well lets see the US flipped the bird to the rest of the world as the only industrial country other than Austr. to opt out of Kyoto protocol (even though it was the largest polluter)..
the same follows for landmine treaty, refusal to recognize the World Court but at the same time trying to use UN resolutions to justify its war on Iraq. (lets see,.. if some country were to mine New York harbor that would clearly be a terrorist act.. on the other hand when the instigator is the US and it mines Managuas harbor thats ok.)

(I know Iran isnt mentioned on the list but Id say the CIA backed overthrow of a democratically elected president and installation of a
dictator with a ruthless secret police- should be sufficient reason)

why not ask instead why Iraq and (North) Korea are/were considered part of an axis of evil? Along with Iran (a nonsensical situation anyway since an axis does not have 3 points, two of which are avowed enemies..)

the more likely reason is the 'successful defiance' of those states.