One cannot avoid seeing that the situation with Iran is only narrowing the options Israel has to deal with that threat. With our present administration now taking a hostile tac with Israel, only the worst can be expected from it. Ez 38 conditions are becoming more and more set.
while a nuke may not destroy underground Iranian facilities - the emp, surface destruction and residual radiation will make it very difficult for operations to continue without a LOT of clean up.
Naturally, if Israel has to resort to those measures all Hell will break out in the persian gulf as well as gaza and Lebanon. That may be the stratigic play-off. Israel believes it can handle Hamas / Hezzies / Syria conventionally, and has an adequate missile shield to defend against Iranian counter strike attempts. They are not worried about the persian gulf - where the oil sheiks hate Iran about as much as Israel. So let them handle the problem in the gulf.
By design, most likely.