I doubt that they will interfere PJ. China never interfered in US affairs in the Middle East except in the impotent UN security council, Russia latest major interference in the Middle East was in the 1973 war (Soviet Union back then) and they ended up on the losing side as usual, the Arab side, they will yell and scream this time and cause trouble in the UN but I do not see them rushing to defend Iran miltarily for a simple reason: They cannot do it.
-PJ