Less likely than some people think, according to Amir Oren:
You don't need to visit Sheldon Adelson's casinos in order to bet that the Israel Defense Forces will not be sent on a large military operation against Iran - "not at this time," as politicians would quickly add. Prime Minister Benjamin Netanyahu, the Winston Churchill from Jerusalem, has not started to prepare either his country men or his colleagues for the blood, toil, tears and sweat. His belligerent talk has thus far frightened Israelis more than the Iranian regime.
Nearly all countries oppose Iran having a nuclear bomb, but not a single one - especially the one that would need to approve an Israeli operation - believes an IDF operation this spring is a necessary evil. It isn't that Netanyahu and Defense Minister Ehud Barak have despaired of launching one. In order to launch a campaign, they need approval from more than half the 14 ministers belonging to the ministerial committee on security affairs. If the Yisrael Beiteinu ministers were to leave the government should Foreign Minister Avigdor Lieberman be indicted, there would be 12 ministers left on the body. Then, Netanyahu and Barak will need to pull five more ministers onto their side in order to block those considered opponents of an attack.
I think it's perfectly plausible that Netanyahu could order a strike soon, though I'm less sure of that than either Leon Panetta or Ronen Bergman. In part this is because I tend to think it is something close to impossible for any Israeli prime minister to launch an attack that could have adverse consequences on the United States without first getting the approval of the U.S. Netanyahu, who is a keen student of the U.S.-Israel relationship -- and who knows, as all Israeli prime ministers in recent memory have known, that the U.S. is Israel's indispensable ally and patron -- simply couldn't afford a rupture with Washington, unless he was absolutely confident that his only choice was between a break with Washington or a second Holocaust (a fear I wrote about in this Atlantic story). I write about the myth that Israel is a purely independent player in this drama here, by the way.