However, it is not a new argument that greater Allied resolve during the Rhinelands or Treaty of Munich crises might have led to just such a decisive military defeat. At much lower cost.
Which doesn't mean a peaceful Europe necessarily--both Stalin and Mussolini have big ambitions.
Now, you have also to realise there is a certain degree of Red Scare in it. Staline would have gobbled nations.. but only if he could. He was paranoid but was also more focused on building a New Natoon first, then more later. If.
he would attack only with excuses and if anything to gain.
I say, expect one day attacks on Finlands, maybe Poland. But no Red Europe as we know, unlesss a Big War stsrt...
China and around, though, maybe...