enemy nation; hostile country
Refers to a nation that is in a state of conflict or opposition with another, often used in political or military contexts.
その国は長年、隣国を敵対国と見なしてきた。
That country has long regarded its neighbor as an enemy nation.
Compound of 敵対 (てきたい, 'hostility, antagonism') and 国 (こく, 'country').