Total War: Mandatory or Destructive

In my opinion total war was needed, because the south wouldn't surrender any other way. This is because if they didn't lose what they love, than there wouldn't be any other point to surrender, except killing all the soldiers. Killing all the soldiers is effective, yet it is morally wrong, and could lead to more war. Yes you could talk your way out, but would that actually work, because the Union has tried it before, but has never worked ever. It is okay to left them suffer, because it is better than killing all of them. If you killed all of them, than there would be no reason to keep the country together.