Obama is putting enormous pressure on Israel not to fire the first shot. If it starts the world economy will completely tank as Iran closes down the strait. The whole world economy is based on the availability of cheap fossil fuels. A lot of countries need Iranian oil and the rest of the oil that goes through that strait.
If you're in the military, get out as soon as possible. If troops are sent to Iran they will be nothing but cannon fodder. It will be like northern Afghanistan. No one has ever won a war with the Pashtuns.