I part ways with you on the highlighted. Prestige, yes, but I believe you can replace deterrence with blackmail. Who are they deterring from? We removed their only real regional adversary.
I trust nK with nuclear weapons more than I do the Iranians. I don't believe they'd easily hand any over to terrorists, either- too easy to attribute. But, provoking Israel and holding Europe hostage is not outside the realm of possibility. Iran is both xenophobic and nationalistic. As you well know, they are Persian, not Arab. They have a past history of willingly absorbing punishment in quest of a goal. They have an institutionalized pathological hatred and distrust of the Americans, the British and especially the Israelis. Their foreign policy is guided by a misguided idea of where they fit into the world and what the world thinks about them.
The man on the street in Tehran might not be enamored of the government, but attack them and they will pull the wagons into a circle through their nationalism. We aren't going to change any regimes by bombing, and our government knows that - in spite of anything Hersh says.
Iran is going into a full court press firing up thousands of centrifuges to enrich. There is one and only one reason for them to do this.
Problem is, with Iran there are only so many choices, and all of them are bad. They could be dealt with if there were truly a unified effort between the US and certain European nations, and China. But, Europe will continue to lie around with their head in the sand and figure that if push comes to shove, the US will take care of it. China might become more of an ally than one might think, now that they have firmed up so many new oil deals with Russia.