I agree with a few other here, one on one no other country stands a chance. These days you will need a powerful blue-water Navy to fight in any war. The only other country that comes close to the US Navy would be Britain. We could fight a war from miles away while still at sea or in the air without ever touching foreign soil. We've been fighting wars that way for quite a while now, while still sending ground troops after the initial Air/Sea bombardment.
True, Russia and China would be formidable against the US, but you have to remember, if they teamed up, then so would the US and NATO, then it would be more even and equally devastating for both sides. Something I hope never happens (as I am in the Navy...lol...though I see myself being off the coast of North Korea with the way things are going now)
Another thing to remember: The military power of a lot of countries can never be truely 100% known BTW because everyone keeps things under wraps (including the US) until that crucial time comes...
