Israel: Iran still mulling whether to build nuclear bomb - Haaretz Daily Newspaper | Israel News
So in spite of all their calls for war, Israel still aren't convinced that Iran has even made the decision to build a nuclear weapon.
Iran do not need to build a nuclear weapon as they have achieved a conventional deterrent to potential Israeli aggression by upgrading the S-300 and other missiles and fitting them with GPS.
this means that they can be aimed with much more accuracy and their range is easily enough to strike at Israel's nuclear and biological stockpiles, including the Dimona nuclear power station, a situation which would probably cause the Israelis to think twice before launching another Operation Cast Lead or Lebanon war.
I believe this is the real reason for all the Israeli/US sabre rattling because nobody is allowed to threaten Israel's primacy in the region.
Whether Iran wants to eventually build a nuke is pretty irrelevant. Eventually action will be taken to take out their conventional missile sites and return Israel to being the major military power in the Middle East.