Now, the only way to go about this is for players to think on the opponent's shoes. I found more often than not, people take this game way too seriously. Going all out to fully destroy a realm. Give each other the chance, if they are worthy that is. Give them a survival chance. Take for instance how Fingolfin in Thalmarkin decided not to completely destroy Melhed. Why do so when you have opportunity for more different realms and characters surrounding yours. Exactly why i did the same to Fronen in this current war. As much as there are much grudges, i think the best way is for them to still survive. What else is there to play when they are all gone?
So my advice is to the winning side to step back a bit. Give the underdogs a little chance. You will see more fun in this then completely destroy them.
Stopping a war short of full destruction requires both sides to agree to stop it. There are quite a few examples of this, where realms have refused to surrender. (Luz de Bia on BT is the first to come to mind, but there have been others.) This forces the other realm to kill them. Or the realms voluntarily suicide. (Caerwyn on Dwilight did this, taking their regions to Asylon rather than continue to exist as a smaller realm.)
