I have wobbled on the implications of Iran developing a nuclear weapon but I currently believe allowing Iran to develop nuclear weapons would be a dangerous precedent. The Iranians would constantly terrorize the western world and its neighbors and they are so unstable that they could never be trusted to abstain on the basis that we would hit back following their attack. Moreover they could smuggle a bomb into a country and blow it up even if they could not launch it with a long range missile. Why not simply tell them that if they do not allow open inspection and observers on the scene they could scratch one of their cities; and name the city and the time. Would Iran take the risk? Maybe they would assume we were bluffing but not risk the second or third city. Once this is done that will close the door to Iran and any new nations developing nuclear weapons. It is absolutely essential to end development by any nation of nuclear weapons. If this plan is followed it will end any new development of nuclear weapons. I cannot think of a better nation than Iran for being the precedent for making this happen.
4.2-scale earthquake felt in Dead Sea, Jerusalem area (Haaretz)
from the article: U.S. army chief heads to Israel as fears over attack on Iran mount