Citizenship Loss and Deprivation in the European Union (27 + 1) obligations were quite light in the initial international framework. Manley O. Hudson, the special rapporteur on nationality including statelessness to the UN International Law Commission in the 1950s, wrote that the withdrawal of nationality based on “prolonged absence abroad […] may be regarded as giving effect to the national’s desire for expatriation.”63 Accordingly, articles 8(4) and (5) of the 1961 Convention on the Reduction of Statelessness do not limit the power of States to withdraw nationality, even if it could lead to statelessness, in two cases: “4. A naturalized person may lose his nationality on account of residence abroad for a period, not less than seven consecutive years, specified by the law of the Contracting State concerned if he fails to declare to the appropriate authority his intention to retain his nationality. 5. In the case of a national of a Contracting State, born outside its territory, the law of that State may make the retention of its nationality after the expiry of one year from his attaining his majority conditional upon residence at that time in the territory of the State or registration with the appropriate authority.” For the 1961 Convention, expatriation is thus a formal case that could lead to statelessness. These international provisions were adopted under the influence of the British representatives, whose legislation at that time specifically allowed for the revocation of the nationality of naturalised citizens after seven years of residence abroad, and the non-transmission of nationality by descent in case of residence abroad, without any regard for statelessness prevention. The 1997 European Convention on Nationality now provides for a stronger and wider protection. Article 7(1)(e) states that “A State Party may not provide in its internal law for the loss of its nationality ex lege or at the initiative of the State Party except in the following cases: […] lack of a genuine link between the State Party and a national habitually residing abroad,” and article 7(3) specifies that a State cannot use that mode of loss “if the person concerned would thereby become stateless.” The development of international law on nationality, especially in the European legal order therefore seems to point towards full statelessness prevention in the case of loss of nationality due to residence abroad. The Explanatory Report to the European Convention on Nationality states that one of the aims of this provision is “to allow a State, which so wishes, to prevent its nationals habitually living abroad to retain its nationality generation after generation,” but only when statelessness is not at stake. Therefore, for the writers of the Explanatory Report, “lack of a genuine link” refers primarily to “dual nationals habitually residing abroad […] for generations”; proof of this lack of a genuine link can be identified through, inter alia, the “omission” of “i. registration; ii. application for identity or travel documents; iii. declaration expressing the desire to conserve the nationality of the State Party.”64 The European Union legal order has recently improved the protection of individuals against this mode of loss. In the recent Tjebbes case, the Court of Justice of the European Union (CJEU) investigated the situation of four women who lost their Dutch nationality, and therefore EU citizenship, after living more than ten years outside the borders of the EU in countries of which they were also nationals (one in Canada, two in Switzerland, and one in Iran).65 The conclusion of the court, now binding for every Member State of the EU, was first, that “it is legitimate for a Member State to take the view that nationality is the expression of a genuine link between it and its nationals” and, second, that authorities must “[have] due regard to the principle of proportionality so far as concerns the consequences of that loss for the situation of the person concerned and, if relevant, for that of the members of his or her family, from the point of view of EU law.” This principle of proportionality strikes a balance between “the objective pursued by the national legislature” on the one hand, and “the normal development of [the individual’s] family and professional life” on the other hand. The Court also ruled that the assessment of proportionality must take into account the provisions of the Charter of Fundamental 63 Hudson, M. O. (1952). “Nationality, Including Statelessness.” Yearbook of the International Law Commission (II): 4–24. 64 Explanatory Report to the European Convention on Nationality, § 69-71. 65 M.G. Tjebbes and Others v Minister van Buitenlandse Zaken, ECLI:EU:C:2019:189. European University Institute 15