(1) preventing an Israeli attack on Iran;
This deal pretty much FORCES Israel to attack Iran.
(2) transforming the United States into a more forgiving, less imposing power;
Translation: Make all the bad guys in the world think they can do whatever they want because we are a paper tiger. Mission accomplished.
(3) establishing diplomacy as a great American good in itself;
We haven’t establish diplomatic relations with Iran
(4) making Iran into a great regional power; and
Well, yes it does do that but that is a distinctly bad thing
(5), ensuring the legacies of the president and secretary of state as men of vision and peace
He was carefull to list this one last, but in reality it is the ONLY reason for this and some guys “legacy” is a ridiculously stupid reason for a foreign policy decision
Give it a couple of months, you'll see. Then a state visit, either him over there, or some ayatollah over here. Think I'm joking?