Belligerency

sovereign state which officially declares itself to be neutral towards the belligerents in a war

thumb|Armed transport in Taliban-controlled Kabul, August 2021|302x302px

A non-belligerent is a person, a state, or other organization that does not fight in a given conflict. The term is often used to describe a country that does not take part militarily in a war.

Co-belligerence is the waging of a war in cooperation against a common enemy with or without a military alliance. Generally, the term is used for cases where no formal treaty of alliance exists. Likewise, allies may not become co-belligerents in a war if a casus foederis invoking the alliance has not arisen. Co-belligerents are defined in the Encyclopaedic Dictionary of International Law as "states engaged in a conflict with a common enemy, whether in alliance with each other or not".