Iranian President Imajihadi (or whatever his name is) seems pretty confident that the US won't act against him. In fact, he says, Iran is "invincible," at least insofar as the US is engaged in Iran and Afghanistan. At least, one hopes that's what he means.
Of course, Iran is the farthest thing from invincible, and if we need to act against them, we'd muster up the troops and material to do so. We could just bomb their nuclear facilities back to the stone age, if we wanted. And so, once again, Imajihadi shows himself to be rather mistaken in his premises.