A nuclear strike on America. Perhaps 100,000+ deaths.
And Iran won't even seem to be responsible. They'll just have some suicidal/homocidal muslim maniacs carry out their dirty work. There will be no obvious target to strike back at.
Having a nuclear weapon puts Iran on the front row at any meetings of world powers, and that is their goal.
The NEW WORLD ORDER is planning to consolidate all assets, then divvy up the take. One must be on the front row to get their 'say'. Having that Ace card up your sleeve (nuclear weapons) is what keeps the other world leaders (gangsters) from shooting you in the head and taking your stuff.