While I am mostly focused on the activities of the individual here, I think you do present some valid points. In theory (but really only in theory) the USA expresses a somewhat agnostic philosophy in the 1st amendment, and the USSR was officially atheist as I recall, though otherwise officially atheist states are rare.

I say "In theory" about the USA because even though it has official separation of church and state, bizarrely politics in the USA are far more influenced by religion than they are in Canada or the UK of many other European nations that don't have that separation. (This does not imply that not having separation is good, since obviously we still have plenty of nasty theocracies.) But what it does mean is that oppression or enforcement of religion seems more tied to the national mood than to any properly chosen principles of good government. The USSR was a dictatorship; its policy on religion was secondary. Canada, which has a Catholic school system and a head of state who is the head of the Church of England, probably has greater freedom of religion in many ways than the USA.