joint defense; collective defense
Refers to a cooperative military or security arrangement where multiple parties agree to defend each other, often used in political and military contexts.
Exercises were conducted under the Japan-U.S. joint defense treaty.
It is necessary to strengthen the framework of collective defense.
集団防衛 is often used in the context of collective self-defense under international law, while 共同防衛 emphasizes joint action by specific allies.
Compound of 共同 (きょうどう, 'joint, cooperative') and 防衛 (ぼうえい, 'defense').