When asked Friday night by Kenneth Pollack of the Saban Center how long a military attack on Iran might postpone it from going nuclear, Leon Panetta, the secretary of defense, responded: "(A)t best it might postpone it maybe one, possibly two years. It depends on the ability to truly get the targets that they're after. Frankly, some of those targets are very difficult to get at... Of greater concern to me are the unintended consequences, which would be that ultimately it would have a backlash and the regime that is weak now, a regime that is isolated would suddenly be able to reestablish itself, suddenly be able to get support in the region, and suddenly instead of being isolated would get the greater support in a region that right now views it as a pariah."
He went on to say, rather crucially (emphasis mine): "Thirdly, the United States would obviously be blamed and we could possibly be the target of retaliation from Iran, striking our ships, striking our military bases. Fourthly - there are economic consequences to that attack - severe economic consequences that could impact a very fragile economy in Europe and a fragile economy here in the United States."
Panetta is stating fairly clearly the Obama Administration's belief that an Israeli attack on Iran would hurt the American economy. What Panetta was doing at the Saban Forum was throwing the mother of all brushback pitches. Without saying so explicitly, it seems as if he is threatening Prime Minister Netanyahu with a rupture in relations between the U.S. and Israel, should Israel unilaterally attack Iran. And since Israel's close military relationship with the the United States is the cornerstone of ts defense posture, Netanyahu cannot, and should not, risk a rupture. Of course, Israelis might feel better about the situation if they believed the Obama Administration was moving quickly to sanction Iran's Central Bank -- the real "crippling" sanction -- but it is not moving quickly in that direction.