Whoa, Vance.
You need to read page 15, “Powers that begin the game neutral”
There it is clear that Russia cannot attack anyone nor can it take over pro-Allied neutrals anywhere on the Europe map until at war. “Movement: A power that is not at war can’t move land or air units into neutral territories.”
Also, it’s not when ANY Axis power attacks Russia, it must be Italy or Germany declaring war to bring Russia into the war on the Europe map.
So there is no invading of any neutrals, Turkey, Sweden, or anything until round 4 if the European Axis don’t allow Russia into the war until then. :-)