hmm...
nuclear war will result in the death of hundreds of millions of people...modern borders wont be a thing. but i can see how you changed them based on the powers of each nation. based off of what I know about the militaries of european powers, Russia will hold all of Europe. russia has enough man power and weaponry to take on the entirety of NATO (only if the United States is absent)
if we were talking about a non-nuclear war over europe and ONLY european powers, Russia will conquer all of them.