Belligerent

A belligerent is an individual, group, country, or other entity that acts in a hostile manner, such as engaging in combat.

The term comes from the Latin bellum gerere ("to wage war").

[2][3]"Belligerency" is a term used in international law to indicate the status of two or more entities, generally sovereign states, being engaged in a war.

Wars are often fought with one or both parties to a conflict invoking the right to self-defence under Article 51 of the United Nations Charter[4] (as the United Kingdom did in 1982 before the start of the Falklands War[5]) or under the auspices of a United Nations Security Council resolution (such as the United Nations Security Council Resolution 678, which gave legal authority for the Gulf War).

[6] Once the status of belligerency is established between two or more states, their relations are determined and governed by the laws of war.