Dalia Dassa Kaye on some of the complexity regarding the Israeli position on the possible Iranian nuclear threat:

[I]mportant divisions are emerging within the Israeli strategic community over how to deal with the Iranian nuclear challenge. U.S. politicians may feel comfortable with framing Iran as an existential threat to Israel, but not all Israeli leaders do. An increasing number are concerned that overplaying the “existential threat” card may erode Israel’s own ability to deter a future Iranian bomb, suggesting that Israel could not protect itself from a nuclear Iran. Many have stopped using this term in public. Other leaders prefer to talk about Iran as a global problem rather than focus on Iran as Israel’s problem in order to enhance the international coalition that has emerged to pressure and isolate the Islamic Republic.

Perhaps the most interesting debate in Israel today is over the question of a military strike. Last year, former Mossad head Meir Dagan publicly argued that a military attack would be a “dumb idea,” that would trigger region-wide conflict. But well before Dagan’s statements, Israeli leaders and analysts had been quietly debating the merits and feasibility of a military strike. For some, a military strike would be worth the costs even if the nuclear program were only delayed (very few believe it could be destroyed); they think that the risks of Iranian retaliation against Israeli and U.S. targets may be exaggerated. Others believe that a delay in the program could be more effectively achieved through other measures, including sabotage and continued diplomatic and economic isolation, with far fewer costs and risks of wider regional military escalation.

It is difficult to know who has the upper hand in Israel at the moment. Reports suggest that Prime Minister Benjamin Netanyahu is sympathetic to striking Iran if the alternative is an Iranian breakout capability under his watch. But it is not clear that the Israeli military and certainly Israeli intelligence analysts share this view; many may in fact hold positions closer to U.S. assessments that are less alarmist about the timeline of the Iranian program and more cautious about the utility of a military option. Much has been made over differences between the U.S. and Israeli threat perceptions of Iran, but in fact these internal Israeli divisions suggest that the gap may not be as great as some suggest.

More here.