Authoritative citizenship withdrawal and foreign fighters issue

Dario Chiari, LLM (King’s College London); LLB (University of Bologna)

This post tries to show the evolution of the relationship between the concepts of “national” and “Union” citizenship in light of certain judgements of the Court of Justice of the European Union (hereinafter CJEU or the Court). Using principles extrapolated from these rulings, this blog post will examine how certain CJEU principles can help deal with contemporaneous issues, like the question of citizens fighting for foreign terrorist organizations (e.g. the foreign fighters). In the last few years Europe has witnessed the rise of the phenomenon of nationals of Member States (hereinafter MSs) who decide to leave to join international terrorist organizations. The reaction of the States has been uneven, and some have proposed and implemented as a solution, the withdrawal of the citizenship.[1] Have the MSs a limitless power to withdraw citizenship? And if not, to which kind of criteria are they bound?

Notwithstanding the literal meaning of Article 20 of the Treaty on the Functioning of European Union, Member States are no longer completely autonomous to decide under which conditions it is possible to acquire and lose national citizenship and in consequence the citizenship of the Union. Even before the concept of Union citizenship was introduced with the Maastricht Treaty, the CJEU had undermined the absolute freedom of the MSs to determine at which conditions it was possible to acquire or lose national citizenship in the Micheletti case. Although the Micheletti case doesn’t represent a precedent in the issue of acquisition and loss of the citizenship, it clearly states that: “it is for each Member State, having due regard to Community law, to lay down the conditions for the acquisition and loss of nationality[2].

Furthermore, the strong link between national and Union citizenship has proven to be a double-edged sword for MSs. Indeed, if the acquisition or loss of Union citizenship is predicated upon national citizenship, then the issue of acquiring or losing national citizenship falls within the scope of European Union law. The CJEU has affirmed several times that: “the fact that a matter falls within the competence of the Member States does not alter the fact that, in situations covered by European Union law, the national rules concerned must have due regard to the latter[3].

The Rottmann case was the first opportunity for the CJEU to carry on the process of empowering Union citizen through its link to national citizenship. Janko Rottmann was an Austrian citizen before acquiring German nationality in order to avoid a national warrant for his arrest issued by the Austrian authority about serious fraud. During the naturalisation procedure he omitted to mention the proceeding against him in Austria. He obtained German nationality and lost the Austrian one. Only after the conclusion of the naturalisation procedure was the German authority informed of the warrant for his arrest. Consequently the German authority withdrew the new nationality as obtained by deception, leaving Mr. Rottmann stateless. Mr. Rottmann decided to appeal the decision, which arrived before the Federal Administrative Court where the case was referred to the ECJ for a preliminary ruling. The decision of the CJEU was cautious and the reasons for its prudence can be easily understood. First, the Court had to manage the thorny issue of citizenship. Citizenship represents a link, which ties the individual to the state and is often associated with the concept of nationality. Second, the Treaties clearly establish the supremacy of national citizenship over Union citizenship.[4] Third, all the relevant international agreements related to the reduction of statelessness allow citizenship withdrawal, even if this leads to statelessness, when it is acquired by fraud[5]and, almost all MSs are aware of this.[6] It would not have been possible, and probably even correct, to invert the role of the Union and national citizenship.

Despite its caution, the CJEU still ruled that MS national laws on citizenship must respect the principles of EU law. From Rottmann onwards MSs have the duty to set out their laws using both EU law and the principle of proportionality expressed by the Court as a reference point.[7]

The proportionality test is not conducted by the CJEU, which prefers to leave it to national judge but it did prescribe some criteria to be taken into account:

  • The consequences that the decision entails for the person concerned;
  • The consequences that the withdrawal entails for his or her family, with regard of the loss the rights enjoyed thanks to the Union citizenship, in particular in relation to minors;
  • The gravity of the offence committed by the person;
  • The lapse of time between the naturalization decision and the withdrawal decision:
  • The possibility for the person to recover his original nationality;

Although it was not mentioned on the above list, another parameter has to be taken into consideration: the fact that the fraud committed must have been decisive for the acquisition of nationality. In other words deprivation of nationality is not permissible if the naturalization would have been granted if the fraud had not occurred.[8] The importance of this standard is shown in national legislations; this provision exists in the legal order of twenty-six MSs.[9]

The fact that subsequently the German Constitutional Court decided to withdraw Mr Rottmann’s citizenship does not undermine the importance of the judgement.[10] Indeed a different personal situation or the presence of further elements missing in the Rottmann case (e.g. the presence of children, a longer period passed after the naturalization or a less serious offence) could have led to a different solution.

These elements will need to be taken into account by the national administrations at the time of decisions regarding citizenship withdrawal of so-called foreign fighters. In spite of the current political and media interest in the phenomenon, when it comes to administrative decisions it will be necessary to apply the law in a fair way and within the rule of law. Only under national legislation will it be possible to withdraw citizenship of these persons; and this national legislation has to respect European Union, Constitutional and international principles. Currently, national legislations deal with citizenship withdrawal for seriously prejudicial behaviour toward the State in a non-homogeneous and sometimes unclear way.[11] Citizenship withdrawal for seriously prejudicial behaviour exists in only fourteen MSs and in only three of them it is possible to withdraw citizenship even if it leads to statelessness.[12] Finally, in four MSs it is unclear whether protection against statelessness exists for this ground of loss of citizenship.[13]

It is interesting to note that in no MSs is it possible to withdraw citizenship acquired at birth instead of by naturalization (although some legislation is not completely clear).[14] This creates a problem in regard to the principle of equality, since there is discrimination between citizens by birth and citizen by naturalization regarding the protection of one of the fundamental human rights: the right to nationality. [15] In respect of the foreign fighter’s problem, it must be borne in mind that often these individuals are citizens of the MSs by birth, as second or third generation migrants.[16] At present, the decision by a national administrative authority to withdraw citizenship would conflict with the rule of law, inasmuch as it is not sanctioned by the legal order.

In conclusion although the foreign fighter’s problem has become an inflammatory issue in politics and the media, governments should take care to remember international and EU law principles when implementing or altering citizenship withdrawal provisions. Loss of citizenship should never cause statelessness[17] and it should never occur automatically but always be on the basis of an explicit decision of the competent authorities. This decision, again due to the principle of proportionality, should be based on offences assessed preferably by a criminal court. Against this decision, judicial review has to be granted. Finally they should take into account the consequences that the withdrawal entails for other individuals, with regard of the loss of the rights enjoyed thanks to the Union citizenship, in particular in relation to minors.


















[2] Case C-369/90 Micheletti and Others [1992] ECR I-4239

[3] Case C-274/96 Bickel and Franz [1998] ECR I-7637, paragraph 17;

Case C-148/02 Garcia Avello [2003] ECR I-11613, paragraph 25;

Case C-403/03 Schempp [2005] ECR I-6421, paragraph 19;

Case C-145/04 Spain v United Kingdom [2006] ECR I-7917, paragraph 78;

Case C-135/08  Janko Rottmann v. Freistaat Bayern [2008] accessible at, paragraph 41;

[4] Treaty on European Union, Article 9; Treaty on the Functioning of European Union, Article 20;

[5] Convention on the Reduction of Statelessness, Article 8 par.2 lit. b; European Convention on Nationality, Article 7 par.1 lit. b;

[6] Cf. European Union Democracy Observatory on Citizenship Database, accessible at, hereinafter EUDO Database;

[7] Case C-135/08  Janko Rottmann v. Freistaat Bayern [2008] accessible at, paragraph 56;

[8] See on the loss provisions of the 1961 Convention the Summary Conclusions of the expert meeting convened by the UNHCR in Tunis in 2013 paragraph 58, available on;

[9] Only Romania and Slovakia do not provide it, cf. EUDO Database;

[10] Decision of the German Constitutional Court: Bundesverwaltungsgericht, Beschluss vom 18/02/2008 (5 C 13.07), Zeitschrift für Ausländerrecht und Ausländerpolitik 2008 p.195-196;

[11] Cf. De Groot G., M.P. Vink, A Comparative Analysis of Regulations on Involuntary Loss of Nationality in the European Union, (2014), CEPS Publication No. 75, p. 26 and 27;

[12] Cf. EUDO Database;

[13] The four MSs are: Austria, Belgium, Estonia and Malta; See De Groot G., M.P. Vink, A Comparative Analysis of Regulations on Involuntary Loss of Nationality in the European Union, (2014), CEPS Publication No. 75;

[14] Cf. EUDO Database;

[15] Cf. The Universal Declaration of Human Rights, Article 15 par.1;

[16] Cf. Malet D., Foreign Fighters: Transnational Identity in Civil Conflicts, (Oxford University Press, 2013) p. 212;

[17] Convention on the Reduction of Statelessness, Article 8 par. 1; European Convention on Nationality, Article 4 par.1 lit. b