noun
peacekeeping operation
Refers to military or civilian operations aimed at maintaining peace, often in the context of UN peacekeeping missions.
国連の平和維持活動に参加する。
Participate in UN peacekeeping operations.
平和維持軍 refers specifically to the peacekeeping forces (troops), while 平和維持活動 covers the broader operations and activities.
Compound of 平和 (peace), 維持 (maintenance), and 活動 (activity). A calque from English 'peacekeeping operation'.