Do you think it would have been possible for the united states and the soviet union to coexist peacefully in the postwar era

I dont think that the United States of America and the Soviet Union could be able to co-exist peacefully in the post war era. This is as a result of the different ideaological views shared by both countries with US leaning towards free and unlimited freedom of speech or association while the Soviet union leans towards communisim which tends to affect the freedom granted to its citizens.

There would always be that uneasy association between two countries.