If you want to take the religeous point of view. Geopolitically and militarily, all of the arab armies combined have already tried unsucessfully 3 times. And it is not like they got any better at real warfare.
They don't need "real warfare" if they have nukes. If Iran drops a few nukes on Tel Aviv and a few other cities, followed by an immediate all out attack from Syria, Israel would be in a much worse position then they were in '67. Sure they could take out Tehran and Damascus, but that would only get the rest of the Muslim world in on the war too. Could they pull off what they did forty years ago, after having their cities devastated by a nuclear attack?
Where it gets interesting is when China comes out on Iran's side.