WE don't choose. Most humans do not want war most of the time.
However, individuals who are addicted to power choose to order young men to war and those young men are often more afraid of their fate as a conscientious objector whereby they may be perceived by others as a traitor than they are of their fate as soldiers.
This describes the past century or so. However, there are times when people do choose to go to war. Usually this is after the last generation of people that saw the last fourth turning crisis are dead or close to it. They perceive the injuries or humiliation sustained from their enemies as to be too great to bare. To them, the only answer is total war and the hope that they will annihilate their enemy.
We are a decentralized species because we are all individuals who make our own choices. But we tend to centralize and then decentralize regularly over time. Centralization leads to higher survival rates or at least it has in the past. Otherwise you can't defend yourself easily.
There will always be disagreements between individuals and groups. And every so often the differences will be so great that even without a draft some percentage of people will want revenge in the form of war. It is a part of humanity that will never go away. And most likely this is the case for all other decentralized intelligent species. If you're not a hive mind and have individual autonomy, war will always be a part of your species.
You can try hard to change reality, but you cannot stop everything you dislike.
"You have power over your mind - not outside events. Realize this, and you will find strength." -
Marcus Aurelius
