arbitrary as the impact on the individual outweighs the purpose of the measure pursued by the State.193 111. The proportionality of a measure in the national security context refers to “the assessment of the seriousness of the terrorist threat the individual or entity poses, and the purpose of the measure to curb that terrorist threat as compared to the potential direct and indirect impact the measure will have on the individual or entity and third parties involved, and the limitation of the exercise on relevant human rights .194 112. Furthermore, States must pay attention to a number of elements when applying the principle of proportionality, consequences of the deprivation for the person involved and their family members, with particular regard to whether or not they would lose their residence rights in the country where the person held nationality.195 Also, the proportionality test should be applied individually for each person affected by the deprivation of nationality and special consideration should be given to the status of children, with “best interests of the child being the guiding principle.196 113. The CJEU has considered proportionality in relation to nationality matters more elaborately in Janko Rottmann v. Freistaat Bayern. In this case, the Court confirmed that an EU principle of proportionality applies to domestic decisions of EU Member States on the withdrawal of nationality. It explained that it is “for the national court to ascertain whether the withdrawal decision at issue in the main proceedings observes the principle of proportionality so far as concerns the consequences it entails for the situation of 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 .197 The Court continues: “[I]t is necessary […] to take into account the consequences that the decision entails for the person concerned and, if relevant, for the members of his family with regard to the loss of the rights enjoyed by every citizen of the Union. In this respect it is necessary to establish, in particular, whether that loss is justified in relation to the gravity of the offence committed by that person, to the lapse of time between the naturalisation decision and the withdrawal decision and to whether it is possible for that person to recover his original nationality.”198 114. In the case of M.G. Tjebbes and Others v Minister van Buitenlandse Zaken, the CJEU provides further guidance on the principle of proportionality, adding to the explanations in the Rottmann case. In case of loss of EU citizenship, the authorities need to carry out a full assessment based on the principle of proportionality enshrined in EU law. “That examination requires an individual assessment of the situation of the person concerned and that of his or her family in order to determine whether the consequences of losing the nationality of the Member State concerned, when it entails the loss of his or her citizenship of 193 UNHCR, ’Tunis Conclusions‘ , para . Glion Recommendations (2019), p. 9. 195 ILEC Guidelines (2015), section II.4. 196 ILEC Guidelines (2015), sections II.5 and II.6. 197 CJEU, Janko Rottmann v Freistaat Bayern (2010), Case C-135/08, para 55. 198 CJEU, Janko Rottmann v Freistaat Bayern (2010), Case C-135/08, para 56. 194 59