Yeah but not so sure about that...
USA has DOZENS of military bases in Europe.
I don't see Russia ignoring that... War between the two would be accross Europe not accros the ocean :/
Don't forget that the Russians are having nuclear-tipped ICMBs such as the SS-18 Satan, which are capable of targeting the mainland US. But the American military bases in Europe and Japan are easier targets for the Russians.
If we consider everything that happens in the world, i do not think it will happen... i mean nuclear war. But lets think for a moment that it happens. I think that Russia would win over United States of America. Mostly because Russian people are smarter... That is the main reason. Maybe America have expensive technology, but brain is what matters.