In my opinion many people mistake the relevance of nukes - as in having them makes you "safe" or makes other countries consider twice before attacking you (countries that are nuclear powers or have alliances with nuclear powers).
It really doesn't, all it does is make things a lot more dangerous for the country that can't actually fight a nuclear war but does have nukes (and there are 2 countries that can fight a nuclear war on god's green earth)
If it's an Iranian discussion after all - you guys are badly mistaken if you think that getting nukes will deter the USA (or Israel, if it has USA's blessing) from anything. What it will do is make things extremely dangerous for Iran and somewhat more complicated for USA, and that's about all.
Lets' say you make 300 nukes, which is a huge number ..and USA decides against all odds to attack.Well, first they will go for the nuclear capability.Now, since you don't have boomers, ICBM's or, more importantly, no idea on how to actually fight a nuclear war (meaning troops that are protected, shelters, command structure protected, knowledge on how or were to dissimulate your nukes), the vast majority will be destroyed in the first strike. A couple might survive - then what? Launch them or accept their loss and fight a conventional war? If you launch, it will hurt a lot for Israel/USA, but they will pull through it. Iran, on the other hand, would cease to exit the next hour.
If you made boomers, ICBM"s, etc, all that would change is that the first strike will probably be nuclear, so that's even worst.
So what's the logical step for the Iranian state ? Risk a conventional defeat or sure annihilation, complete and forever?
Btw, this scenario also applies to China/India/Pakistan if they get in to a brawl with the big 2 - any of these countries will make god damn sure that the nuclear super power is assured about
not using nukes, in any scenario, never..in fact, I think they will tell them were the nukes are, just to lose them and get it over with..
Israel is somewhat different - unlike you guys, they can't afford to be defeated and occupied, so nukes would be all that's left int hat scenario..
Sorry for the long rant..
Edit: Muse, in the long run, Iran is the main adversary of Israel - they have the capability and potential. Besides that, they can replace Israel as the West's main ally in the area.
The Monarchies aren't a (big) danger, they will exist as something meaningful only until USA gets tired with them or Iran switches (hope I don't offend the Arab members, just my opinion)