Perhaps humanity is lucky that Hitler was uncompromising and deluded by his belief in the so called "force of will". Had he been more strategic and connected to facts rather than believing his own propaganda, he may have found a way to some sort of compromise to pause the war in the west while he retooled Germany for a world war before Barbarossa. The outcome be may have been different, a stronger Germany, perhaps a more developed nuclear program. I'm sure that this has been the subject of numerous dime store novels.

Stalin apparently would have accepted an armistice in 1941after losing a lot of territory, I think before the Kyiv encirclement. This was likely before he realized that it was a war of annihilation. I think that I read about this in Montefiore' s book Red Tsar.