On paper sure, we'll beat the snot out of them... but Iran is several times bigger then Iraq, so the US won't be able to 'shock and awe' Iran... and ride a line of tanks the length of the country. So, you should consider that the US will :
a) be fighting a losing war in afghanistan
b) be fighting a losing war in Iraq
c) and attack a country with a country who would be waging an invading force, they would be fighting with religious zeal, and not to mention that, how many Iranians live in the US, or American-Iranians, that would be recruited into terrorist cells at the call of the holy war going on across the borders.
d)
Deal with an ACTUAL invasion going on down south (Yes, fox uses soft language, but the chief of police went on the record to say that his men NO LONGER control that park because of the extent of the drug and human smuggling going on... that's an INVASION by any stretch)
e) on the verge of bankruptcy
So... EVEN IF, the war in Iran can be won easily, you must realize that if this war happens then that ALL the debt incurred during the conflict will be put on the head of the taxpayer, and you'll come back to a 95% tax rate... just to cope with the interest.... and you're gonna love it, cause at least there will still be sports and the illusion of freedom, so long as you don't question anything.
Also, how do you figure the rest of the middle east will view what's going on in Iran... they'll know, the US invades illegitmately, and if any of them have any sense of self-preservation, they will know that if they do not help Iran that they will be next. A few weeks ago I'd have said there was a good chance that Russia and China turn on the US in such a venture, but it looks as though they are being bought off and are starting to come to terms with it.
The only thing is whether or not the people will expect it... as bad as the oil spill in the gulf is, at present israel and the US have both began posturing nuclear capable ships in the region. Under any attack, you can bet that the iranians would sink some ships through the shipping lanes... you know, the ones that deliver enough oil to us to keep it cheap. Not sure how much that will affect the economy.
This one was a bit of fluff... I can't help but think about the stories of Hitler in the final days sending commands to armies that only existed on his maps.
Now, I don't doubt that the technological capacity of the US can overwhelm the Iranians, but Iran repesents a much more difficult situation. It's highly likely that nukes will be dropped on iran in such a conflict.... and there are other countries that also have nukes that are not exactly US friendly either. I can see this turning into world war 3... and frankly how the world will give in to the 'new world order'.