This is one aspect that gives me second thoughts. Although Musharrif has probably kept the lid on it for his part (why give the bomb to those who've tried to assinate you several times), Khan (the mad scientist) is another issue.
If you choose not to believe Paul Williams, that's ok. I don't know what to believe about his claims. I do know that his claims are feasible. Enriched materials are available to anyone with the bux. The bomb is available to anyone with a lathe and a drill press.
Is Williams the one who wrote that AQ obtained soviet suitcase nukes? If so feasible, possibly, however there are at least three parallel stories out there (Soviet Mafia, KGB and Chechens). The next strike (or if we are able to stop it in time) will tell all.
A quick quote from p. 260 of Kluckhohn's 1962 book The Naked Rise of Communism
Business in Britain, Canada and the United States and other free nations must realize that it is trading to destroy itself. In any case, the U.S. government should halt all trade with the Soviet Union, Red China and the Red satellite nations. We can politely and firmly tell our Allies that they will get no help from us, and no backing, if they do not cease this trading. Our poor diplomatic poker players have been euchred into making one concessoin after another on industrial trade items and, in their eagerness to please, are prepared to make more the moment no one is looking.The story is told that two Russian Communists were talking. "The United States?" said one, "Bah! We have 10,000 little nuclear bombs. We put them in suitcases and carry them into the United States. And poof, we blow it up." "Wonderful," said the other Russian, "Why aren't we doing it?" "Because," was the mournful reply, "we don't have the suitcases."