European States’ Obligations to Repatriate the Children Detained in Camps in Northeast Syria a broader sense in light of the relevant international standards and in accordance with the best interest of the child.503 To justify the repatriation of children without primary caregivers, European States mainly invoke national security arguments (see Section I.B. and C. above). While States have a certain measure of discretion when evaluating threats to national security and how to combat them, they are required to verify that threats have a reasonable basis in fact. 504 In particular, there must be a reasonable relationship of proportionality between the restrictions imposed and the legitimate aim of protecting national security.505 The margin of appreciation of competent national authorities in regard to the right to family life varies in accordance with the nature of the issues and the importance of the interests at stake. 506 However, the blanket arguments put forward by some European States invoking national security as a justification for not repatriating the primary caregivers (see section I.C.), which ignore the child’s best interests principle and restrict children’s right to family life, fall short of these requirements. Reports indicate that a high proportion of women in the camps were either never committed to ISIS or are no longer committed, or that they do not pose an overwhelming security risk to European countries or a risk of abusing or neglecting their children.507 Notably, for those who remain committed to ISIS ideology, it is now widely accepted that their repatriation, prosecution, rehabilitation, and reintegration remain the most effective and feasible option for ensuring sustainable long-term security and that leaving the perceived threat outside of the borders may even be counter-productive.508 503 ECtHR, “Schneider v. Germany”, Application No. 17080/07, 15 December 2011, (contact between a child and non-legally recognised father), para. 79-82. HRComm, “General Comment No. 16”, 1988, para. 5, noting that the term “family” should be given a broad interpretation to include those understood as family in the society of the State concerned. HRComm, “General Comment No. 19: Article 23 (The Family) Protection of the Family, the Right to Marriage and Equality of the Spouses”, 27 July 1990, para. 2; CommRC, “Concluding Observations, Nepal”, CRC/C/15/Add.261, 21 September 2005, para. 51-52, noting that adequate alternative care for a child includes placement with their extended family. UNICEF, “Implementation Handbook for the Convention on the Rights of the Child”, September 2007, p. 124. 504 ECtHR, “Janowiec and Others v. Russia” Application No. 55508/07 and 29520/09, 21 October 2013, para. 213-214. See also: CoE, “National security and European case-law”, 2013, p. 3. 505 ECtHR, “Konstantin Markin v. Russia” Application No. 30078/06, 22 March 2012, para. 137. 506 ECtHR, “Sahin v. Germany”, Application No. 30943/96, 8 July 2003, para. 65. 507 RSI, “Europe’s Guantanamo: The Indefinite Detention of European Women and Children in North East Syria,” 2020, para. 95. 508 Open Letter from National Security Professionals to Western Governments, “Unless We Act Now, the Islamic State Will Rise Again”, 11 September 2019. OSCE/ODIHR, “Guidelines for Addressing the Threats and Challenges of ‘Foreign Terrorist Fighters’ within a Human Rights Framework”, 2018, p. 50.. 85