I doubt Russia or, especially, China would actually get involved in a shooting war between the U.S. and Iran. They'd bitch and moan, along with France, but that's all they'd do. It's all about the almighty $. Russia and China might sell arms to Iran but its because they need the cash. Ultimately an all out war between super powers, even a conventional one, would be disasterous for the economies of everyone involved. When push comes to shove they'll kick Iran loose. Decent relations with the U.S are far more valuable in the long term than any realationship with a bunch of camel jockeys. At least that's my theory. I'd be more worried about good ol' GW launching an invasion of China because he got a bad fortune in his cookie.