Surely if that were true then they would have used them on 9/11. The 737s were utterly shocking but a nuke would have had a far greater effect (greater in damage, NOT goodness, just to clarify).
There are so many stories floating around as to what happened to all of Russias old nukes. Why would Russian nukes end up being sold to the Afghans that totally owned them in battle anyway, nothing adds up.
*ducks under a table and pulls on the foil suit*