Even America with all it's wealth and military muscle cannot afford a war with Iran. It's costing them too much already in Afghanistan and Iraq. The American public will not support another war so soon. Not when young soldiers are coming back in wooden boxes every day already from the two conflicts they are already embroiled in.
What the US will do (this time) is to make sure the UN is 100% behind a resolution to ban Iran from producing enriched Uranium and then it will try to get the rest of the world to start a trade embargo with Iran until in complies with the UN resolutions. That's the best the US can do or hope for.
Whether it will work is anyones guess.
It might help ease the tension in the area if Israel pulls out completely from the West Bank and the Gaza Strip. It's about time they put their differences apart and started to get on with one another.
This conflict has been going on since Biblical times. You'd think they would of had enough by now. Where's all this "Love Thy Neighbour" stuff they keep preaching?????