DJ, I reckon you are referring to the economic damage, not kinetic fighting. China won't fight us over Iran, and neither will Russia.
Not that China has to. They can easily apply economic and trade pressure to get their way.
The weakest of all weak things is a virtue that has not been tested in the fire.
~ Mark Twain
Everyone has a plan until they’ve been hit.
~ Joe Lewis
A warrior may choose pacifism; others are condemned to it.
~ Author unknown
"You don't feel lonely.Because you have a lively monkey"
"Ninja can HURT the Spartan, but the Spartan can KILL the Ninja"