[Abraham]

Weird theory.

We may think that the US is in a nightmare situation in Irak, but the reality is that they won the war at a tremendous speed and an incredably low casualty number.
In an open fight against Iran things would hardly be different. The US military is not just a bunch of high trained professionals but has the intelligence, the mobility and the logistic capacity to outsmart and outmanoevre any troops they might encounter in the field. We don't even have to start talking about air force and maritime superiority.

The US might well lose the peace, but that won't do the current Iranian leadership much good, just as Saddam Hussein will probably be hanged or shot wile there's still unrest in the Sunni triangle.

Whenever a country fights the US the outcome of the war will be: the US wins and the opponent loses. That will be the result for years to come.
The difficult thing will be the situation after a fullblown war against Iran ends, the anarchy, the political infighting etc. But the nuclear threat will be removed and at a certain point in time that might be worth it.