A couple of quick points regarding the issues raised here. First, regardless of the regime in power, Iran has enormous incentives for seeking a nuclear deterrent. That is not even in dispute by anyone who seriously studies geopolitical issues in the region. In fact, all these reasons that exist for Iran to seek nuclear weapons are used to buttress the argument that Iran's nuclear program is indeed aimed for that purpose. Second, besides a nuclear deterrent, Iran -- a large country with 70 million people, with a growing industrial base already eating up on its oil production -- has equally valid reasons for seeking nuclear energy. The notion that Iran must make itself reliant on outsiders for its energy needs once its oil reserves (already being increasingly consumed domestically) are depleted is not one that most Iranians would find acceptable. Lastly, I personally doubt that Iran has any actual nuclear weapons program, although I am convinced that an added incentive for seeking such a large scale nuclear energy program is the knowledge that the program can be switched rather quickly, if necessary, to provide Iran such weapons. That ability, even if never utilized, will itself have deterrent value and that is all nuclear weapons are worth for Iran. The only evidence I have seen that looks even slightly suspicious is the fact that Iran has had the know how to produce the much more advanced P2 centrifuges, but yet besides some reserach facilities on P2 centrifuges, all the other facilities it has publicly declared and showed to the IAEA involve use of the less advanced P1 centrifuge machines. That leads some to suspect secret sites might exist, and if so, then Iran might already have the wherewithall to make nuclear weapons anyway. P.S. There was a report in the early 1990s that Iran had acquired 3 nuclear warheads from the former Soviet Republic of Kazakhstan. That report was later dismissed as being based on documents that appeared to be forgeries. More recently last year, however, the deputy chief of staff of the Russian armed forces made a rather strange remark to the effect that the whole hoopla over Iran's nuclear program doesn't make sense since Iran (supposedly) already has several "tactical" nuclear weapons! I assume he was referring to the reports in the early 1990s that I mentioned.
Democracies would bother simply because the sole fact that they have nuclear technology is a guarantee of better conditions in a negotiation. Dictatorships (but only the ones not sponsored by the US) need to have nukes in order not to be attacked - recent history has proven us that even if you don't have nukes, you're gonna be attacked, then what there is to be lost if you buy a nuke? - and not to have other countries involving in internal issues. See the diffference on how Iran and North Korea are treated, just because the second one has nukes. I don't think it's wrong for Iran to have nuclear technology, or even nukes, because they would just use them as a "trade currency" for their sovereignty. Everyone knows that if they launch a nuke against America or Europe, their country would be vaporized the next day.
Erm did you see or read the sum of all fears? Tom Clancy is said to have good connections to officials in the US gov. and poitics as wel as military, and it seems quite simple to me (the US also supported Pinochet in Chile, OBL and the Taliban against the soviets in Afghanistan and Saddam Hussein in his fight against Iran, the last two didn't change their agenda to much after the cold war, just added the Us to their list of enemies). Israel almost totally relies on the US and if the US would really want israel not to do something they could just cut back their aid and control israel... Even though Wikipedia.de says that France might have been helping Israel getting the nuke too...
Keep digging. Israel received little aid from America by the time she developed nuclear weaopns (nevermind that threating to cut off aid is a far cry from developing nukes for Israel in the first place, you've moved from "and it is obvious that the US helped a lot" to the USA didn't prevent it). http://www.fas.org/nuke/guide/israel/nuke/farr.htm
Ok, I was wrong about, you are right, sorry, didn't know enough about it... doesn't make it any better, though, does it? (never fight a lost battle ;-) )