It wasn't just Stalin's paranoia that the west was a danger for the USSR. During the Civil War, the West sent military forces to fight with the Whites against the Reds for goodness sake. Westerners had, between the Fascists and Communists, preferred the former over the latter many many times before the war. And it had this new Superweapon which, against the Japanese, it had shown it was willing to use.
And from the West's point of view, Communism was expansionist and dictatorial, and posed a danger to free men and free government (not to mention free enterprise). The Soviet Union had barnstormed Europe, and pushed all the way up to Berlin, were claiming the city as their own, and their leader said things like [In relation to the Soviets taking Berlin] "Tsar Alexander reached Paris".
It's just too much suspicion, too many differences, too many fears about one another. And in the post war world, the Soviets are a superpower, and America is a superpower. They have these massive spheres of influence: The US has the Americas, and Western Europe, Australasia, as well as the colonies of the great powers. The Soviets have continental Asia, Eastern Europe, and growing Communist forces around the globe chipping away at European Imperialism (many of which will succeed in time, such as Red China).
I will not say that the Cold War is something which cannot be avoided. But I'm saying its not necessarily the easiest thing to avoid. At some point, they're going to cross each other's paths, and some western power will become angered by or fearful of a Communist movements takeover of a colony, former or current, and bring in their buddies for defense with the USSR bringing in its buddies to defend its Communist friends. Perhaps you can minimize tensions and have it at detente levels persistently, but it seems like they're going to be in competition.