In my understanding war can be found both at an individual and a large scale (nations,communities,etc)
Some people tend to believe that war steps in when verbal communication has failed and the two sides resolve into violent actions to solve the problem. But what happens when one side purposely wages war only to benefit from it? When one side consciously decides to destroy the other simply because they would not tolerate the existence of them.

People generally try to avoid situations that would get them killed or have a high propability of hurting someone they care about. That comes with our genes and the survival instict. So how can you make someone do something that goes against his biological warnings? By exploiting the human cognition ofcourse. By making someone believe in the narrative of some else's POV and therefore bypassing his biological urge for survival. That is how we can see the famous verse 'In peace sons bury their fathers, in war fathers bury their sons' take place.

There have been many historical events with both of the mentioned situations. But all share the same thing: common belief in a purpose, whether that is related to personal or group benefits. The belief that we should fight with them because we are right, better, stronger etc. The last words have been the bread and butter of various famous Leaders throughout the human history. The tools that have been used to actually convince a large group of people that there can be a objective and fair comparison between them and another group of people usually resulting into the violent surpression of one from the other.

So, is war just another human invention, or we are bound to inevitable conflicts?