President Obama and Panetta are said to have cautioned the Israelis that the United States opposes an attack, believing that it would derail an increasingly successful international economic sanctions program and other non-military efforts to stop Iran from crossing the threshold. But the White House hasn’t yet decided precisely how the United States would respond if the Israelis do attack.
The Obama administration is conducting intense discussions about what an Israeli attack would mean for the United States: whether Iran would target U.S. ships in the region or try to close the Strait of Hormuz; and what effect the conflict and a likely spike in oil prices would have on the fragile global economy.
The administration appears to favor staying out of the conflict unless Iran hits U.S. assets, which would trigger a strong U.S. response. Read more at WaPo
It should be noted, if a republican were president, Israel would not only be encouraged to attack, the U.S. would be 100% on board military action. That is the way republicans solve problems:
