IMO, this is a mortal threat. Israel would be perfectly justified in a mounting an all out pre-emptive nuclear strike against these medieval madmen. And if that should happen, we should join them.
We are not worried about Israel and its threats," Rafsanjani said when asked about the possibility of the Jewish state launching a pre-emptive strike against Iran's nuclear facilities.
"If Israel committed such an error, we would give it a slap it would never forget -- not only during several years but for all its history," said the powerful ex-president, who now heads Iran's top political arbitration body.
http://quickstart.clari.net/qs_se/webnews/wed/co/Qiran-nuclear-israel.R9ad_DSI.html