144 Tjebbes and Others v Minister van Buitenlandse Zaken did, as this can be seen as an expression of lack of a genuine link between citizen and state which underlies the bond of nationality.22 However, such loss of nationality would be inconsistent with the principle of proportionality if the national rules do not allow for an individual examination of the consequences of that loss for the persons concerned under EU law at any time by the competent national authorities and courts, including—where appropriate—the possibility to recover nationality ex tunc for the person concerned.23 The Court specifies that this examination entails an individual assessment of whether the loss of EU citizenship disproportionately affects normal development of his or her family and professional life according to EU law with regard to the objective pursued by the national authorities.24 As part of this proportionality test, national authorities and courts must ensure that the loss of nationality is in line with the rights of the EU Charter of Fundamental Rights, in particular the right to respect for family life and the obligation to take into account the best interests of the child.25 According to the CJEU, relevant circumstances for the proportionality test include whether ‘the person concerned would be exposed to limitations when exercising his or her right to move and reside freely within the territory of the Member States, including, depending on the circumstances, particular difficulties in continuing to travel to the (…) [EU] in order to retain genuine and regular links with members of his or her family, to pursue his or her professional activity or to undertake the necessary steps to pursue that activity. (…)’26 On the question of the loss of nationality by a minor as a consequence of loss of nationality by a parent, the Court holds that it is in principle legitimate for a state to want to preserve unity of nationality within a family by way of a provision such as the Netherlands made.27 However, the relevant national authorities should consider in an individual assessment possible circumstances that demonstrate that loss of nationality by the child fails to meet his or her best interests because of the consequences of that loss from an EU law perspective.28 The judgment of the Court differed on a number of points from the Opinion of Advocate General (AG) Mengozzi. Whereas the CJEU held that an individual examination of proportionality under EU law is necessary in cases of automatic loss of nationality, AG Mengozzi felt that loss of nationality pursuant to a provision like Article 15(1)(c) of the Law on Nationality does not require an assessment of the consequences of such loss in concreto.29 According to the AG, such an individual assessment of proportionality would ‘encroach too far on the competence of the Member States to lay down the conditions for loss of nationality.’30 Yet, with regard to minors, the AG held that loss of nationality for children by virtue of loss of nationality of their parent(s) based on Article 15(1)(c) of the Law on Nationality was disproportionate in view of the aim of securing unity of nationality within the family and taking into account the best interests of the child.31 In comparison to the Court, AG Mengozzi thus seemed to be more careful not to interfere too much in nationality matters, which are often still considered to be at the heart of the national sovereignty of states,32 whilst at the same time prioritizing the best interests of the child. 5 Reflections on the Concepts of Nationality and EU Citizenship in ­Tjebbes In Tjebbes, the CJEU gives us an insight in the concept of nationality and how loss of nationality should be considered in light of EU law and EU citizenship. Often, nationality is defined as ‘a legal bond having as its basis a social fact of attachment, a genuine connection of existence, interests and sentiments, together with the existence of reciprocal rights and duties.’33 As we saw, the Court held in Tjebbes that it is legitimate 22 23 24 25 27 28 29 30 31 32 33 Tjebbes (n 1) paras 35–39. ibid, paras 40–41. ibid, para 44. ibid, para 45. See also Art 7 & 24(2) of the EU Charter of Fundamental Rights. ibid, para 35. ibid, para 47. Opinion of AG Mengozzi (n 4) paras 117–118. ibid, paras 114. ibid, paras 128–149. See also S Coutts, ‘Bold and Thoughtful: The Court of Justice intervenes in Nationality Law – Case C-221/17 Tjebbes’ (European Law Blog, 25 March 2019) <https://europeanlawblog.eu/2019/03/25/bold-and-thoughtful-the-court-of-justice-intervenes-in-nationality-law-case-c-221-17-tjebbes/> accessed 16 April 2019. Nottebohm Case (Liechtenstein v Guatemala) (Second Phase) [1955] ICJ Rep 1955 General List No 18.