Just so much Magpie chatter - He won't do it because he can't do it without the willing assistance of Saudi Arabia and Turkey. In the current situation this assistance will not be forthcoming. My bet is that the inspectors will go back in and some face-saving way of backing down will be found.

As to the potential nuclear threat and means of delivery, Alanabit and Bobert are thinking of conventional means of delivery, Doug R and Amos have pointed out how it could be done. A device could be assembled bit by bit over a number of years (The investigations into the WTC attack have established that it was three years plus in the planning stage). As a result of that attack, the intelligence, customs and law enforcement services of a great many countries are aware and working to prevent any such attempt - Good luck to them.