nationalities. Some State practice also differentiates between “citizens by birth and “naturalised citizens . Such practices dangerously result in two different tiers of citizenship, whereby, for example, someone who has two nationalities, or is a naturalised citizen, is more vulnerable to being deprived of their nationality than someone who has only one citizenship or is a citizen by birth. While such discrimination is purportedly justified on the basis of “protecting against statelessness , it is important to note that “protection of mono nationals from statelessness cannot be a legal justification or defence for exposing dual nationals to citizenship stripping .109 62. Such discrimination between different classes of citizen is contrary to the principle of equality before the law and equal protection of the law, enshrined in Article 26 of the ICCPR and a number of other instruments. 63. The jurisprudence and guidance of UN treaty bodies and Special Procedures situates such differential treatment as a form of direct discrimination. For example, the CERD Committee has raised concern about making distinctions between dual and mono-nationals,110 as they “could give rise to discriminatory practices contrary to CERD .111 Further, the Working Group on Arbitrary Detention has held that discrimination against dual nationals "aims towards or can result in ignoring the equality of human beings .112 The Working Group also concluded that Iran's targeting of dual nationals constitutes direct discrimination on the basis of "national or social origin".113 As set out by the UN Special Rapporteur on contemporary forms of racism, racial discrimination, xenophobia and related intolerance: “Applying the Working Group's finding to the citizenship-stripping context mandates that States never use a mono-/dual-citizen distinction, as this distinction prevents dual nationals from enjoying equal treatment before the law and equal enjoyment of their human rights."114 64. At the European regional level, the ECN specifies that this inequality between nationals is discriminatory, stating that “[e]ach State Party shall be guided by the principle of nondiscrimination between its nationals, whether they are nationals by birth or have acquired its nationality subsequently Article . The European Court of Human Rights has also held that any arbitrary distinctions between those who acquired citizenship through naturalisation and those who acquired citizenship through birth can result in a violation of the prohibition of discrimination under the European Convention on Human Rights.115 65. Principles 9.7 (on the rights of the child) and 9.8 (on derivative loss of nationality) together set out international law provisions related to the child’s right to preserve their nationality, and to not be deprived of their nationality as a result of a parent or guardian’s nationality being deprived. The prohibition of discrimination by association is integrated within the general anti-discrimination clause of the CRC (Article 2): 109 UN Special Rapporteur on contemporary forms of racism, racial discrimination, xenophobia and related intolerance, ’Amicus Brief before the Dutch Immigration and Naturalisation Service‘ October 2018), para. 40. 110 CERD/C/75/D/42/2008; CERD/C/RWA/CO/18-20. 111 CERD/C/RWA/CO/18-20, paras. 8-9. 112 Working Group on Arbitrary Detention opinion No. 49/2017, paras. 3(e), 43-45. 113 Working Group on Arbitrary Detention opinion No. 7/2017, 39-40; opinion No. 49/2017, 43-45; opinion No. 28/2016, paras. 45-49. 114 UN Special Rapporteur on contemporary forms of racism, racial discrimination, xenophobia and related intolerance, ’Amicus Brief before the Dutch Immigration and Naturalisation Service’ October 2018), para. 38. 115 Biao v. Denmark, Judgment (Merits and Just Satisfaction) of May 5, 2016, App. 38590/10. 42