The rumors began almost at once.

It was 10:06 a.m. on September 11, 2001, when United Airlines' Flight 93 -- the last of the four hijacked jets -- plowed into a field in rural Pennsylvania. Within hours the coffeehouses of the Arab world were abuzz with speculation that the attacks were the work of the Israeli intelligence service, the Mossad. At the same time, former CIA Director James Woolsey, an exemplar of American neoconservatism, was already claiming that Baghdad was behind the attacks.

Such fantasies persist, even today.