Fishrrman "why the heck not™?" prediction:
The only effective way to neutralize Iran (and its nuclear weapons program) is with nuclear ordnance. Sooner or later this is going to become quite obvious.
The $64 question is whether Israel will be wise enough to make that decision before or after Iran HAS working weapons and a reasonably-reliable system to deliver them.
Will the Israelis act in time?
The unfortunate geopolitical calculus is as follows.
IF Israel does a nuclear pre-emptive nuclear strike against Iran, they will be seen as the 'bad guys' and be open to reprisal strikes by any nation with a sufficient combination of antipathy toward the perceived aggressor and sympathy toward the "victim" to act. Whoever is attacked using a preemptive strike will be seen as the victim.
IF Iran strikes first, with (hopefully) complete interception of those weapons, and it is later documented after that interception that the missiles or aircraft carried nuclear warheads, then the destruction of Iran's nuclear program would be seen as justified in the eyes of the world, or close enough that there would likely be little done militarily in retaliation. (Nuclear bunker busters would be the preferred technique, to minimize civilian deaths, downwind fallout, and effects on neighboring countries: noting that not all Iranians are in league with the theocracy there, and many are opposed to it.
In the event the Iranians succeeded in delivering even one functional nuclear device and detonating it over any part of Israel, the gloves come off, and any nuclear response would be considered 'justified'.
