As a result of WW2, the Soviet Union lost the military supremacy we had built up on the eve of the war against Germany:
After the war, despite all the efforts, we have never since managed to regain this level of strategic advantage over the West.
As a result of WW2, the traditional American isolationism ended. The US took global leadership in preserving the new world order. The old Leninist strategy of “let them fight each other for us to pick the spoils” would no longer work. The USSR faced NATO, a global coalition of democratic countries possessing an economic and military muscle that we, in the long run, could not match. It was now the turn for our new Chinese friends to push for a nuclear US vs. USSR showdown in the hope of picking up the spoils in the after-war rubble.
History gave the USSR no new chance of running over Western Europe. Eventually, the Cold War bankrupted us.