If Iran goes nuclear and is not stopped, the Sunni oil Gulf will demand their own nuclear arms. Saudi Arabia will get them from either the US or elsewhere. With all the oil money there will be multiple sellers of nuclear technology. Iranian Shi'ite hegemony will not be accepted by Sunnis. When Saudi Arabia gets them and signs mutual defense agreements with Kuwait and Arab Emirates you will see a spur in lessen states like Egypt and Jordan- both backed by the Saudis and Pakis. With oil money at an all time high, Saudi Arabia will spend for WMD as they spend on malls and Mercedes / BMWs. Syria will go nuclear - thus possibly hezbollah. With nuclear weapons in Saudi, Persian, Surian. Egyptian, Jordanian, etc. hands the prospect of a nuke war becomes probable rather than possible. A nuke war in the Middle East- regardless of the 'winner' or 'loser' will cause chaos in the West due to its effect on oil. That is why the US cannot permit Iran to go nuclear and why Bush will attack in 2008.
Five people killed in car crash near Hebron (Haaretz)
from the article: Poll: 72% of Israelis back use of nuclear arms in certain circumstances