I suspect another reason. Israeli hawks have been worried about the Arab spring, because they don't want to see the status quo changed (particularly losing their claim to fame as being the only democratic country in the area, which has some appeal to those of us with nuanced views on Israel (open society is good, racist laws and policies are bad)), they're worried about close US/European ties to these new governments, and they're concerned about how authoritarian governments that used Israel as a boogeyman to distract from domestic ills will work out now that the divide between power and the people is set to shrink. I believe Israel is attacking Iran (apart from the surface reason, which is also bad) to drive a wedge between these new states and the west.
This wedge doesn't even need to be taken to the level of actually launching the attack; testing the water will provoke furious debate in America and Europe between people whose interest in Israel is my-ally-right-or-wrong (AIPAC and J-Street are both quite strong here) and those who are seeking to better the world more impartially, and Israel will be able to test the waters while the new governments are still in their formative stages (giving us a reasonable answer to "why now?"). Of course, Netanyahu will see political benefit to doing it, and I expect him to actually attack.
I find this more than bothersome. Israel has nukes too, and deterrence actually would work reasonably with Iran (although given that there is a standing fatwah against any use of nuclear weapons, I don't expect Iran to ever use such weapons). Israel never should have been America's unconditional friend, given its inability to move beyond the 18th century "ethnic homeland" garbage. This is simply another reason the west needs to scale back its relationship with Israel so they can't be an ass and rely on the west to bail them out. In the short term, I would suggest cutting all military ties and pressuring them either to become a bi-ethnic state without racist laws, or to give up East Yerushalaim, dismantle all the settlements (as forcefully as necessary), and figure out some recompense for the Arabs they've screwed over. Personally, I prefer the one-state solution, but whatever can lead to a workable peace.
If Iran should not have nuclear weapons, neither should Israel. If Iran can be attacked like this, Israel can be attacked like this.