Hey guys why doesn't the US go and invade Iran over this (since Iran more less attacked their country, the fact it was foiled is irrelevant), or maybe not because Iran is best friends with China, Russia, North Korea and most of the Arab World.
The US have got themselves way in over their head in Arabia and the Middle East. I like the way that us British are pulling out now under the pretence of "victory", if you have to go on Newsnight and Question Time to explain how we have achieved "victory" then the chances are, we havn't.
This whole "War on Terror" or as I call it, "Vietnam - Part 2", has been one big balls up. All that has happened is a melting pot has been creating in the Middle East and now most of the emergent nations (China, India, Pakistan) have really turned against the west, hence the fact Iran are brazen enough to sanction an attack on the US, they know that the UN and the US and NATO are poweless to administer repercussions.
The US is practically owned by China thanks to all the debt it's in with them, Britain is tied up in the EU and the EU can't upset Russia (who basically have the monopoly on the European power supply - except maybe Germany, but Germany don't really care for the US's problems), The Arab world will always side with it's neighbours (casing point: Six Day War, Yom Kippur War, Arab-Israel War, Suez Crisis) and plus they support Palestine and Lebanon, where as the US support Israel, Russia along with China and North Korea are long standing supporters of Iran.
Oh and one major difference where the US will do absolutly nothing about this:
Iran actually have Nuclear Weapons unlike the cardboard tubes that Saddam was hoarding in Iraq.