If war is solved by all attacked countries surrendering immediately so one aggressor rules the world, I'm sure factions would emerge within it who are competing for power again.
Maybe a solution could come from some defensive technology permanently outperforming offensive technology? I think people would still find a way and the wars might be or begin by psychologically changing people's allegiances.
We have numerous examples - Jan 6th, the Bundy standoffs, Oklahoma City, the Black Wall Street bombings - the risk isn’t zero.
Obviously civil wars happen all the time in places where there isn't a single powerful enough government to keep them suppressed.
Maybe you want one world government or a military alliance that includes every country and they all fight against any local wars no matter what. But what happens if some big enough group feels (or is) oppressed by that government and tries to fight it? Oppression by the majority forever is better than independence for anyone?
Enjoy your freedoms: paid for in blood.
Enjoy your freedoms: paid for in blood.
This is an overly broad and philosophical question. It's positioned far away. We could all get together for a cup of coffee and discuss this topic for ages.
A more grounded and practical question would be: why didn't Biden stop the war?
Now we're talking! One should expect lots of contradictory opinions, quite some hostility, a couple of MTG-like personalities with followers and of course this one specific comment downvoted to hell.
But see, that's exactly the point: opinions vastly differ on the same subject depending on whether the situation is a hypothetical one far away or a physical reality.