Abstract: Nationality is not only a most sensitive issue for States, it is also the very status underpinning Union citizenship. On the basis of this intricate relationship, the Court of Justice of the Europe Union has developed a line of reasoning that Member States are subject to the obligation to observe EU law also in nationality matters. The case of Wiener Landesregierung is not just the latest piece in this strand of cases, but also the very first instance where the Court has spelled out that the obligation to observe EU law also relates to the process of awarding nationality. In spite of the rather odd circumstances of the case, the judgment, thus, underscores the ever-growing importance of EU law in the (supposedly reserved) domain of nationality. The analysis, to this end, not only provides further insights into what the observance of EU law in this field amounts to, but also highlights that the required proportionality assessment supports an understanding of nationality as a status that hinges on a genuine link on the international plane. Despite the complicated process of internalizing the obligation to observe EU law in some Member States – and Austria in particular – EU law thereby strengthens the individual’s right to have rights. The analysis, moreover, also addresses the issue of mutual trust and the wider implications of the judgement in Wiener Landesregierung that contrast with the hitherto unwavering dictum of Micheletti that Member States must not question the nationality decisions of other Member States.
