[BlueTemplar]

If your history only diverges around the bombings of Hiroshima and Nagasaki, it's hard for me to imagine a likely scenario where the conquest of Western Europe (minus UK?) by the USSR wouldn't qualify as "WW3". (Maybe if it immediately follows WW2 - for which I somewhat doubt the Soviets has the strength for, considering the heavy US presence... and even then this seems like hair-splitting ?)

[samus]

It really depends on whether the conflict stays restricted to Europe or not. A regional war is not a world war, even though Europeans might regard themselves as the navel of the world. As you say, a hair-splitting exercise for future archeologists (might actually be cockroaches or aliens) studying the leftovers of human culture.