1 Richard Barrett, “Foreign Fighters in Syria”, Soufan Group, June 2014, available at: www.jstor.org/stable/resrep10783, p. 9 (all internet references were accessed in August 2021).

2 Soufan Group, “Foreign Fighters: An Updated Assessment of the Flow of Foreign Fighters into Syria and Iraq”, Report, December 2015, available at: http://www.jstor.org/stable/resrep10784.3, p. 5.

3 Ibid., p. 5. See also Thomas Renard and Rik Coolsaet (eds), “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 Royal Institute for International Relations, 2018, available at: https://www.egmontinstitute.be/content/uploads/2018/02/egmont.papers.101_online_v1-3.pdf?type=pdf, p. 3.

4 Amandine Scherrer, “The Return of Foreign Fighters to EU Soil: Ex Post Evaluation”, European Parliamentary Research Service Study, available at: www.europarl.europa.eu/RegData/etudes/STUD/2018/621811/EPRS_STU(2018)621811_EN.pdf, Part I, p. 5.

5 Trudy Govier and David Boutland, “Dilemmas Regarding Returning ISIS Fighters”, Ethics & Global Politics, Vol. 13, No. 2, 2020, p. 93.

6 “ISIS Foreign Fighters After the Fall of the Caliphate”, Armed Conflict Survey, Vol. 6, 2020, p. 26.

7 There are indications that some of these FFs have managed to escape and are making their way back home. See, for example, Frank Gardner, “IS Prisoner Issue a Ticking Timebomb for the West”, BBC News, available at: https://www.bbc.com/news/world-middle-east-53428928 . It is the opinion of the present author that a controlled return would be better in terms of national security, especially in the longer term. On this point, see also Tanya Mehra and Christophe Paulussen, “The Repatriation of Foreign Fighters and Their Families: Options, Obligations, Morality and Long-term Thinking”, ICCT Perspective, 6 March 2019, available at: https://icct.nl/publication/the-repatriation-of-foreign-fighters-and-their-families-options-obligations-morality-and-long-term-thinking/; and “ISIS Foreign Fighters After the Fall of the Caliphate”, above note 6, p. 23.

8 The situation is slightly different for the FFs held in prison in Iraq given that some of them are actually being prosecuted in Iraq for the acts that they have committed during their time with IS, albeit not without issues. See, for example, Margaret Coker and Falih Hassan, “A 10-Minute Trial, a Death Sentence: Iraqi Justice for ISIS Suspects”, The New York Times, 17 April 2018, available at: https://www.nytimes.com/2018/04/17/world/middleeast/iraq-isis-trials.html.

9 On this point see also, for example, T. Mehra and C. Paulussen, above note 7.

10 Sandra Krähenmann, “Foreign Fighters under International Law”, Geneva Academy of International Humanitarian Law and Human Rights, Academy Briefing No. 7, 2014, p. 6.

11 Nils Melzer, Interpretative Guidance on the Notion of Direct Participation in Hostilities Under International Humanitarian Law, May 2009, available at: https://www.icrc.org/en/doc/assets/files/other/icrc-002-0990.pdf, p. 35. For a more in-depth assessment of the question of membership determination see, for example, Vanlandingham, R. E., “Meaningful Membership: Making War a Bit More Criminal”, Cardozo Law Review, vol. 35, no. 1, 2013, pp. 120–128Google Scholar.

12 See, for example, respectively, UN Security Council (UNSC) Resolution 2178 of 24 September 2014, adopted 24 September 2014; and “Directive (EU) 2017/541 of the European Parliament and of the Council of 15 March 2017 on Combating Terrorism and Replacing Council Framework Decision 2002/475/JHA and Amending Council Decision 2005/671/JHA”, Official Journal of the European Union, L 88/6, 31 March 2017.

13 Sandra Krähenmann, “The Interplay Between International Humanitarian Law, Terrorism and the ‘Foreign Terrorist Fighter’ Regime”, Proceedings of the ASIL Annual Meeting, Vol. 112, 2018, p. 309.

14 Bibi van Ginkel and Eva Entenmann (eds), “The Foreign Fighters Phenomenon in the European Union: Profiles, Threats & Policies”, ICCT Research Paper, April 2016, available at: https://icct.nl/app/uploads/2016/03/ICCT-Report_Foreign-Fighters-Phenomenon-in-the-EU_1-April-2016_including-AnnexesLinks.pdf, p. 13.

15 ICRC, “International Humanitarian Law and the Challenges of Contemporary Armed Conflict”, Report prepared for the 32nd International Conference of the Red Cross and Red Crescent, Geneva, 8–10 December 2015, p. 17 (hereafter ICRC Challenges Report 2015).

16 On this point, see Eurojust/the Genocide Network, “Cumulative Prosecution of Foreign Terrorist Fighters for Core International Crimes and Terrorism-Related Offences”, May 2020, p. 5 (hereafter Eurojust Genocide Network Report on Cumulative Prosecution), available at: https://www.eurojust.europa.eu/cumulative-prosecution-foreign-terrorist-fighters-core-international-crimes-and-terrorism-related, p. 7.

17 This paper builds further upon Hanne Cuyckens and Christophe Paulussen, “The Prosecution of Foreign Fighters in Western Europe: The Difficult Relationship Between Counter-Terrorism and International Humanitarian Law,” Journal of Conflict and Security Law, Vol. 24, 2019, pp. 537–565.

18 Ben Saul, “Terrorism and International Humanitarian Law”, in Ben Saul (ed.), Research Handbook on International Law and Terrorism, Edward Elgar, Cheltenham, 2020, p. 209.

19 McKeever, David, “International Humanitarian Law and Counter-Terrorism: Fundamental Values, Conflicting Obligations”, International & Comparative Law Quarterly, vol. 69, no. 1, 2020, p. 48CrossRefGoogle Scholar.

20 D. McKeever, above note 19, p. 44. See also Gasser, Hans-Peter, “Acts of Terror, ‘Terrorism’ and International Humanitarian Law”, International Review of the Red Cross, vol. 84, no. 847, 2002, p. 550Google Scholar; and O'Donnell, Daniel, “International Treaties Against Terrorism and the Use of Terrorism During Armed Conflict and by Armed Forces”, International Review of the Red Cross, vol. 88, no. 864, 2006, pp. 853–854CrossRefGoogle Scholar.

21 D. McKeever, above note 19, p. 43. On this point, see also, more particularly, Hmoud, Mahmoud, “Negotiating the Draft Comprehensive Convention on International Terrorism: Major Bones of Contention”, Journal of International Criminal Justice, vol. 4, no. 5, 2006, p. 1043CrossRefGoogle Scholar.

22 Macmillan, Moira, “The UN Foreign (Terrorist) Fighter Regime and International Criminal Law”, American Society of International Law Proceedings, vol. 112, 2018, p. 311Google Scholar. See also Sandra Krähenmann, “Legal Framework Addressing Terrorism and Counter-Terrorism”, Proceedings of the Bruges Colloquium, 20–21 October 2016, Collegium, No. 47, Autumn 2017, p. 19; and H.-P. Gasser, above note 20, p. 552.

23 M. Macmillan, above note 22, p. 312.

24 Alejandro Sánchez Frías, “Bringing Terrorists to Justice in the Context of Armed Conflict: Interaction Between International Humanitarian Law and the UN Conventions Against Terrorism”, Israel Law Review, Vol. 53, No. 1, 2020, p. 80.

25 D. McKeever, above note 19, p. 46. For an assessment of the risks and benefits of UNSC resolutions imposing international legal obligations on UN Member States with respect to Foreign (Terrorist) Fighters see DeBartolo, D., “Security Council ‘legislation’ on Foreign (Terrorist) Fighters”, American Society of International Law Proceedings, vol. 112, 2018, pp. 303–306Google Scholar.

26 S. Krähenmann, above note 13, p. 307.

27 Ibid.

28 T. Ferraro, “Interaction and Overlap Between Counter-Terrorism Legislation and International Humanitarian Law in Terrorism”, Proceedings of the Bruges Colloquium, 20–21 October 2016, p. 28.

29 Ibid., p. 30.

30 EU directive 2017/541, above note 12, preambular clause 37.

31 On this point, see, more particularly, the article by Thomas Van Poecke, Frank Verbruggen and Ward Yperman, “Terrorist Offences and the International Humanitarian Law Exclusion Clause: Belgium as the Odd One Out” in the same issue of the International Review of the Red Cross.

32 Contrast Prosecutor v. Imane B. et al. (District Court of The Hague, 10 December 2015), §§ 7.37–7.44 with Rechtbank van eerste aanleg (Antwerpen), Vonnis, 11 February 2015, p. 31 (Sharia4Belgium case) and Hof van Beroep (Brussels), Beslissing van de Kamer van Inbeschuldigingstelling, 14 September 2017 (PKK indictment). For a further discussion of the question whether the exclusion clause refers exclusively to State armed forces or not, see also Zwanenburg, Marten, “Foreign Terrorist Fighters in Syria: Challenges of the ‘Sending’ State”, International Law Studies, vol. 92, no. 1, 2016, pp. 226–227Google Scholar.

33 Prosecutor v. Imane B. et al., above note 32, paras 7.38 and 7.40.

34 Ibid., para. 7.39.

35 Sharia4Belgium case and PKK indictment, above note 32. See also O. Venet, “Infractions terroristes et droit humanitaire: l'article 141bis du Code pénal”, Journal des tribunaux, No. 6387, March 2010, p. 169; V. Koutroulis, “Le jugement du Tribunal correctionnel d'Anvers dans l'affaire dite « Sharia4Belgium » et l'article 141bis du Code pénal belge”, in A. Jacobs and D. Flore (eds), Les Combattants étrangers en Syrie, L'Harmattan, Paris, 2005, p. 88; T. Ruys and S. Van Severen, “Art. 141bis Sw. – Vervolging tussen hamer en aambeeld van terreurbestrijding in internationaal humanitair recht”, Rechtskundig Weekblad, 2018–19, no. 14, p. 531; and J. Wouters and T. Van Poucke, “Van strijdkrachten, terroristen en het Belgisch strafrecht (noot onder Brussel, 14 september 2017)”, Rechtskundig Weekblad, 2018–19, No. 14, p. 1617.

36 Apart from Belgium, the only other EU Member State that seems to have also integrated such a clause in its national legislation is the Republic of Ireland; see T. Van Poecke, “The IHL Exclusion Clause, and why Belgian Courts Refuse to Convict PKK Members for Terrorist Offences”, EJIL: Talk!, 20 March 2019, available at: https://www.ejiltalk.org/author/thomasvanpoecke/.

37 M. Macmillan, above note 22, p. 311. See also S. Krähenmann, above note 22, p. 19; and Geneuss, Julia, “The Legal Limbo of Counter-Terrorism Criminal Law and Armed Conflict. Anti-Regime and Anti-IS (Foreign) Fighters Before European Courts”, European Criminal Law Review, vol. 10, 2020, p. 342CrossRefGoogle Scholar.

38 B. van Ginkel, “The New Security Council Resolution 2178 on Foreign Terrorist Fighters: A Missed Opportunity for a Holistic Approach”, ICCT Perspectives, 4 November 2014, available at: https://icct.nl/publication/the-new-security-council-resolution-2178-on-foreign-terrorist-fighters-a-missed-opportunity-for-a-holistic-approach/.

39 A. De Guttry, “The Role Played by the UN in Countering the Phenomenon of Foreign Terrorist Fighters”, in A. de Guttry, F. Capone and C. Paulussen (eds), Foreign Fighters in International Law and Beyond, T.M.C. Asser Press, The Hague, 2016, p. 266.

40 Christophe Paulussen, “Impunity for International Terrorists? Key Legal Questions and Practical Considerations”, ICCT Research Paper, April 2012, p. 12, available at: https://www.icct.nl/app/uploads/download/file/ICCT-Paulussen-Impunity-April-2012.pdf. On this point, see also Lisa Ginsborg, “One Step Forward, Two Steps Back: The Security Council, ‘Foreign Terrorist Fighters’ and Human Rights”, in Manfred Novak and Anne Charbod (eds), Using Human Rights to Counter Terrorism, Edward Elgar Publishing, Cheltenham, 2018, pp. 203–204.

41 Philips, Brian J., “What is a Terrorist Group? Conceptual Issues and Empirical Implications”, Terrorism and Political Violence, vol. 27, no. 2, 2015, pp. 225–226CrossRefGoogle Scholar.

42 Kent Roach, The 9/11 Effect: Comparative Counter-Terrorism, Cambridge University Press, Cambridge, 2012, p. 28. For a more detailed assessment and criticism of the listing system that exists at the level of the UN, see, for example, Lisa Ginsborg, “The United Nations Security Councils Counter-Terrorism ISIL (Daesh) and Al-Qaida Sanctions Regime”, in Ben Saul (ed.), Research Handbook on International Law and Terrorism, Edward Elgar Publishing, Cheltenham, 2020, pp. 550–563.

43 ICRC, “International Humanitarian Law and the Challenges of Contemporary Armed Conflict. Recommitting to the Protection in Armed Conflict on the 70th Anniversary of the Geneva Conventions”, October 2019, p. 58 (hereafter ICRC Challenges Report 2019). See also Stéphane Ojeda, “Global Counter-Terrorism Must not Overlook the Rules of War”, Humanitarian Law & Policy, 13 December 2016, available at: https://blogs.icrc.org/law-and-policy/2016/12/13/global-counter-terrorism-rules-war/.

44 ICRC Challenges Report 2015, above note 15, p. 18.

45 M. Macmillan, above note 22, p. 313.

46 H.-P. Gasser, above note 20, p. 562.

47 ICRC, Customary IHL Database, Rule 2 (applicable in both international armed conflicts and non-international armed conflicts), available at: https://ihl-databases.icrc.org/customary-ihl/eng/docs/v1_rul_rule2 (emphasis added). See also Protocol Additional (I) to the Geneva Conventions of 12 August 1949, and Relating to the Protection of Victims of International Armed Conflicts, 1125 UNTS 3, 8 June 1977 (entered into force 7 December 1978) (AP I), Art. 51(2); Protocol Additional (II) to the Geneva Conventions of 12 August 1949, and Relating to the Protection of Victims of Non-International Armed Conflicts, 1125 UNTS 609, 8 June 1977 (AP II), Art. 13(2); and Geneva Convention (IV) relative to the Protection of Civilian Persons in Time of War of 12 August 1949, 75 UNTS 287 (entered into force 21 October 1950) (GC IV), Art. 33.

48 ICRC Challenges Report 2015, above note 15, p. 18.

49 S. Ojeda, above note 43. On this point, see also D. McKeever, above note 19, p. 52.

50 O. Venet, above note 35, p. 169. See also H.-P. Gasser, above note 20, p. 566; and Proceedings of the Bruges Colloquium: Terrorism, Counter-Terrorism and International Humanitarian Law, 20–21 October 2016, Collegium, No. 47, Autumn 2017, pp. 43–44.

51 On this point, see, more particularly, J. K. Kleffner, “From ‘Belligerents’ to ‘Fighters’ and Civilians Directly Participating in Hostilities – On the Principle of Distinction in Non-International Armed Conflicts One Hundred Years After the Second Hague Peace Conference”, Netherlands International Law Review, Vol. 54, 2007, pp. 321–323.

52 S. Krähenmann, above note 22, p. 20. On this point, see also, more particularly, Højfeldt, H., “Prohibiting Participation in Armed Conflict”, The Military Law and the Law of War Review, vol. 54, 2015–2016, p. 31Google Scholar.

53 See Art. 6(5) of AP II, stating that “at the end of the hostilities, the authorities in power shall endeavor to grant the broadest possible amnesty to persons who have participated in the armed conflict”. See also ICRC, Customary IHL database, Rule 159, available at: https://ihl-databases.icrc.org/customary-ihl/eng/docs/v1_rul_rule159. The granting of amnesties to those who have merely participated in hostilities has also been encouraged by various UN bodies, including the UNSC, as well as by NATO and the EU; see https://www.icrc.org/en/document/amnesties-and-ihl-purpose-and-scope.

54 For a more in-depth assessment of the Maher and Context cases and the relationship between combatant immunity, see. H. Cuyckens and C. Paulussen, above note 17, pp. 548–551.

55 Ibid., pp. 550–551.

56 Qualification as a terrorist organization is made here on the basis of the UNSC's list of terrorist organizations; available at: https://scsanctions.un.org/consolidated/#alqaedaent.

57 Ali, A., “La risposta della communità internazionale al fenomeno dei foreign terrorist fighters”, La commmunità internazionale, vol. 2, 2015, p. 181Google Scholar. See, also, H. Cuyckens and C. Paulussen, above note 17, p. 541.

58 It is included on the UNSC's list of terrorist organizations. For the qualification of Jabhat Al Nusra as a party to the conflict in Syria, see, for example, T. Gill, “Classifying the Conflict in Syria”, International Law Studies (Naval War College), Vol. 92, 2016, p. 374.

59 On this point, also see A. Sánchez Frías, above note 24, p. 99.

60 UNSC Resolution 1566 (2004), adopted 8 October 2004, para. 3.

61 UNSC Resolution 1373 (2001), adopted 28 September 2001, para. 2(e).

62 UNSC Resolution 2178 (2014), above note 12.

63 M. Macmillan, above note 22, p. 313.

64 Ibid.

65 Eurojust Genocide Network Report on Cumulative Prosecution, above note 16, p. 7.

66 EU directive 2017/541, above note 12, art. 3.

67 Ibid., arts 5 to 11.

68 Ibid., art. 4.

69 Ibid., art. 2(3).

70 For the UNSC's list of terrorist organizations, see United Nations Security Council Consolidated List, available at: https://scsanctions.un.org/consolidated/#alqaedaent.

71 Christophe Paulussen and Kate Pitcher, “Prosecuting (Potential) Foreign Fighters: Legislative and Practical Challenges”, ICCT Research Paper, 2018, p.25, available at: https://icct.nl/app/uploads/2018/01/ICCT-Paulussen-Pitcher-Prosecuting-Potential-Foreign-Fighters-Legislative-Practical-Challenges-Jan2018.pdf, p. 16.

72 R. J. Speerstra and M. Pennewaard, “Jitse Akse niet vervolgd voor het doden van IS-strijders”, Algemeen Dagblad, 22 June 2016, available at: https://www.ad.nl/nieuws/jitse-akse-niet-vervolgd-voor-het-doden-van-is-strijders~a37f487e. On this case, see also C. Paulussen and K. Pitcher, above note 71, p. 25; and J. Geneuss, above note 37, p. 358.

73 C. Paulussen and K. Pitcher, above note 71, p. 25; and J. Geneuss, above note 37, p. 358.

74 For a historical overview in support of the point that the FF phenomenon is neither new nor uniquely Islamic, see Malet, David, “Why Foreign Fighters? Historical Perspectives and Solutions”, Orbis, vol. 54, no. 1, 2010, pp. 97–114CrossRefGoogle Scholar.

75 ICRC Challenges Report 2019, above note 43, p. 62.

76 P. Gaeta, “War Crimes and Other International ‘Core’ Crimes”, in A. Clapham and P. Gaeta (eds), The Oxford Handbook of International Law in Armed Conflict, Oxford University Press, Oxford, 2014, p. 750. See also van der Wilt, Harmen, “War Crimes and the Requirement of a Nexus with an Armed Conflict”, Journal of International Criminal Justice, vol. 10, no. 5, 2012, pp. 1113–1114CrossRefGoogle Scholar; Cassese, Antonio, “The Nexus Requirement for War Crimes”, Journal of International Criminal Justice, 2012, Vol. 10, No. 5, pp. 1395–1417CrossRefGoogle Scholar; and Guénaël Mettraux, “Nexus with Armed Conflict”, in Antonio Cassese (ed.), Oxford Companion to International Criminal Justice, Oxford University Press, Oxford, 2009, pp. 435–436.

77 International Criminal Tribunal for the former Yugoslavia, Appeals Chamber, Prosecutor v. Kunarac and others, IT-96-23, 12 June 2002, para. 59.

78 Anthony Dworkin, “A Tribunal for ISIS Fighters?”, ECFR Commentary, 31 May 2019, available at: https://ecfr.eu/article/commentary_a_tribunal_for_isis_fighters/.

79 Francesca Capone, “Is Trump Right? Foreign Fighters and the States’ Obligation to Repatriate Them”, Verfassungsblog, 10 March 2019, available at: https://verfassungsblog.de/is-trump-right-foreign-fighters-and-the-states-obligation-to-repatriate-them/.

80 Rachel Behring, “One-Eyed Prosecution? On the Possibility to Restrict the Personal Jurisdiction of an International Ad Hoc-Tribunal for ISIS-Fighters?”, Volkerrechtblog, 4 February 2020, available at: https://voelkerrechtsblog.org/de/one-eyed-prosecution/.

81 P. A. Nollkaemper, “Advies Internationaal Tribunaal ISIS”, 22 July 2019, available at: https://www.rijksoverheid.nl/documenten/rapporten/2019/07/24/advies-internationaal-tribunaal-isis, p. 3.

82 Ibid., p. 3. See also “Statement of the Prosecutor of the International Criminal Court, Fatou Bensouda, on the Alleged Crimes Committed by ISIS”, 8 April 2015, available at: https://www.icc-cpi.int/Pages/item.aspx?name=otp-stat-08-04-2015-1.

83 P. A. Nollkaemper, above note 81, p. 15.

84 R. Behring, above note 80.

85 T. Mehra and C. Paulussen, above note 7.

86 P. A. Nollkaemper, above note 81, raises a similar point in the above-mentioned legal advice.

87 This does not mean that when the act of terrorism in question also meets the definition of war crimes, crimes against humanity or genocide as defined in the Rome Statute they would not be able to still be prosecuted under the international criminal law framework. But terrorism does not constitute an international core crime as such; M. Macmillan, above note 22, p. 312. For a more in-depth assessment of this question, see, for example, R. Arnold, “Terrorism, War Crimes and the International Criminal Court, in Ben Saul (ed.), Research Handbook on International Law and Terrorism, Edward Elgar, Cheltenham, 2020, pp. 271–284.

88 On this point, see, for example, Helen Brady and Fabricio Guariglia, “An Insider's View: Consistency and Transparency While Preserving Prosecutorial Discretion”, International Criminal Justice Today, 15 December 2016, available at: https://www.international-criminal-justice-today.org/arguendo/an-insiders-view/.

89 T. Mehra and C. Paulussen, above note 7.

90 Tanya Mehra, “Bringing (Foreign) Terrorist Fighters to Justice in a Post-ISIS Landscape. Part I: Prosecution by Iraqi and Syrian Courts”, ICCT Perspectives, 22 December 2017, available at: https://icct.nl/publication/bringing-foreign-terrorist-fighters-to-justice-in-a-post-isis-landscape-part-i-prosecution-by-iraqi-and-syrian-courts/. See also, Roger Lu Philips, “A Tribunal for ISIS Fighters – A National Security and Human Rights Emergency”, Just Security, available at: https://www.justsecurity.org/75544/a-tribunal-for-isis-fighters-a-national-security-and-human-rights-emergency/.

91 Tanya Mehra, “Bringing (Foreign) Terrorist Fighters to Justice in a Post-ISIS Landscape. Part II: Prosecution by Foreign National Courts”, ICCT Perspectives, 12 January 2018, available at: https://icct.nl/publication/bringing-foreign-terrorist-fighters-to-justice-in-a-post-isis-landscape-part-ii-prosecution-by-foreign-national-courts/.

92 M. Coker and F. Hassan, above note 8.

93 United Nations Counter-Terrorism Implementation Task Force (Working Group on Promoting and Protecting Human Rights and the Rule of Law while Countering Terrorism), “Guidance to States on Human Rights-Compliant Responses to the Threat Posed by Foreign Fighters”, New York, 2018, p. 38 (hereafter Guidance on HR-Compliant Responses to the Threat Posed by FFs).

94 Human Rights Watch (HRW) report, “‘These are the Crimes we are Fleeing’: Justice for Syria in Swedish and German Courts”, Human Rights Watch, 3 October 2017, available at: https://www.hrw.org/report/2017/10/03/these-are-crimes-we-are-fleeing/justice-syria-swedish-and-german-courts, p. 4.

95 T. Mehra, above note 90.

96 See, for example, F. Capone, above note 79; and R. L. Philips, above note 90. See also HRW report, “Flawed Justice: Accountability for ISIS crimes in Iraq”, Human Rights Watch, 5 December 2017, available at: https://www.hrw.org/report/2017/12/05/flawed-justice/accountability-isis-crimes-iraq.

97 T. Mehra, above note 90.

98 Dan Sabbagh, “Syrian Kurds to Put Isis Fighters from Dozens of Countries on Trial”, The Guardian, 6 February 2020, available at: https://www.theguardian.com/world/2020/feb/06/syrian-kurds-to-put-isis-fighters-from-dozens-of-countries-on-trial.

99 Tanya Mehra and Matthew Wentworth, “New Kid on the Block: Prosecution of ISIS Fighters by the Autonomous Administration of North and East Syria”, ICCT Perspective, 16 March 2021, available at: https://icct.nl/publication/prosecution-of-isis-fighters-by-autonomous-administration-of-north-east-syria/ .

100 For the qualification of the SDF as a NSAG, see RULAC, Non-International Armed Conflicts in Syria, available at: https://www.rulac.org/browse/conflicts/non-international-armed-conflicts-in-syria#collapse5accord.

101 This question is more particularly raised in Hannes Jöbstl, “Outsourcing Justice: State Obligations and the Prosecution of Foreign Fighters by Armed Groups in Syria”, Armed Groups and International Law Blog, 6 April 2020, available at: https://armedgroups-internationallaw.org/2020/04/06/outsourcing-justice-state-obligations-and-the-prosecution-of-foreign-fighters-by-armed-groups-in-syria/.

102 Geneva Call, “Administration of Justice by Armed Non-State Actors”, Report from the 2017 Garance Talks, available at: https://genevacall.org/wp-content/uploads/dlm_uploads/2018/09/GaranceTalks_Issue02_Report_2018_web.pdf, p. 7.

103 T. Mehra and M. Wentworth, above note 99.

104 Ezequiel Heffes, “Administration of Justice by Armed Groups: Some Legal and Practical Concerns”, Humanitarian Law & Policy, 22 November 2018, available at: https://blogs.icrc.org/law-and-policy/2018/11/22/administration-of-justice-armed-groups-some-legal-practical-concerns/.

105 Ibid.

106 Ibid.

107 ICRC, Commentary of 2016. Article 3: Conflicts not of an International Character, available at: https://ihl-databases.icrc.org/applic/ihl/ihl.nsf/Comment.xsp?action=openDocument&documentId=59F6CDFA490736C1C1257F7D004BA0EC, para. 689.

108 E. Heffes, above note 104.

109 T. Mehra and M. Wentworth, above note 99.

110 T. Mehra, above note 91.

111 Francesco Ragazzi and Josh Walmsley, “The Return of Foreign Fighters to EU Soil: Ex-Post Evaluation”, European Parliamentary Research Service Study, available at: www.europarl.europa.eu/RegData/etudes/STUD/2018/621811/EPRS_STU(2018)621811_EN.pdf, Part II, p. 43.

112 With relation to the first point, see F. Ragazzi and J. Walmsley, above note 111, p. 43. Concerning the second claim, see, more particularly, H. Cuyckens and C. Paulussen, above note 17, p. 561.

113 Eurojust Genocide Network Report on Cumulative Prosecution, above note 16, p. 5.

114 Ibid., p. 7. See also C. Paulussen and K. Pitcher, above note 71, p. 16.

115 Europol, “European Union Terrorism Situation and Trend Report (Te-Set) 2020”, available at: https://www.europol.europa.eu/activities-services/main-reports/european-union-terrorism-situation-and-trend-report-te-sat-2020, p. 28.

116 F. Ragazzi and J. Walmsley, above note 111, p. 44. See also “ISIS Foreign Fighters After the Fall of the Caliphate”, above note 6.

117 Europol, above note 115, p. 25.

118 For Germany, see for example, Prosecutor v. Abdelkarim El. B., Higher Regional Court (Frankfurt am Main), Judgment, 8 November 2016, Case number 5-3 StE 4/16 – 4 – 3/16. For the Netherlands, see Prosecutor v. Oussama A. (District Court of The Hague, 23 July 2019). The English translation is available at: http://deeplink.rechtspraak.nl/uitspraak?id=ECLI:NL:RBDHA:2019:10647.

119 Abdelkarim El. B., above note 118; and Oussama A., above note 118, § 5.4.

120 District Court of the Hague, case number 09/748012-19, 29 June 2021, available in Dutch at: https://uitspraken.rechtspraak.nl/inziendocument?id=ECLI:NL:RBDHA:2021:6620&showbutton=true.

121 Ibid.

122 Case number 09/748012-19, above note 120, § 6.4.2.

123 Ibid.

124 Ibid.

125 Ibid.

126 F. Ragazzi and J. Walmsley, above note 111, p. 45.

127 For pillage, see Higher Regional Court of Stuttgart, 5 July 2019, Case No. 5-2 StE 11/18; Higher Regional Court of Düsseldorf, 4 December 2019, Case No. 2 StS 2/19; and Federal Court of Justice (GE), Ruling on Pre-Trial Detention, 4 April 2019, Case No. BGH AK 12/19. For recruitment of child soldiers, see Federal Court of Justice (GE), 17 October 2019, Case No. AK 56/19. For the killing of person protected under IHL, see Der Generalbundesanwalt beim Bundesgerichtshof, Presse: “Anklage gegen ein mutmaßliches Mitglied der ausländischen terroristischen Vereinigung „Islamischer Staat (IS)“ wegen Mordes und der Begehung eines Kriegsverbrechens erhoben”, 28 December 2018, available at: www.generalbundesanwalt.de/SharedDocs/Pressemitteilungen/DE/2018/Pressemitteilung-vom-28-12-2018.html?nn=478298. See also, more generally, Eurojust Genocide Network Report on Cumulative Prosecution, above note 16, pp. 17–20.

128 Eurojust Genocide Network Report on Cumulative Prosecution, above note 16, pp. 17–18.

129 Higher Regional Court of Düsseldorf, above note 127, para. 251.

130 H.-P. Gasser, above note 20, p. 566. See also Proceedings of the Bruges Colloquium, above note 50, pp. 43–44 and O. Venet, above note 35, p. 169.

131 Proceedings of the Bruges Colloquium, above note 50, pp. 43–44.

132 Ibid.

133 Guidance on HR-Compliant Responses to the Threat Posed by FFs, above note 93, p. 38.

134 On these points, see, more particularly, Eurojust/Genocide Network, “Prosecuting War Crimes of Outrage Upon Personal Dignity Based on Evidence From Open Sources – Legal Framework and Recent Developments in the Member States of the European Union”, The Hague, February 2018; as well as B. van Ginkel and C. Paulussen, “The Role of the Military in Securing Suspects and Evidence in the Prosecution of Terrorism Cases before Civilian Courts: Legal and Practical Challenges”, ICCT Research Paper, 7 May 2015, available at: http://www.icct.nl/download/file/ICCT-Van-Ginkel-Paulussen-The-Role-Of-The-Military-In-Securing-Suspects-And-Evidence-In-The-Prosecution-Of-Terrorism-Cases-Before-Civilian-Courts.pdf.

135 Eurojust Genocide Network Report on Cumulative Prosecution, above note 16, p. 5.

136 UNSC Resolution 2379 (2017), adopted 21 September 2017, para. 2.

137 T. Mehra and C. Paulussen, above note 7.

138 The Soufan Center, “Bringing Terrorists to Justice: Prosecuting ISIL War Crimes and Terrorism”, June 2021, available at: https://thesoufancenter.org/research/bringing-terrorists-to-justice-prosecuting-isil-war-crimes-and-terrorism/, p. 1.

139 T. Mehra, “Bringing (Foreign) Terrorist Fighters to Justice in a Post-ISIS Landscape. Part III: Collecting Evidence from Conflict Situations”, ICCT Perspectives, 12 June 2018, available at: https://icct.nl/publication/bringing-foreign-terrorist-fighters-to-justice-in-a-post-isis-landscape-part-iii-collecting-evidence-from-conflict-situations/.

140 Ibid.

141 See https://cijaonline.org/key-successes. CIJA is also listed amongst the specialized civil society organizations that may play a role in the prosecution of FFs in the Eurojust and Genocide Network report on cumulative prosecution; see Eurojust Genocide Network Report on Cumulative Prosecution, above note 16, p. 25.

142 See https://cijaonline.org/key-successes.

143 See Oussama A., above note 118, footnote 48.

144 See also, more generally, Eurojust Genocide Network Report on Cumulative Prosecution, above note 16, p. 25. See also T. Mehra, above note 139.

145 H. Cuyckens and C. Paulussen, above note 17, p. 563. See also Guidance on HR-Compliant Responses to the Threat Posed by FFs, above note 93, p. 36.

146 Guidance on HR-Compliant Responses to the Threat Posed by FFs, above note 93, p. 36.

147 Customary rule 158, available at: https://ihl-databases.icrc.org/customary-ihl/eng/docs/v1_rul_rule158. On this point, see also Jöbstl, above note 101.

148 Ibid.

149 Eurojust Genocide Network Report on Cumulative Prosecution, above note 16, p. 5.

150 On this point, see also, more particularly, Braun, Kerstin, “‘Home, Sweet Home’: Managing Returning Foreign Terrorist Fighters in Germany, the United Kingdom and Australia”, International Community Law Review, Vol. 20, No. 3–4, 2008, pp. 311–346CrossRefGoogle Scholar.