noun
choice of nationality; choice of citizenship
Legal term referring to the act of selecting one's nationality, often in the context of dual citizenship or naturalization.
日本では、二重国籍者は二十二歳までに国籍選択をしなければならない。
In Japan, dual citizens must choose their nationality by age 22.
国籍選択の手続きは、法務局で行います。
The procedure for choosing nationality is done at the Legal Affairs Bureau.
Compound of 国籍 (nationality) and 選択 (choice, selection). A straightforward modern legal term.