cern at the use of detained children for information-gathering purposes, and emphasizes that children who have been recruited in violation of applicable international law by armed forces and armed groups and are accused of having committed crimes during armed conflicts should be treated primarily as victims of violations of international law.138 According to the Paris Principles on Children Associated with Armed Forces or Armed Groups, such children should be considered victims of violations of their rights, and of offences under international law, as well as their environment, in which they were coerced in some form.139 Consequently, States should ensure that such children can claim their rights and seek protection in a non-hostile environment.140 States should prioritize provision of psychosocial rehabilitation and social reintegration services for these children.141 Those who exploit, recruit, train and use children should be held criminally responsible.142 138 Security Council resolution 2427 (2018), preambular para. 11, para. 20. 139 The Paris Principles Groups (2007), para. 3.6. “Children who are accused of crimes under international law allegedly committed while they were associated with armed forces or armed groups should be considered primarily as victims of offences against international law; not only as perpetrators. They must be treated in accordance with international law in a framework of restorative justice and social rehabilitation, consistent with international law which offers children special protection through numerous agreements and principles.” 140 Committee on the Rights of the Child, general comment No. 13 (2011), para. 52. 1.3.2 The Need for Individualized Assessments 79. The conclusion about what may be in a particular child’s best interests necessarily varies. Therefore, it is critical that each child be assessed individually according to his or her situation, rights and needs in a multidisciplinary manner.143 This is also be critical to devising effective measures for each child, including for rehabilitation and reintegration, while ascertaining any security concerns a child may pose. 80. Addressing the needs of children affected by the foreign fighter phenomenon, including their reintegration into a community, should always be preceded by an individualized best-interests assessment. The assessment should be done in a friendly and safe atmosphere. Professionals trained in relevant human and social development fields, such as child psychology, child development, should undertake the assessment in a multidisciplinary manner.144 The assessment should include an examination of the child’s health, potential impacts of gender-based violence and her or his family and community environments and attachments, among other things.145 Such assessments should be undertaken in a cultural, gender and age-sensitive manner. It is also important to pay special attention to the atrocities that children may have witnessed and remain rooted in the child’s best interests, regardless of national considerations or priorities.146 81. Children affected by the foreign fighter phenomenon may have been forced to participate in military training or may have been married at a very young age. They may have experienced, 141 Convention on the Rights of the Child, arts. 39, 40(1), Optional Protocol to the Convention on the Rights of the Child on the involvement of children in armed conflict (2000), art. 6(3). See also Security Council resolution 2427, which urges Member States to consider non-judicial measures that focus on rehabilitation and reintegration (para. 21), and encourages Member States to focus on long-term and sustainable reintegration and rehabilitation opportunities for children affected by armed conflict (para. 26). 143 Committee on the Rights of the Child, general comment No. 14 (2013), para. 76. 142 Security Council resolution 2427 (2018), para. 30. 146 Ibid., para. 7.31. 36. 144 Ibid., para. 94. 145 The Paris Principles (2007), paras. 6.35.2, 7.69.0, 7.72.