Enemies do not attack their allies.
Oh, it would have happened, IMHO. Clinton, particularly, is the epitomy of evil to OBL, from what I've read. Only, there would be no war on terrorism in defense of the U.S. - it would go like this:
Janet Reno (or one like her) would come out after a day or two in a press conference and say, "I cannot comment publicly on an on-going investigation." Then, a week later, 2 guys would be arrested - put in prison - then, more than likely, be pardoned after a year or two.