All those bodys piling up, they certainly excert pressure on the ground. The war feeding the war can go on for quite a while (https://en.wikipedia.org/wiki/Thirty_Years%27_War) the idea that it is reason that finally extinguishes the flame is delusional.
What extinguishes the war, is that the resources of those spending for it, are rerouted to other theaters of the great game. So if you want to end the war in Syria, create internal strife in iran/russia/saudi arabia/ theWest or friction among blocks consisting of allies.
What extinguishes the war, is that the resources of those spending for it, are rerouted to other theaters of the great game.
Doesn't always have to be that, they can end by enough men of military age being killed or disabled on one side. The US Civil War (as much as a 1/3 of the South; we don't have good figures for it), WWI very possibly, certainly neither resulted in a rerouting to "other theaters of the great game."
In WWII the main combatants on one side were decisively defeated, occupied, and pacified, at least for a while for the Germans, and the following "great game" strife didn't consume a fraction of the human resources of the US and USSR that WWII did.
Then there's Carthaginian peaces, although of course in that case Rome always had some other frontier to make war on.
What extinguishes the war, is that the resources of those spending for it, are rerouted to other theaters of the great game. So if you want to end the war in Syria, create internal strife in iran/russia/saudi arabia/ theWest or friction among blocks consisting of allies.