Not going to happen. The effects of an EMP going off above an industrialized nation are not going to be all that far off from using conventional nuclear bombs. Israel making use of precision strikes, or even a tactical nuke against the nuclear weapon facilities of Iran is one thing - effectively signing the death warrant of millions is another altogether.
Most of the nations of the world would be content to grouse publicly about Israeli warmongering for the prior, while secretly being thankful that the Israelis took care of it. The latter? Israel would wind up an international pariah that would make North Korea seem like a globally accepted nation by comparison.
Listen, much as I fear the outcome of such a thing, the only way to defeat your mortal opponent is to utterly wipe them out.
Just like was done in WWII. Civillians, everything.
If it attmepts to fight a war like the USA fights modern wars, it will lose, just like the USA loses.
If it goes war against Iran, it is going to have to wipe out many, many, many people, and it will likely lead to things I cannot even imagine.
At least a death warrant for every electronic device in Iran.
For EMP effect it must be detonated at extremely high altitudes to cover a large area. A nuclear detonation many kilometers above the earth will not have any physical damage to structures on the ground. The radiation will be minimal. Follow the link for a good explanation of EMP.
http://www.fas.org/nuke/intro/nuke/emp.htm