Constitutional Court of Belgium (Cour Constitutionnelle), No. 85/2009, 14 May 2009

Citizenship revocation on national security grounds. Terrorist crimes. Applicability only to naturalized Belgian citizens. No violation of the prohibition of discrimination. 

Art. 10 Belgian Constitution
Art. 11 Belgian Constitution
Belgian Nationality Code

The fact that revocation of citizenship (among others) on national security grounds can be applied only to naturalized Belgian citizens does not violate the principle of equality and non-discrimination (arts. 10 and 11 Belgian Const.). As a matter of fact, differences do exist between birthright and naturalized citizenship. On the one hand, citizens by birth were born with their status, without any need for a request on their part. On the other hand, naturalized citizens only acquired citizenship after a certain amount of time and provided that they satisfied certain requirements. This implies that, if these requirements cease to exist, citizenship can be revoked. Committing a serious crime, as terrorist ones are, definitely breaches the link between the state and the individual.