IRAN DECIDES TO GO FOR THE BOMB
Experts say a raid would only delay, not destroy Iran's program. And once it had recovered, Iran would probably seek to develop nuclear weapons. Jon Alterman, director of the Middle East program at Washington's Center for International and Strategic Studies, told Reuters Iran would redouble "efforts to develop a deterrent so it never happens again."
OIL PRICES SOAR, JOLT FINANCIAL MARKETS
A strike on Iran and Iran's response, including attempts to close the Strait of Hormuz, which is vital for oil shipments, or an attack on Saudi oilfields, would lead to a sharp rise in oil prices that could seriously harm the U.S. economy, jeopardizing PresidentBarack Obama's chances for re-election.
Saudi Arabia would be forced to use all its spare output capacity, a crucial safety cushion for oil markets.
But the most serious fears debated at oil trading desks include the possibility of Iran mining the straits, attacking ships as it did during the Iran-Iraq war, or challenging the legality of the passage of some vessels through its territorial waters.
In the event of a big stoppage the consuming nations'International Energy Agency would very likely release emergency government stocks to tame prices, as it did in June last year when Libyan output was lost.
Israel's Ayalon argues that a nuclear-armed Iran would pose a greater threat to the oil market as it could dictate prices. "It will be the end of the free flow of oil from the Gulf."
IRAN HITS BACK IN THE GULF, LEVANT, POSSIBLY ASIA
Tehran has warned several times it may seal off the Strait of Hormuz, choking the supply of Gulf crude and gas, if attacked or if sanctions mean it cannot export its oil.
But many experts say Iran's leaders will be looking for ways to harass enemies and cause disruption while falling short of triggering massive U.S.-led retaliation.
Possible Iranian actions could include harrying tanker traffic in the Gulf with fast attack boats, seizing uninhabited Gulf islands claimed by other states or grabbing hostages from passing civilian or military ships, stoking trouble in Sunni Muslim-ruled Arab states with restive Shi'ite Muslim communities and orchestrating attacks on U.S. forces in Afghanistan or elsewhere using militant "proxies" such as Hezbollah.
If the Iranian government interprets the strike as a fully-fledged attempt at regime change, it might adopt a more muscular response could include ballistic-missile salvos on civilian and military targets in the Gulf.
US GETS SUCKED IN, MAY ITSELF BECOME TARGET
Obama also would likely come under intense domestic pressure to back Israel's actions and come to Israel's defense if Iran succeeds in landing missile attacks on Israel's territory.
In a 2009 study for the Council on Foreign Relations, Middle East analyst Steve Simon, who is now Senior Director for the Middle East and North Africa at the U.S. National Security Council, says that the United States would probably become embroiled militarily in any Iranian retaliation against Israel or other countries in the region.
Experts say Israel alone does not have the firepower to kill off Iran's nuclear program and any U.S. help in that effort would therefore be very welcome. A study by former senior British intelligence official said the "The US would be assumed complicit, and would become embroiled in defending Israel against a counter-attack. This would stretch theU.S. military."
STRAIN IN ISRAELI-WESTERN TIES
In November, the top U.S. military officer told Reuters he did not know whether Israel would alert the United States ahead of time if it decided to take military action against Iran.
General Martin Dempsey, chairman of theJoint Chiefs of Staff, also acknowledged differences in perspective between the United States and Israel over the best way to handle Iran.