Freedom of States to Regulate Nationality: European Versus International Court of Justice?

Abstract

States’ freedom to regulate nationality is still a well-established principle in international customary law, the only exceptions having been introduced by some provisions in human rights treaties or in treaties on protection against statelessness. As this article illustrates, the principle of effective nationality maintains a certain role in the diplomatic protection of individuals with double or multiple nationalities, in spite of the fact that its scope has been curtailed by the Draft articles on Diplomatic Protection laid down by the International Law Commission of the United Nations. Hence, on the one hand, the ICJ’s dictum in the renowned Nottebohm judgment, concerning the requirement of a genuine link between an individual and a State of which the individual is exclusively a national, remained isolated in the following international practice. On the other hand, the ICJ’s ruling on States’ autonomy in the matter of nationality stands almost unchanged. Quite interestingly, the approach adopted by the ECJ appears to be substantially different. In fact, this Court has constantly refused to apply the principle of effective nationality when facing positive conflicts of nationalities. Moreover, in the recent Rottmann Case the ECJ carried out its controlling function and imposed precise limitations in this matter which belongs to the internal competence of the Member States, not only from the standpoint of international law, but also from the standpoint of the EU legal order.

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1 The Nottebohm Judgment of the International Court of Justice

(…) international law leaves to each State to lay down the rules governing the grant of its own nationality (…) a State cannot claim that the rules it has thus laid down are entitled to recognition by another State unless it has acted in conformity with this general aim of making the legal bond of nationality accord with the individual’s genuine connection with the State.

These dicta were rendered by the International Court of Justice (ICJ) in its famous 1955 judgment in the Nottebohm case (second phase) (hereinafter Nottebohm judgment).¹ In these dicta, the ICJ primarily reaffirmed the discretion of States to prescribe the conditions for granting their nationality. However, in the same dicta the Court also emphasized the relevance of international law in this matter when other States are involved, especially in the field of diplomatic protection.

Almost 60 years have gone by from when this judgment was rendered. Leaving aside the inquiry into the current role of nationality in the field of diplomatic protection,² it may be wondered whether nationality is still part of domestic jurisdiction, and which is the role of the principle of effective nationality.

As for the latter issue, it must be borne in mind that the prerequisite for a genuine link between an individual and a State of which the individual is exclusively a national, as required in the Nottebohm judgment, has been strongly criticized in the literature and by subsequent judicial practice.³ Pursuant to the prevailing opinion, in the Nottebohm judgment the Court was influenced by the factual context of the situation, given that Liechtenstein granted its nationality mala fide. In fact, the Court pointed out, on the one hand, Nottebohm’s “extremely tenuous” connections with the Principality and, on the other, “the existence of a long-standing and close connection between him and Guatemala”.

The peculiar nature of this part of the decision has recently been confirmed by the commentary to Article 4 of the Draft Articles on Diplomatic Protection, laid down by the International Law Commission of the United Nations.⁴

Article 4 does not require a State to prove an effective link with its national as an additional factor for the exercise of diplomatic protection, when a national possesses one nationality only.⁵

In any event, the issue of a necessary genuine link has been addressed also with reference to nationality of corporations⁶ and of ships, albeit in different terms and sometimes with different solutions. As for ships, the interpretation of the necessary genuine link rendered in the judgment of the International Tribunal on the Law of the Sea in the Saiga (no. 2) case⁷ remains of paramount importance. As is well known, Tullio Treves relied upon his scholarship and the experience he has gained within the Third United Nations Conference on the Law of the Sea in the laying down of this judgment, as well as of subsequent decisions.⁸ These pages are dedicated to him, with consideration and affection.

In spite of the foregoing, the principle of effective (or active) nationality has been evoked by judicial and arbitral courts in situations of the double or plural nationality of individuals, mainly for the aim of determining which State is entitled to the exercise of diplomatic protection against a third State.⁹ The Draft Articles on Diplomatic Protection do not require such a prerequisite (see esp. Article 6).¹⁰ On the contrary, recalling recent (although largely contested) case law, Article 7 of the Draft Articles allows the State of “predominant” nationality to bring a claim against a State of which the injured person is also a national.¹¹

In any event, the principle of active nationality—which is often described in terms of the “most real connection”—occupies a strong position in the field of the Private International Law of several States, especially with reference to the application of national law to nationals of two or more States. It is true, however, that the lex fori is sometimes held to prevail when the forum State’s nationality concurs with the nationality of another State.¹²

2 The State’s Freedom to Regulate Nationality in the International Practice

The principle of effective nationality does not entail, per se, a real limitation on the sovereign prerogative of each State in determining, according to its municipal law, who its nationals are. It is well known that the principle of the “reserved domain” of States in that matter (i.e. States’ freedom to regulate nationality) was assessed by the Permanent Court of International Justice in 1923 (albeit with some inherent limits).¹³ The absolute character of the principle of “reserved domain” was immediately trimmed down by the 1930 Hague Convention on Nationality.¹⁴ After having reassessed the freedom of each State in this matter, Article 1 of this Convention prescribes, in fact, that the law of the State “shall be recognised by other States in so far as it is consistent with international conventions, international custom, and the principles of law generally recognised with regard to nationality”.¹⁵ The peculiar wording of this provision has been mirrored in Article 4 of the Draft Articles on Diplomatic Protection.¹⁶

Particular attention should be devoted to the substantially identical provision in Article 3 of the European Convention on Nationality (Strasbourg, 6 November 1997).¹⁷ This Convention, just like the 1930 Hague Convention, aims explicitly at codifying the international law rules on the nationality of individuals, in spite of its regional level and of its few ratifications.¹⁸ Regardless of the few ratifications, many domestic laws on nationality, as is the case with the Italian law, comply per se with what is prescribed in the European Convention on Nationality.¹⁹

In light of the foregoing, it is necessary to verify whether rules of international customary law actually impose limitations on the discretion of States concerning the acquisition, retention, loss, and recovery of their nationality.

It is not a matter of drawing a distinction between the validity of a conferment of nationality on the level of domestic law and its opposability at the international level, especially in the field of diplomatic protection.²⁰ It is, rather, a matter of inquiring into the possible existence of rules of international customary law, and of inquiring whether these rules are capable of imposing general limitations on States, and have an impact on States’ discretion, even when the granting or withdrawal of nationality by the former State is not being challenged by another State.

Such an ascertainment is not easy, due to the persistent reluctance of States toward a common opinio iuris ac necessitatis in these matters. Such an approach may, on the other hand, be justified because “every State must consist of a collection of individual human beings” determined by the State itself.²¹ On the other hand, the European Convention on Nationality could not but respect the different choices of States in granting their nationality, for instance, by birth or by descent; a flexible regulation has been provided by the European Convention on Nationality also with reference to the acquisition of nationality by naturalisation.²² In fact, the existence of an international customary principle concerning States’ freedom in these matters has been recently reasserted.²³

Vice versa, possible limitations to States’ freedom in granting their nationality may be found in the international rules on the protection of human rights. Such rules may become relevant from two standpoints: the right to have a nationality, and the prohibition against discriminate. As for the former right, the scope of Article 15 of the Universal Declaration of Human Rights (Paris, 10 December 1948), that provides the right of everyone to have a nationality (para 1), together with the prohibition on States arbitrarily depriving individuals of their nationality and denying them the right to change their nationality (para 2), has been downsized by Article 24.3 of the International Covenant on Civil and Political Rights (New York, 16 December 1966).²⁴ Article 24.3 simply provides the right for every “child” to acquire a nationality; this right was subsequently reaffirmed at Article 7 of the United Nations Convention on the Rights of the Child (New York, 20 November 1989).²⁵

The impact of Article 20 of the American Convention on Human Rights (San José, Costa Rica, 22 November 1969)²⁶—that recaptures and extends the provision of Article 15 of the Universal Declaration—is much stronger.²⁷ Starting from an advisory opinion delivered in 1984, the Inter-American Court of Human Rights has often grounded its decisions based upon Article 20 of the American Convention on Human Rights; the Court, in fact, proclaimed that the right to nationality is an “inherent human right recognised in international law”.²⁸ As for the [European] Convention for the Protection of Human Rights and Fundamental Freedoms (Rome, 4 November 1950; hereinafter ECHR),²⁹ it is not intended to apply to issues of nationality.³⁰ Accordingly, the European Court of Human Rights refrains from examining claims or those parts of claims that address questions of the nationality of individuals.³¹

The existence of an international customary right to nationality could, rather, be inferred from the multilateral conventions on statelessness, and especially from the Convention on the Reduction of Statelessness (New York, 30 August 1961; hereinafter 1961 Convention).³² This Convention contains many provisions which seek to prevent statelessness, and it is considered as an instrument which implements the customary international rule on the obligation to avoid statelessness.³³ Although the domestic laws on nationality of many States follow such a regulation, several of those same States (such as Italy) did not yet ratify the 1961 Convention.³⁴ It is, nevertheless, also worth mentioning that a large number of States have ratified the Convention in the past 5 years.

The European Convention on Nationality provides a general safeguard against statelessness, not only with reference to acquisition but especially with reference to the loss of nationality ex lege or at the initiative of a State Party or the individual. Article 7, which was moulded on the 1961 Convention, aims at the prevention of an arbitrary deprivation of nationality, and it provides for as many as seven cases of legitimate withdrawal. Both Article 7.3 and Article 8.1 (concerning the voluntary renunciation to nationality) provide that the persons concerned do not thereby become stateless, with one main exception that will be addressed later in this chapter.³⁵

It seems to be somewhat easier to demonstrate the existence of a rule of international customary law that proscribes any discrimination in the regulation of modes of the acquisition, loss and recovery of nationality. The limitation on the freedom of States in this case is, in fact, supported by several international treaties other than those addressing the protection of human rights. Concerning this aim, the United Nations Convention on the Nationality of Married Women (New York, 20 February 1957),³⁶ where for the first time the incidence of the husband’s status civitatis on the wife’s nationality was proscribed, must be borne in mind.³⁷ This Convention’s inspiring principle was later transposed in Article 9 of the United Nations Convention on the Elimination of All Forms of Discrimination against Women (New York, 18 December 1979).³⁸

Nonetheless, the prohibition against discrimination based on nationality has acquired a broader scope compared to the prohibition based on gender. A general “right to nationality” is in fact laid down in Article 5.d.iii of the International Convention on the Elimination of All Forms of Racial Discrimination (New York, 7 March 1966).³⁹

On the one hand, Article 5.1 of the 1997 European Convention on Nationality, that expressly proscribes discrimination in the field of nationality on the grounds of sex, religion, race, colour or national or ethnic origin, appears to have been drafted in a certainly more detailed fashion. On the other hand, Article 5.2 shows a more flexible nature where it simply provides that each State “shall be guided” by the principle of non-discrimination between its nationals, whether they are nationals by birth or have subsequently acquired its nationality. The wording of Article 5.2 shows a simple declaration of intent as opposed to a mandatory rule to be followed in all cases. In this case, too, exceptions are allowed.⁴⁰

Both these exceptions and the effort expended by the drafters of the Convention in listing examples of legitimate “distinctions”⁴¹ also show how strong the sovereign prerogatives of the States still are in this matter.

3 The ECJ Facing the Positive Conflicts of Nationalities

As we will see,⁴² in the European Union, too, Member States assert their own exclusive competence in regulating nationality. Such an autonomy has been repeatedly acknowledged by the European Union Court of Justice (ECJ).⁴³

It is needless to underline here the peculiar nature of EU Law compared to that of other international organizations, especially with regard to the wide range of “freedoms” that EU Law guarantees to Member State citizens, as well as with regard to the “judicial activism” of the ECJ.⁴⁴ Suffice it to recall here that the sources of EU Law can be traced back to a series of international treaties and that EU Law has multiple interactions with international law.⁴⁵

As for the criterion of effective nationality, the ECJ case law moves totally away from the case law of international courts. Unlike The Hague Court, the Luxembourg Court has tackled several “preliminary rulings” on the application of EU Law to individuals with two nationalities.

When facing positive conflicts of nationalities, the ECJ constantly refuses to apply the principle of effective nationality, although it is aware that this principle prevails both in international law and in the private international law of its Member States. Even back in the 1980s, when addressing claims for the payment of expatriation allowances filed by officials of the European Communities, the Court held that the concept of effective nationality, “mainly used in private international law”, cannot be transferred to a quite different sphere, such as the Staff Regulations, for these officials.⁴⁶ Rather surprisingly, though, the same negative judgment was rendered 30 years afterwards in the field of private international law. In the Hadadi judgment, the Court in fact underlined “the imprecise nature” of the concept of effective nationality, due to which “a whole set of factors would have to be taken into consideration, not always leading to a clear result”.⁴⁷ As for the field of international law, Advocate General Tesauro, in the Micheletti case, has strongly pointed out that the origin of the problems relating to effective nationality lies in “a romantic period” of international relations and, in particular, in the concept of diplomatic protection.⁴⁸

Nonetheless, if we consider the peculiar nature of primary and secondary EU Law, these rulings are substantially irrefutable. Leaving aside the specific rulings concerning the officials of the European Communities, it appears clear that the intent of the ECJ is to privilege, concerning individual nationals of both a Member State and a non-member country, the status civitatis of the former State. Such a status is in fact apt to ensure the different freedoms granted by the Treaty even in those cases where the status does not overlap with the effective nationality. The leading case in this matter is still the ECJ judgment in Micheletti, concerning the right of establishment (now Article 49 Consolidated Version of the Treaty on the Functioning of the European Union, 9 May 2008, entered into force the 1 December 2009; hereinafter TFEU) denied by the Spanish authorities to an Italian national iure sanguinis on the ground that this person also held the nationality of Argentina iure soli and was last resident in this non-member country. In the opinion of the Luxembourg judges, it is not permissible to interpret EC Law to the effect that, where a national of a Member State is also national of a non-member country, the other Member States may make the recognition of the status of the Community national subject to an additional condition.⁴⁹ A similar reasoning was given by the Court in the Saldanha judgment on the obligation of lodging a cautio iudicatum solvi imposed by the Austrian authorities on a national of both the United States of America and the United Kingdom, living in Florida.⁵⁰

Moreover, the Court cannot avoid extending its preference for the “more favourable” nationality also in favour of nationals of both Member States, e.g. with regard to the right to establishment and the freedom of movement for workers.⁵¹

Still with reference to the possession of the dual nationality of Member States, in the well-known case of Garcia Avello ⁵² the ECJ refused to evoke both the principle of effective nationality and the opposite principle of the prevalence of the nationality of the forum. The utilization of one or the other principle would in any case have led to the application of the Belgian rules on the surnames to two children having both Spanish and Belgian nationalities but residing in Belgium since their birth. The Court seemed to be aware of the provisions imposed by international law, and notably by Article 3 of the 1930 Hague Convention, under which a person having two or more nationalities may be regarded as a national by each of the States whose nationality he possesses. Nevertheless, in the ECJ’s opinion, this rule does not impose an obligation, and rather simply provides an option for the Contracting Parties to give priority to the forum’s nationality.⁵³ As usual, the Court seemed to favour the nationality that ensures the freedoms granted by the Treaty. In fact, the enjoyment of the right to bear only the surname which results from the application of the legislation of Spain—whose legislation was the first to determine the children’s surname—avoids “serious inconvenience for those concerned at both professional and private levels” in the future.⁵⁴

On the contrary, the ECJ tends to refrain from giving any indications as to the relevant nationality when it considers that the legal situation brought to its attention does not affect any fundamental freedoms of movement under the Treaty⁵⁵; or again, as in McCarthy judgment, when the Court notices that the situation of a person “has no factor linking it with any of the other situations governed by European law and the situation is confined in all relevant respects within a single Member State”.⁵⁶

4 The State’s Freedom to Regulate Nationality in EU Law

The Garcia Avello judgment is grounded either on the prohibition of any discrimination on the ground of nationality (now Article 18 TFEU) or on the enjoyment of the status of Union citizen (now Article 20 TFEU) which is “destined to be the fundamental status of nationals of the Member States”.⁵⁷ In the past, the ECJ had already characterized in the same manner the situation of some European citizens with the aim of acknowledging some of their liberties granted by EC Law, such as the right of free movement and residence within the territory of the Member States.⁵⁸ The same reference to this fundamental status, in support of the same liberties, was confirmed in the subsequent Zhu and Chen case.⁵⁹

Nonetheless, in the recent Ruiz Zambrano case, the Luxembourg judges have reached the point of granting a primary and exclusive role to European citizenship.⁶⁰ In this decision, the ECJ only recalled the basic rule that grounds such status (Article 20 TFEU), with the aim of imposing on a Member State the obligation of granting the right of residence to a third-country national with minor EU citizens children who are dependant upon him, i.e. the obligation to grant him the right of residence within the territory of the Member State of residence and of nationality iure soli of his children. In the Court’s opinion, Article 20 TFEU precludes national measures which have the effect of depriving citizens of the Union of “the genuine enjoyment of the substance of the rights conferred by virtue of their status” as citizens of the Union.⁶¹

Although two subsequent judgments have narrowed the extent of this ruling,⁶² it remains evident that European citizenship is now capable of a much broader scope compared to the one established by the Treaty on European Union (Maastricht, 7 February 1992; hereinafter TEU).⁶³ Here, we cannot spend time on the extra rights granted to nationals of Member States compared to the rights that those same States grant to their own nationals,⁶⁴ nor on the nature of this nationality defined as a “miracle” in light of its peculiar effects.⁶⁵

It is however important to recall that, regardless of the amendments (at times considered as symbolic) introduced by the Lisbon Treaty,⁶⁶ “every national of a Member State” is considered as a citizen of the Union, and that the citizenship of the Union shall “not replace national citizenship”.⁶⁷ Accordingly, the autonomy of the Member States in the matter of nationality seems to be intact.

Moreover, Declaration No. 2 on nationality of a Member State, annexed by the Member States to the final act of the Maastricht Treaty on European Union, and the decision of the Heads of State and Government, meeting within the European Council at Edinburgh on 11 and 12 December 1992, concerning the definition of the scope ratione personae of the provisions of European Union Law referring to the concept of a national, remain in force. More recently, as stated in Article 7.1 of Directive 2004/38/EC on the right of the citizens of the Union and their family members to move and reside freely within the territory of Member States, “Union citizen” means any person having the nationality of a Member State.⁶⁸

Due to the Member States’ persistent autonomy in regulating their nationalities, the recommendations of the European Parliament inviting Member States to adopt uniform rules on the attribution of nationality to the nationals of non-member countries resident in the Member States, have gone unheeded.⁶⁹

As for the Micheletti judgment, the ECJ has constantly reaffirmed that “under international law, it is for each State Member to lay down the conditions for the acquisition and loss of nationality”⁷⁰; such dictum makes use of the same wording used in the ICJ’s reasoning in the Nottebohm judgment.⁷¹ Nevertheless, the dictum extends the ICJ’s reasoning by adding a reference to the withdrawal of nationality.

To this extent, the ECJ has respected this principle; the Luxembourg judges have in fact stringently applied the Member States’ provisions on nationality for determining the scope of the EC Treaty ratione personae. In the Kaur case, the ECJ accurately followed the indications provided in the 1972 and 1982 Declarations by the Government of the United Kingdom on the definition of the term nationals. As a result, the right to enter or remain in the territory of this State has been denied to a citizen of the United Kingdom and Colonies who had become a British Overseas Citizen under the terms of the British Nationality Act 1981.⁷²

The national rules on nationality have also been rigidly applied in situations where they produced the acquisition of nationality iure soli, thus potentially resulting in being unwelcome in other Member States or in the same Member State that had adopted them. As for the former case, in the Zhu and Chen the United Kingdom claimed that Mrs. Chen’s move from the UK to Northern Ireland, with the aim of having her child acquire iure soli the nationality of another Member State, constitutes an attempt to improperly exploit the provisions of Community law.⁷³

As for the latter case, in the Ruiz Zambrano ⁷⁴ the Belgian government claimed that Mr. Ruiz Zambrano could not rely on the Belgian Law on nationality because he had disregarded the laws of his country. Mr. Ruiz Zambrano (a Colombian national to whom Belgian authorities refused asylum) had not in fact registered his child with the diplomatic or consular authorities, and he had rather followed the procedures available to him for acquiring Belgian nationality iure soli for his child and then tried, on that basis, to legalise his own residence. It does not come as a surprise that both the Irish and the Belgian law on nationality have been subsequently amended.⁷⁵ In the Eman and Sevinger case, the ECJ also considered the Dutch rules on nationality to prevail over the will of the Dutch government to exclude from elections for members of the European Parliament Dutch nationals resident in overseas countries and territories as referred to in Article 299.3 EC.⁷⁶

Finally, it is worth pointing out that Member States almost always agree on the unilateral nature either of these rules or of these Declarations both when these rules are drafted by other States and when governments partake in the proceedings of preliminary rulings.⁷⁷ Consequently, the disapproval expressed by the Italian government towards the government of Romania, concerning the provisions that made it possible for several former nationals of Moldavia and other adjoining States to recover their Romanian nationality, comes as an exception to the general acknowledgement of the other Member States’ sovereignty in this matter.⁷⁸ Such an approach mirrors the Member States’ concern to limit the number of individuals who, by unexpectedly acquiring a Member State’s nationality and consequently EU nationality, are granted the right of free movement and residence within the territory of the European Union, and as such within the territories of single Member States.

5 The Rottmann Judgment of the ECJ

The dictum concerning the exclusive competence of the Member States in regulating their nationalities, as asserted by the ECJ on several occasions starting with the Micheletti judgment, is however always stated together with the proviso “having due regard to Community law”.⁷⁹ The sense of this proviso was originally considered as obscure or concerning respect for the individual’s fundamental rights, which had become part of the principles of EU Law under Article 6 of the TEU.⁸⁰

If the truth were to be told, the Court had only once previously scrutinized and set aside the application of some norms on the nationality of a Member state, and notably the Italian provisions (now repealed) that attributed ipso iure to a foreign woman this status civitatis by virtue of her marriage, making it impossible for the woman to renounce such a status. In the judges’ opinion, the EC rules concerning the payment of expatriation allowances to officials of the European Communities must be interpreted in such a way as to avoid any unwarranted difference of treatment between male and female officials who are, in fact, placed in comparable situations.⁸¹ Even though the ECJ had implicitly given a negative appraisal of the Italian provisions, it must be pointed out that the Court was nevertheless addressing a case of dual nationality, i.e. a case regarding the choice between a person’s two status civitatis.⁸²

On the other hand, the status of EU nationals has, over time, acquired a scope and a role which are progressively more relevant to the point of being qualified as a “fundamental status”. In the light of the Member States’ approach to this matter, it was not easy to foresee control by the ECJ on the requisites to this status, i.e. on the manner of acquisition and withdrawal of their nationalities.

Nonetheless, the judicial activism of the Court reached this goal in the renowned Rottmann case.⁸³ Going beyond the self-restraint shown by the Advocate General in his detailed and at times emphatic opinion, the ECJ has brought clarity concerning the way in which Member States must have due regard, in exercising their powers within the sphere of nationality, to European Union Law.

In the case in point, Mr Rottmann, an Austrian national by birth, had acquired German nationality by naturalisation. However, the authorities of the Land of Bavaria decided to withdraw this naturalisation with retroactive effect on the ground that it had been obtained fraudulently, since Rottmann had not disclosed the fact that he was the subject of a judicial investigation in Austria.

According to Austrian law, Rottmann’s naturalisation in Germany had the effect of losing his Austrian nationality, without the withdrawal of his naturalisation in Germany implying that he automatically recovered his nationality of origin. On final appeal against the judgments issued by the Bavarian courts, the German Federal Administrative Court (Bundesverwaltungsgericht) referred some questions to the Court of Justice on the application of European Union Law. The German Court wanted in particular to ascertain whether Article 17 EC Treaty (now Article 20 TFEU) allows a decision to withdraw naturalisation, the effect of which would entail the loss of Union citizenship for the person concerned who would thereby be rendered stateless.

The ECJ first reaffirmed once again that the conditions for the acquisition and loss of nationality fall within the competence of each Member State “under international law”.⁸⁴ Moreover, the Court recalled either Declaration No. 2 on nationality of a Member State, annexed to the final act of the EU Treaty, or the decision of the Heads of State and Government, meeting within the European Council at Edinburgh on 11 and 12 December 1992.⁸⁵ Nevertheless, on such an occasion such acts are considered as simple instruments for the interpretation of the EC Treaty with no other effects.⁸⁶

The ECJ further specified peremptorily that the situation of a citizen of the Union becoming stateless as a result of the withdrawal of his nationality falls, “by reason of its nature and its consequences”, within the ambit of European Union Law.⁸⁷ In fact, the person concerned loses the status of a citizen of the Union conferred by Article 17 EC, which is “intended” (and not “destined”, as it had been in previous rulings)⁸⁸ to be the fundamental status of nationals of the Member States. Consequently, such a decision to withdraw nationality is amenable to judicial review carried out in the light of European Union Law. Under this review, it should be checked whether the decision in question is justified by a reason relating to public interest and whether it respects the principle of proportionality.⁸⁹

The Court considers that withdrawing naturalisation because of deception corresponds to a reason relating to public interest based both on the protection of the special relationship of solidarity and good faith between the Member State concerned and its nationals, and on the reciprocity of rights and duties. That decision is, moreover, in keeping with the rules of international law. The ECJ is in fact aware that Article 8.2 of the 1961 Convention on the Reduction of Statelessness provides for the deprivation of nationality if it is acquired by means of misrepresentation or by any other act of fraud. The ECJ is also aware that Article 7.1.b and 7.3 of the 1997 European Convention on Nationality does not prohibit a State Party from depriving a person of his nationality, even if he thus becomes stateless, when that nationality was acquired by means of fraudulent conduct, false information or the concealment of any relevant fact attributable to that person.⁹⁰

Once it assessed the legitimacy, in principle, of the German decision withdrawing naturalisation on account of deception, the ECJ held that it is, nevertheless, for the national court to ascertain whether the decision to withdraw nationality observes the principle of proportionality so far as concerns the consequences it entails for the person concerned in the light of European Union Law, “in addition, where appropriate, to examination of the proportionality of the decision in the light of national law”.⁹¹

Eventually, the Court (seemingly) refrained from ruling on the question concerning the recovery of nationality by Rottmann’s birth because, on the one hand, the withdrawal of naturalisation had not become definitive and, on the other, no decision concerning his status had been taken by Austria. However, the ECJ warned that the duty of the Member States to exercise those powers having due regard to European Union Law (i.e. with regard to the principle of proportionality) applies “both to the Member State of naturalisation and to the Member State of the original nationality”.⁹²

The holding in this judgment is clearly ground-breaking on a number of issues. First, the Luxembourg Court carried out its controlling function in a matter which seemingly belongs to the internal competence of the Member States, not only from the standpoint of international law, but also from the standpoint of the EU legal order. It is no coincidence that eight Member State governments, supported by the Commission, submitted observations to the Court in this case.⁹³ It also seems redundant to recall that the matter of nationality touches upon the very core of each State.

Second, the Court’s dicta addressed not only national provisions on the withdrawal of nationality, but also the provisions on the recovery of Member States’ nationality, and are as such capable of affecting the acquisition of the status civitatis. Finally, the ECJ introduced, in such a delicate matter, the principle of proportionality, and most of all it enjoined national courts to apply the rules on nationality of their States (which doubtlessly have constitutional relevance) under the EU Law criteria indicated by the Court itself.⁹⁴

As is foreseeable, this ground-breaking decision has given rise to strong doctrinal reactions in the opposite direction.;⁹⁵ Some authors have strongly criticised the Court’s invasion in a field that is still imbued with the principle of “reserved domain”;⁹⁶ others have approved the ECJ’s orientation,⁹⁷ at times sensing in the relationship between European citizenship and nationality the confirmation of a “pluralism of citizenship” or the beginning of a “relative autonomy” of European citizenship⁹⁸ or, again, an “embryon de fédéralisation du droit de la nationalité des Etats membres”.⁹⁹

Regardless of the fact that the Court’s attitude has often been considered (at times in a critical way) to be prudent,¹⁰⁰ the preoccupation with verifying the compatibility of some State provisions on nationality with the holding in the Rottmann judgment has also been raised.¹⁰¹ It seems to be too early to predict what the Member States’ reactions will be, however,¹⁰² although an increase in challenges to domestic decisions in the field of nationality can be foreseen.¹⁰³

On the other hand, it would be naïve to underestimate the peculiarity and the potential of EU Law compared to other examples of international regional cooperation. However, here we simply want to address the specific attitude of the ECJ towards some consolidated principles of international law. We have already assessed that the Luxembourg judges, unlike international courts, expressly and repeatedly avoid applying the principle of effective nationality to positive conflicts of nationality.¹⁰⁴

Moreover, comparing the ICJ’s Nottebohm judgment¹⁰⁵ with the ECJ’s Rottmann judgment, it may be stressed that, although both decisions are grounded on the international principle concerning States’ freedom to regulate nationality, the effects that these two decisions have are visibly different.

As we have pointed out, the Nottebohm judgment only states the ineffectiveness in international law—i.e., concerning diplomatic protection—of a person’s status civitatis when such a status lacks the prerequisite of effectiveness. However, this ruling remained isolated in the following international practice, both legislative and judicial. Vice versa, a careful look at the Rottmann judgment shows that the ECJ has not simply scrutinized in which manner the Member States exercise their exclusive competence in this field, but it has also enjoined precise limitations to this competence.

In fact, the Court’s invitation to national judges to ensure a higher level of guarantees for the individual can be valued when the national rules already provide for judicial control on the loss (or acquisition) of respective nationalities.¹⁰⁶ However, the ECJ seems to impose such a scrutiny also when this is not provided by the Member States’ legal order, and it seems to enjoin domestic courts to state the reacquisition of nationality when such a recovery is not provided by their laws.¹⁰⁷

This entails that the Luxembourg Court disregards the Hague Court. After all, unlike the Advocate General, in the Rottmann Judgment (as in its previous rulings) the ECJ refrained from referring to the Nottebohm judgment.¹⁰⁸ Hence, although the specific wording of the two Courts on a State’s sovereign prerogative to regulate nationality by respective municipal law might suggest the idea of a “cross-fertilization”, such a consonance is merely an apparition. The Rottman case might stand as an example of the “fragmentation of international law”: two perspectives the content of which has been widely analysed by my friend Tullio, with his usual lucid thoughts.¹⁰⁹