> I wonder what is your opinion on the similarities between American Capitalism vs USSR State Socialism during the cold war?

I'd say that a good point was made by Marxists I've known (not of the Leninist/Stalinist persuasion!) who referred to Soviet-style Communism as "State Capitalism" and traced the failure directly back to Leninist vanguardism recreating one of the central problems of capitalism in that it produced a narrow elite class that exercised control of the means of production and ordered society for its own benefit.

I would say that in many ways, during the Cold War, the "capitalist" mixed economies of the West -- even, though less so than some if its European allies, the US -- were more substantively socialist than the USSR and its allise following the same basic structural model.