that is the difference between theory and practice. Von Neuman is a genius of theory, and the idea of atomic bombing of USSR into oblivion has significant theoretical appeal even with hindsight of today. Eisenhower was battle experienced military general, not far from [if not the] pinnacle of practice. Eisenhower saw USSR soldiers, and the history of the guerilla war on Nazi occupied territory was well known. As long as few Soviet soldiers or even just some general population survive the atomic bombing ... https://en.wikipedia.org/wiki/Attack_of_the_Dead_Men:
"Over twelve battalions of the 11th Landwehr Division, making up more than 7000 men, advanced after the bombardment expecting little resistance. They were met at the first defense line by a counter-charge made up of the surviving soldiers of the 13th Company of the 226th Infantry Regiment. The Germans became panicked by the appearance of the Russians, who were coughing up blood and bits of their own lungs, as the hydrochloric acid formed by the mix of the chlorine gas and the moisture in their lungs had begun to dissolve their flesh. The Germans retreated, running so fast they were caught up in their own c-wire traps.[1]"
that would open the game for China who was quickly coming online - until of course China is bombed too. Though no occupation could cover the territories beyond Ural Mountains, so China would become the main player either way, and much larger than it is today. Basically USSR would be like US in the "Man in the High Castle" - the part close to Europe occupied by US/NATO, large unoccupied wild middle and the huge East by China. Such configuration had already happened centuries ago - Crusading European Knights on West and Mongols on the East https://en.wikipedia.org/wiki/File:Kyivan_Rus%27_1220-1240.p...
"Over twelve battalions of the 11th Landwehr Division, making up more than 7000 men, advanced after the bombardment expecting little resistance. They were met at the first defense line by a counter-charge made up of the surviving soldiers of the 13th Company of the 226th Infantry Regiment. The Germans became panicked by the appearance of the Russians, who were coughing up blood and bits of their own lungs, as the hydrochloric acid formed by the mix of the chlorine gas and the moisture in their lungs had begun to dissolve their flesh. The Germans retreated, running so fast they were caught up in their own c-wire traps.[1]"