The difference between Iran and N.Korea on one side and Israel, India and Pakistan on the other is that the former two were signatories of Non-Proliferation Treaty and by doing so promised not to develop the nuclear weapons - and lied. The three nations who did not sign the treaty did develop the weapon, which was and is their full legitimate right. Nobody seems to mind India and Pakistan, which are much more likely to use it on each other. Why such an attention to Israel then?
Shaffir to Herzog: Opposition failed to show leadership in political battles against PM (Haaretz)
from the article: Iran: World can't block our atomic program while Israel has nukes