I think you have to go back a step and ask why Iran would blockade the Strait. Would they do it in response to just financial / trade sanctions? Or if the USA + allies implemented a physical blockade, stopping Iranian ships and confiscating cargo? If the latter I can see the Russians and Chinese interpreting THAT as being the initial hostile act and reacting accordingly on Iran's side. You have to remember that so far the Iranians have only threatened to block the Strait in response to Western sanctions, but they've never stated at which point they would react.
Last edited by COCL2; 15th Jan 2012 at 18:58.