return to one's homeland; repatriation
Often used in political or historical contexts, such as the return of a territory or people to their native country.
Okinawa's return to the homeland was realized in 1972.
They have long continued the movement for return to the fatherland.
帰国 is a general term for returning to one's country, while 祖国復帰 specifically emphasizes return to the fatherland, often with political or historical connotations.
Compound of 祖国 (fatherland) and 復帰 (return). The exact historical derivation is uncertain; the term gained prominence in post-war contexts.