78 QIL 60 (2019) 69-97 ZOOM IN 3. The obligation of States of nationality to repatriate the family members of FTFs Prior to delving into the question of whether the current international legal framework imposes on States of nationality an obligation to repatriate the family members of FTFs and which other relevant obligations stem from it, an important caveat is needed as arguing in favour of the adoption of proactive measures to facilitate the return of women and children is not the same thing as claiming that if they are released and somehow succeed in traveling back to their countries of origin they would have to be allowed entry. The latter scenario is rather implausible,39 but also easier to sort out.40 As is well known, under both customary international law and human rights law admission to a State primarily depends on nationality.41 The essence of nationality, which has eloquently been defined as ‘an institution of domestic law [with] consequences in international law’,42 can be said to lie in the State’s duty to admit its nationals and allow them to reside within its territory. Such a duty exists first and foremost vis-à-vis other States, meaning that it is an obligation that is needed to balance States’ sovereign prerogative to regulate the presence of foreigners on their territory.43 Under international human rights law the State’s obligation to admit its nationals is mirrored by the individual’s right to enter and reside free from expulsion in his/her country of nationality.44 Pursuant to Article 39 T Mehra and C Paulussen, ‘The Repatriation of Foreign Fighters and Their Families: Options, Obligations, Morality and Long-Term Thinking’ ICCT (6 March 2019) <https://icct.nl/publication/the-repatriation-of-foreign-fighters-and-their-families -options-obligations-morality-and-long-term-thinking/>. 40 This scenario has been already analysed, although more succinctly, elsewhere see Capone (n 1). 41 As clarified by the International Court of Justice (ICJ) nationality is determined by one’s social ties to the country of one’s nationality, and when established, gives rise to rights and duties on the part of the State, as well as on the part of the citizen/national. Nottebohm Case (Liechtenstein v Guatemala) [1955] ICJ Rep 4. 42 I Shearer, B Opeskin, ‘Nationality and Statelessness’, in B Opeskin, R Perruchoud, J Redpath-Cross (eds), Foundations of International Migration Law (CUP 2012) 93. 43 A Edwards, ‘The Meaning of Nationality in International Law in an Era of Human Rights’, in A Edwards, L van Waas (eds), Nationality and Statelessness under International Law (CUP 2014) 11; A Kesby, The Right to Have Rights Citizenship, Humanity, and International Law (OUP 2012) 16. 44 ibid 17.