I don't care if they are a democracy and frankly I don't think that area of the world is ready for democracy. All I want is the Iranian government to cease any nuclear, biological, or chemical weapon development, reduce its military to a solely defensive force with no power projection ability, and cease supporting any terrorist organization. These three things happen and I would be fine with leaving Iran alone.
Question: If they supported the USAF after we committed aerial genocide against them - intending to use the terror of the bombing campaings to enact a regime change- would that be considered support for a terrorist organization?
Well I suppose you are entitled to your right to want a global nuclear war because that is what will happen if the Iranians build an actual nuclear weapon. If we don't nuke them then the Israelis will and that will be the spark for a global nuclear Armageddon.
The Iranians aren't stupid. They understand full well the dangers of nuclear weapons, and that every Gulf Princeling and Intelligence Agency will either be trying to sieze it or destroy it. As such, they would likely do the Pakistani method of nuclear weapon storage. In short, they would scatter all of the useful bits around the country as a fail safe to ensure that a singe maniac could not start WWIII. The Americans and Russians did similar things to ensure the safety of their nukes. (Or in Iran's case, making sure others don't steal it). Furthermore, unless the Iranians somehow got their hands on solid fuel rockets, they would be using highly corrosive liquid fuel in their rockets, like the Pakistani's. As such, we would have a roughly six hour window between Iran erecting the missile and the launching, same as with the last Kashmir crisis. I would be very suspect if we didn't have a plan, with or without NATO, to destroy the Pakistani rockets, let alone Iranian should they be prepared for launching.
Lastly, the only people in Iran who would use the weapon, provided some intelligence was used in the distribution of missile components*, would be the hardliners if they felt seriously threatened. Which, unfortunately, is exactly what is happened with people like Ahmedinijad. Moderates like Rafsanjani or liberals like Khatami struggle to get support** when just about everything coming out from America is "Lets sanction them like we did to Saddam! That really taught Saddam a lesson!" or presidential candidates seriously considering an invasion of Iran!
*which is highly likely given the fractious nature of Iranian politics and the divide between the Revolutionary Guard, the Supreme Leader, and the President
**Yes, I know they aren't actualy running, I just used them as two examples for the types of candidates.