well iran is "not allowed" to have nukes, because the iranian clerics call America the Great Satan and they mean it.
Iran and America were best of pals back in the days of the Shah. in fact when you look at the weapons they have, their best weapons are american weapons purchased by the Shah when America was willing to sell the very best to her best buddy. even though they are old, the Shah got only the best and with currently iranian upgrades ands modifications, they are still ok. anyway back in those days, iran was one of the few muslim country that didnt go apesh17 when they heard the word "israel."
But then Khomeini came along and since Iranians didnt like the Shah, they of course hated America by way of extension.
Then came Saddam Hussein whom we all know today to be an @ssw1pe, but he was even more of an @ssw1pe back then and massacred a lot of Iranians. Then being a total doofus, he actually started losing the war to a nation that was depleted of a major portion of its best military minds, because the clerics took them out for being the Shah's men. And here America started to sh@t in her pants since, we are totally dependent on muslim oil back then just like today, and we said, "hey, at least Saddam dont call us the Great Satan.". So America supported Iraq and Saddam was saved from a total @ssr@page by the Iranians. of course the Iranians now saw us as The Even More Evil Great Satan.
so today we here in America is scared of Iran and they are scared of us. even though we destroy the taleban and Saddam whom they absolutely despise. but now Iranians are more easy going and are like, "well dudes, we are muslims, but we also use internet for surf for p0rn just like you"
and that is the problem for the clerics of Iran. the young people of Iran just want to surf for p0rn like the rest of us, smoke some hookah, watch some football, and dont give a sh17 about watching some old boring imams giving endless sermons on telelvision. so what can the clerics do? now they have to keepmbashing America, because it's good way to stay popular. "hey if you are a patriotic Iranian, you must hate America!". and of course some iranian kid is going, "oh, i love my country! ok, Death to Amreeka!"
Then America flips out and say, "no nukes for Iran for God's sake!". then the clerics say, "oh, American hypocrites!". and all those patriotic Iranians band around the clerics saying, "oh we love Iran! we need nukes!"
and that is the short story in a nutshell. but real story gets even more complicated. you will need to ask an Iranian for the finer details to the saga.