Too many interests would be damaged by that attack, lost revenues and trade would be into the trillions of dollars. He would be shut down before this would ever come to fruition.
See the article below for supporting evidence.
http://www.atimes.com/atimes/China/GF04Ad07.html China and Russia have invested $100's of billions of dollars into Iran. China has sold military armaments to Iran including surface-to-air missles and surface-to-surface cruise missiles. Additionally, China and Russia have and are participating in joint military exercises, with the intent of countering Mr. Stupid Fuck's possible attack.
I think this is all saber-rattling coming from an impotent piece of shit who is trying to distract the American public once again from the cluster fuck he created in Iraq. He did it with 9-11, by attacking Afghanistan. When it started getting shitty there( I mean has anybody heard much about Afghanistan recently, other than record opium production courtesy of our CIA), he attacked Iraq. Now its getting fubared in Iraq, hey look what's next dorr. This time, however, he fucked with the wrong country. Iran will be no pushover, with the military support and financial backing of both Russia and China, along with the vehement support of the entire rest of the world. The immediate penalty would be severe, Venezuala would cut off our entire oil supply; without their oil supply our internal oil(gasoline) prices would skyrocket. Theoretically, this could cause a civil war in the US.
I see it this way, if I wake up one morning and hear we have launched a full scale attack on Iran, I'm putting my head between my legs and kissing my ass goodbye. Then I'm probably gonna head for the hills for awhile. Anyway that's my forty-two bits.
http://www.atimes.com/atimes/China/GF04Ad07.html