I am not saying Israel should attack Iran, but if Iran gains nuclear weapons, and their government has repeated many times they want to wipe Israel off the map, it stands to reasonable logic that Iran will wipe Israel off the map if it gains nuclear weapons. By that threat Israel may see it as in their best interests to wipe Iran off the map first in a pre-emptive nuclear strike.
Remember, MAD doesn't apply to Islam because of the whole Martyrdom belief. Islamic extremists, which practically runs Iran and its military, believe that if they die in the name of Allah and destroys His enemies the extremist would gain a seat in Heaven and 72 virgins.
What I wonder is if the Koran specifically states these virgins are female or is that just assumed.