Research Paper, January 30, 2018: 21, accessed November 6, 2018, http://icct.nl/wp-content/uploads/2018/01/ICCT-Paulussen-Pitcher-Prosecuting-Potential-Foreign-Fighters-Legislative-Practical-Challenges-Jan2018.pdf.
 Christophe Paulussen, “Prosecuting (Potential) Foreign Fighters,” 23.
 “The Return of Foreign Fighters,” European Parliament, 44.
 Ibid., 41.
 Christophe Paulussen, “Prosecuting (Potential) Foreign Fighters,” 15.
 Martin Knobbe, “Most Returnees at Large.”
 Richard Barrett, “Beyond the Caliphate,” 5.
国产偷拍视频 Thomas Renard, “Returnees: Who Are They,” 51.
国产偷拍视频 Ibid., 53.
国产偷拍视频 Guido Steinberg, “Islamist Terrorism in Germany,” 7.
 Ibid., 26.
 “Bundesregierung Beschließt Strategie zur Extremismusprävention“ (“Federal Government Enacts Strategy on the Prevention of Extremism”), Federal Ministry of the Interior, Building and Community, 国产偷拍视频Press Release, July 13, 2016, accessed November 5, 2018, http://www.bmi.bund.de/SharedDocs/kurzmeldungen/DE/2016/07/praeventionsstrategie-gegen-extremismus-mit-bmfsfj.html.
 “Challenge of Returning,” United Nations, 3.
 “The Return of Foreign Fighters,” European Parliament, 6.
 Guido Steinberg, “Islamist Terrorism in Germany,” 7.
 Ibid., 26.
 Ibid., 7.
 Georg Blume, “The Night Germany Lost Control,” ZEIT Online, August 30, 2016, accessed November 16, 2017, http://www.zeit.de/gesellschaft/2016-08/refugees-open-border-policy-september-2015-angela-merkel.
 Guido Steinberg, “Islamist Terrorism in Germany,” 7.
 Richard Barrett, “Beyond the Caliphate,” 27.
 Nasser Weddady, “Why Westerners Who Joined Islamic State Don’t Deserve an Automatic Death Sentence,” The Washington Post, 国产偷拍视频October 26, 2017, accessed November 1, 2018, http://www.washingtonpost.com/news/democracy-post/wp/2017/10/26/why-westerners-who-joined-islamic-state-dont-deserve-an-automatic-death-sentence/?utm_term=.4941e3b7e8f8.
 David Wells, “Repatriating Foreign Fighters.”
 Peter Neumann, “Eine bundesweite Präventionsstrategie.“
 David Ucko and Thomas Marks, “Violence in Context: Mapping the Strategies and Operational Art of Irregular Warfare,” Contemporary Security Policy 39, no. 2 (February 2018): 224, accessed October 28, 2018, http://www.tandfonline.com/doi/full/10.1080/13523260.2018.1432922.
国产偷拍视频 Peter Neumann, “Eine bundesweite Präventionsstrategie.“
 “Strategie der Bundesregierung zur Extremismusprävention und Demokratieförderung“ (“Strategy of the Federal Government to Prevent Extremism and Promoting Democracy“), The Government of the Federal Republic of Germany, July 13, 2016, accessed November 1, 2018, http://www.bmi.bund.de/SharedDocs/downloads/DE/veroeffentlichungen/2016/strategie-extremismuspraevention-und-demokratiefoerderung.html;jsessionid=EF7901BAFB7ABEAA99356B492FD6CF85.2_cid295.
 Thomas Renard, “Returnees: Who Are They,” 76.