right of belligerency
Legal term referring to the right of a state to engage in war under international law. Often discussed in the context of Japan's constitutional renunciation of war.
日本国憲法は交戦権を否認している。
The Constitution of Japan renounces the right of belligerency.
交戦 means 'hostilities' or 'engagement in battle', while 交戦権 is the legal right to engage in such hostilities.
戦争権 is a broader term for the right to wage war, but 交戦権 specifically refers to the rights and obligations of a recognized belligerent under international law.
Compound of 交戦 (kōsen, 'hostilities') + 権 (ken, 'right'). The term is a modern legal coinage used in international law and constitutional discourse.