What we all need at the moment is a good 9/11 conspiracy theory to blow away the winter cobwebs:
  https://www.zerohedge.com/news/2018-09-03/did-cia-saudi-arabia-conspire-keep-911-details-secret

“The authors of a new book on 9/11 hope to refocus public attention on the cover-up. Thoroughly mining the multiple official investigations into the event, John Duffy and Ray Nowosielski find huge holes and contradictions in the official story that 9/11 was merely “a failure to connect the dots.” Duffy, a left-leaning writer and environmental activist, and Nowosielski, a documentary filmmaker, have nowhere near the prominence of other journalists who have poked holes in the official story, in particular Lawrence Wright, author of The Looming Tower: Al-Qaeda and the Road to 9/11, the Pulitzer Prize–winning book that was turned into a gripping multi-part docudrama on Hulu earlier this year. But Duffy and Nowosielski come to the story with a noteworthy credential: In 2009 they scored an astounding video interview with Richard Clarke, a White House counterterrorism adviser during the Bill Clinton and George W. Bush administrations. In it, Clarke raged that top CIA officials, including director George Tenet, had withheld crucial information from him about Al-Qaeda’s plotting and movements, including the arrival in the U.S. of future hijackers Khalid al-Mihdhar and Nawaf al-Hazmi. In The Watchdogs Didn’t Bark: The CIA, NSA, and the Crimes of the War on Terror, the authors assemble a compelling case of a government-wide cover-up of Saudi complicity in the affair.

In 2002, Tenet swore to Congress that he wasn’t aware of the imminent threat because it came in a cable that wasn’t marked urgent—and “no one read it.” But his story was shredded five years later when Senators Ron Wyden and Kit Bond forced loose an executive summary of the CIA’s own internal investigation of 9/11, which stated that “some 50 to 60 individuals read one or more of the six Agency cables containing travel information related to these terrorists.” Clarke went ballistic. Until then, he had trusted Tenet, a close colleague and friend, to tell the truth. In 2009, despairing at the lack of media traction on the astounding disclosure, he wrote a book about the duplicity, Your Government Failed You, which was largely ignored. So when Duffy and Nowosielski came calling, he welcomed them. “I believed, for the longest time, that this was one or two low-level desk officers who got this [information about Hazmi and Mihdhar] and somehow didn’t realize the significance,” he told them. But “50—five oh—50 CIA officers knew this, and they included [Tenet and] all kinds of people who were regularly talking to me? Saying I’m pissed doesn’t begin to describe it.”

All these years later, it’s still unclear why the CIA would keep such crucial details about Al-Qaeda movements from the FBI. Clarke and other insiders suspect that the spy agency had a deeply compartmented plan in the works to recruit Hazmi, Mihdhar and perhaps other Al-Qaeda operatives as double agents. If the FBI discovered they were in California, the theory goes, it would have demanded their arrest. When the CIA’s recruitment ploy fizzled, Tenet and company hid the details from Clarke lest they be accused of “malfeasance and misfeasance,” he said. It’s the only logical explanation for why the presence of Hazmi and Mihdhar was kept from him until after the attacks, Clarke said. “They told us everything—except this,” he says in the video. Tenet and two of his counterterrorism deputies, Rich Blee and Cofer Black, issued a statement calling Clarke’s theory “reckless and profoundly wrong.” But now Clarke has company. Duffy and Nowosielski found other key former FBI counterterrorism agents and officials who have developed deep doubts about Tenet’s story. The only element they disagree on is which officials were responsible for the alleged subterfuge.

“I think if there were some conscious effort” not to tell the bureau what was going on, Dale Watson, a former FBI deputy chief of counterterrorism told them, “it was probably” carried out below Tenet, Blee and Black, by managers of the CIA’s Osama bin Laden unit. But Pat D’Amuro, an even more senior former FBI counterterrorism official, told them, “There’s no doubt in my mind that [withholding the information] went up further in the agency” than those managers. “And why they didn’t send it over, to this day, I don’t know why.”

     Well, from all of this, the great “why” must be that there was some interest served in having the buildings blown up. It justified the “war on terror,” which really began the real war of terror in retaliation. And, the rest is history, that we and Europe are now unfortunately living through:
  https://www.youtube.com/watch?v=s04VUk_41r8 
  https://www.youtube.com/watch?v=djKIlXz8WJs 
  https://www.youtube.com/watch?v=i6eMq5Rit1w