this one) are recognised to be customary in nature.24 14. Secondly, the consistent inclusion of the prohibition in global and regional human rights treaties provides further support for the conclusion that it constitutes a principle of CIL. Not only do those treaties demonstrate State practice across almost every continent, they also evidence opinio juris by reflecting States’ repeated recognition of the normative force and binding character of the prohibition. If the UDHR itself did not crystallise custom, the treaties that followed it certainly did. 15. Thirdly, the prohibition has been recognised as customary by international courts,25 individual judges,26 and UN bodies.27 The UN General Assembly, in particular, has characterised it as a “fundamental principle of international law” 28 in a resolution which, having been adopted without objection, constitutes important evidence of both State practice and opinio juris. As one academic concluded after an extensive survey of the law, “the prohibition of arbitrary deprivation of nationality is now a well-established customary norm of international law”.29 F. The content of the prohibition 16. There are two central words on which the interpretation of the provision depends: “arbitrary” and “deprivation”. 17. The reference to “deprivation” is straightforward. It implies an act of taking without the See Tehran Hostages Case (United States v Iran) [1980] ICJ Rep. 3, p. 42, para. 91, which applies the UDHR’s “fundamental principles” as law. 24 Eritrea-Ethiopia Claims Commission, Partial Award (Civilian Claims – Eritrea’s Claims 15, 16, 23 and 27-32) (2004) 26 UNRIAA 195, para. 57 (the Commission accepted that the rules cited, including Article 15.2 of the UDHR, were customary); Proposed Amendments to the Naturalization Provision of the Constitution of Costa Rica, Inter-American Court of Human Rights, Advisory Opinion OC-4/84, 19 January 1984, Ser. A, No. 4, paras 33-34 (the Court referred to Article 15 of the UDHR in its recitation of “international law” on the right to nationality); Case of Expelled Dominicans and Haitians v Dominican Republic, Inter-American Court of Human Rights, Judgment, 28 August 2014, Ser. C, No. 282, para. 253 (referencing the “fundamental right of the human person” established by instruments including the UDHR); see also Anudo Ochieng Naudo v United Republic of Tanzania, African Court on Human and Peoples’ Rights, Judgment, 22 March 2018, para. 76 (regarding the status of the UDHR as customary generally, in the context of considering Article 15(2)). 25 Application for Review of Judgment No. 333 of the United Nations Administrative Tribunal [1987] ICJ Rep. 18, p. 173 (Dissenting Opinion of Judge Evensen, citing Article 15.2 of the UDHR as one of the “basic principles of law spelt out in the ... Declaration”); Judge J. Crawford (ed), Brownlie’s Principles of Public International Law (2019), p. 508, who accepts that there is “some basis for holding it to be a rule of customary international law”. As regards nationality more generally, see Nottebohm Case [1955] ICJ Rep. 4, p. 63 (Dissenting Opinion of Judge ad hoc Guggenheim referred to the “basic principle embodied in Article 15(1) of the Universal Declaration of Human Rights”). 26 See, e.g., ‘Arbitrary deprivation of nationality: Report of the Secretary-General’, UN Doc. A/HRC/10/34, 26 January 2009, para. 48; UN Counter-Terrorism Implementation Task Force, ‘Guidance to States on human rightscompliant responses to the threat posed by foreign fighters’, 2018, para. 40 (“The prohibition of arbitrary deprivation of nationality has been widely recognized as a norm of customary international law”); UNHCR, ‘UNHCR Guidelines on Statelessness No. 5’ (May 2020), para. 85 (referring to the “strong international consensus that the right to nationality, and relatedly, the prohibition of arbitrary deprivation of nationality are fundamental principles of international law”). 27 28 UNGA, Resolution 50/152, UN Doc. A/RES/50/152, 9 February 1996, para. 16. T. Molnár, ‘The Prohibition of Arbitrary Deprivation of Nationality under International Law and EU Law: New Perspectives’ (2015) Hungarian Yearbook of International Law and European Law 67, p. 74; see also A. Edwards, ‘The Meaning of Nationality’ in A. Edwards and L. van Waas (eds), Nationality and Statelessness under International Law (2014), pp. 25-26. 29 6