Obama has gone out on a limb in order to be Israel's boy, but he is already out there. He can go no further. It seems obvious that, even though Obama is supporting Israel, he has no taste for it. An attack on Israel's part would likely change Obama's behavior concerning Israel. I would hope that Israelis are not so deluded that they think Americans would want to go to war with Iran in order to support Israel. That will not happen, especially in an election cycle.
Suspected Islamist militants attack Mali UN base, several dead (Reuters)
from the article: Iran expert: U.S. elections increase likelihood of Israeli strike