Communist would have been a better word to use than Soviet. Soviet was relatively specific, but broad swaths of the world got labelled communist. While it's true that the Soviets were more than boogeymen, I think that the broader point stands that Americans (and everyone else really) tend to have some convenient, reductionist label to apply to "others" that is broadly taken as a synonym for "evildoer". "Terrorist" is the fashionable label today.