8 ETS 166 – European Convention on Nationality, 6.XI.1997 Chapter VII – Military obligations in cases of multiple nationality Article 21 – Fulfilment of military obligations 1 Persons possessing the nationality of two or more States Parties shall be required to fulfil their military obligations in relation to one of those States Parties only. 2 The modes of application of paragraph 1 may be determined by special agreements between any of the States Parties. 3 Except where a special agreement which has been, or may be, concluded provides otherwise, the following provisions are applicable to persons possessing the nationality of two or more States Parties: a Any such person shall be subject to military obligations in relation to the State Party in whose territory they are habitually resident. Nevertheless, they shall be free to choose, up to the age of 19 years, to submit themselves to military obligations as volunteers in relation to any other State Party of which they are also nationals for a total and effective period at least equal to that of the active military service required by the former State Party; b Persons who are habitually resident in the territory of a State Party of which they are not nationals or in that of a State which is not a State Party may choose to perform their military service in the territory of any State Party of which they are nationals; c Persons who, in accordance with the rules laid down in paragraphs a and b, shall fulfil their military obligations in relation to one State Party, as prescribed by the law of that State Party, shall be deemed to have fulfilled their military obligations in relation to any other State Party or States Parties of which they are also nationals; d Persons who, before the entry into force of this Convention between the States Parties of which they are nationals, have, in relation to one of those States Parties, fulfilled their military obligations in accordance with the law of that State Party, shall be deemed to have fulfilled the same obligations in relation to any other State Party or States Parties of which they are also nationals; e Persons who, in conformity with paragraph a, have performed their active military service in relation to one of the States Parties of which they are nationals, and subsequently transfer their habitual residence to the territory of the other State Party of which they are nationals, shall be liable to military service in the reserve only in relation to the latter State Party; f The application of this article shall not prejudice, in any respect, the nationality of the persons concerned; g In the event of mobilisation by any State Party, the obligations arising under this article shall not be binding upon that State Party. Article 22 – Exemption from military obligations or alternative civil service Except where a special agreement which has been, or may be, concluded provides otherwise, the following provisions are also applicable to persons possessing the nationality of two or more States Parties: