This article speaks of the recent history of US threats against Iran and the possibilities of a US attack against Iran and the threats posed by Iran to the US currently.
My own opinion is that we should keep away from Iran and engage them diplomatically only. Iran has supported a nuclear free zone in the middle east, which seems like a great idea to the average joe, but the problem comes when we require Israel to disarm as well. We don't hold Israel to the same standards as everyone else. Pakistan and India have received our support recently in spite of their nuclear weapons programs. So apparently our allies can have nuclear weapons but those who we don't like can't. Of course, there is no current evidence that Iran is developing nuclear weapons. Everthing they are doing would be compatible with a legal nuclear energy program if the IAEA was actually there to observe.
Then there's FISSBAN which Iran supported and the US was the only country in the world to vote down at the UN. It would have stopped the production of nuclear weapons grade fissile material in all countries.
Going to war in Iran would be a bad move no matter how you look at it. We would further alienate ourselves from the world, kill masses of people, put our middle eastern troops in very dangerous circumstances, endanger our allies and rally support for radical islam. War is always a bad idea and this case is no different. Hopefully our collective amnesia will wear off before the fools in D.C. ruin the world.