Now if I were inclined toward a conspiratorial view of the world, I would speculate that the very outlandishness of these claims is itself part of a conspiracy to obscure what really happened on 9/11. This meta-conspiracy theory would go something like this: Over the past 11 years, it has slowly but inexorably become clear that the CIA uncovered key details of the 9/11 plot several months in advance, and tried on numerous occasions to get the Bush administration to take action to stop it.

The US government shut down a series of court cases arising from a multimillion pound business dispute in order to conceal evidence of a damning intelligence failure shortly before the 9/11 attacks, MPs were told.

Moreover, the UK government is now seeking similar powers that could be used to prevent evidence of illegal acts and embarrassing failures from emerging in court, David Davis, the former shadow home secretary, told the Commons.

Former Florida Sen. Bob Graham, who co-chaired Congress’ Joint Inquiry into the 9/11 terrorist attacks, has seen two classified FBI documents that he says are at odds with the bureau’s public statements that there was no connection between the hijackers and Saudis then living in Sarasota, Fla.

“There are significant inconsistencies between the public statements of the FBI in September and what I read in the classified documents,” Graham said.

The Los Angeles Times examines the staggering sums of money expended on patently absurd domestic “homeland security” projects: $75 billion per year for things such as a Zodiac boat with side-scan sonar to respond to a potential attack on a lake in tiny Keith County, Nebraska, and hundreds of “9-ton BearCat armored vehicles, complete with turret” to guard against things like an attack on DreamWorks in Los Angeles.