The conventional understanding you get from the media is that Israel is worried that a nuclear-armed Iran would pose a serious threat to the country's existence.
Israel War on Lebanon: 2006
Is that really what's happening, though? Another interpretation is that Iran might want nuclear weapons not to launch any such an attack but to prevent an attack on its country--nuclear deterrence, in other words. (Of course, it's important to note that there is currently no evidence that Iran is pursuing a weapons program.)
I was struck when I heard Israeli journalist Ronen Bergman bring up some of these ideas on NPR'sTalk of the Nation on January 30. Bergman is no outsider critic of Israeli policy; when he appeared recently on the NewsHour (1/12/12) and was asked about the assassination of Iranian scientists, his answer was: "I don't know. And even if I knew, I would tell you that I don't know."
Here's what he said on NPR, appearing to talk about his New York Times magazine piece on Israel and Iran:
NEAL CONAN: Chris, thanks very much for the call. Israel itself possesses, what, 300 nuclear weapons we believe, maybe more? Why does not deterrence work? Israel, of course, would retaliate if Iran were to use a nuclear weapon.
BERGMAN: I would assume that--oh, I know that most of Israel's leaders do not believe that Iran is going to use nuclear weapons against Israel. The problem is not the nuclear threat. The Iranians are not stupid. They want to live.... And I think that most leaders, and me personally as well, see that there are only a few people who believe that Iran would be hesitant enough to--sorry, brutal enough and stupid enough to use nuclear weapon against Israel.
The problem is that once Iran acquires this ability, it would change the balance of power in the Middle East. And a country that possesses nuclear weapon is a different country when it comes to support proxy jihadist movement. And these Israeli leaders afraid would significantly narrow down the variety of options from the point of view of Israel, just to quote one example coming from Minister of Defense Barak, when he said, just imagine--he told me in a meeting we had on the 13th of January in his house--said, just imagine, Ronen, that tomorrow we go into another war with Hezbollah in Lebanon like we did in 2006, and this time we are determined to take them out. But Iran comes forward and say, to attack Hezbollah is like attacking Iran, and we threaten you with nuclear weaponry.
Now, Minister of Defense Barak says it's not necessarily that we would be threatened not to attack, and we would decide to cancel the war, but it would certainly make us think twice.
In other words, Israel's position might be that an nuclear-armed Iran could make it harder to have future wars. That's a very different discussion from the one we're having now.