War is only plasusible when multiple nations exist, and as the number of soveriegn nations reduces the dilema of world domination becomes more apparent.

And when one soverign state is so enormously mighty that they dominate all other resistance entirely then surrender is expected, and even after all the the murdering is done, and the barrels have cooled and regios have been demarkated as nuclear waste zones, and when the atomic dust has settled and the fight of all fights is over, and there is one victor, and decades pass, and bloodline mix in sexual rapture, when all this comes to pass war it's self has been killed.

And all that is left is peace.

And the new world reflects in shame on the forefathers and in disgust at the amount of effort was spent in keeping war alive, keeping war alive meant insisting on independant soveirgn identity.