POSSIBLE RESULTS OF ATTACK ON IRAN

"... The possibilities include:
* immediate withdrawal of Iran from the non-proliferation treaty and a wholehearted effort to develop nuclear weapons as quickly as possible - leading to further action by the United States and Israel, and a long war.
* action against US forces in Iraq, through Shi'a militia intermediaries on a far larger scale than at present.
* direct involvement of Iran's Revolutionary Guards in Iraq.
* closure of the Straits of Hormuz, causing a steep increase in world oil prices.
* aid and encouragement to Hizbollah in southern Lebanon (especially if Israel was involved in the attacks).
* paramilitary attacks on oil facilities in western Gulf states...."
http://www.opendemocracy.net/conflict/us_iran_4306.jsp