The real question I have is if the USSR went to war with the US (and therefor all of NATO), would have all the Soviet states followed suit in conjunction with the USSR or could they have abstained?
Follow up: How much autonomy did the Soviet republics (particularly the "core" republics) have?
This varied depending on the country and the era. So somewhere like Poland in 1952 is going to have a lot less autonomy than Romania in 1975. But on the whole, they would have deferred to Moscow for most major issues, and going to war would have included that. Note that for the Hungarian Uprising in 1956 and the Prague Spring of 1968 it was not just Soviet troops invading, but technically actions by the entire Warsaw Pact (Romania notably did not participate in the latter, which goes with what I said).
The Warsaw Pact is probably more in line with what you are looking for, in terms of a war between the US/NATO and the USSR. It was the Communist response to NATO, and behaved largely in the same way: nominally a defence pact, but dominated by the major power and used to station troops in opposition to the other. So it is almost a certainty that in the event of a war, all states in NATO and the Warsaw Pact would have ended up in conflict with each other, as each of those treaties was created for that specific purpose.