It is a common theme in a non-nazi Germany to eventually have Stalin going crazy and attacking Europe.
And, when we see Stalin's actual record of aggressive wars, he doesn't appears very impressive: Finland kicked his ass. I know they lost in the end, but on their terms.
So, why is the "No Hitler = Commie Europe" theme so common?
My story, that I'm sticking to, is that Stalin would indeed be constantly preparing for an offensive war west--and never launch it, because the attack isn't ready (and he knows it) until there's a competent command hierarchy in place, and he'd keep purging generals and the followers promoted in the wake of their rise because an army competent to attack Germany is an army capable of plotting a coup against himself. Stalin just keeps building elaborate houses of cards and then knocking them down again.
As a general rule, Marxist-Leninist regimes tended not to actually attack, but to have both warlike rhetoric and preparations (fully justified by the resolution of anti-Marxist powers to bring them down) that in turn seemed to justify Western fears they would pull a Hitler any day now. But there's a different dynamic at work in these types of command societies than in capitalist-based ones, which indeed will probably attack someone someday soon once they've built up the arms for it.
Also, when someone else stirred up trouble, or attacked them, their responses tended to include opportunistic seizure of territory; this also makes them look Hitlerian, to someone who doesn't look at the context.