To their surprise, Zubaydah didn't display fear, but relief. While previously he hadn't even been willing to reveal his identity, he now gave his name, said he was happy to see them, and asked the interrogators to call a senior member of the Saudi royal family, for whom he provided private home and cell phone numbers from memory. That man was Prince Ahmed bin Salman bin Abdul-Aziz, a nephew of King Fahd, owner of the Research and Marketing Group, and owner of the Kentucky Derby winning horse War Emblem.
Zubaydah claimed that bin Laden had made a cooperative arrangement with Pakistani air force chief Air Marshal Mushaf Ali Mir, a military official with close ties to the pro-Islamist members of ISI, the Pakistani intelligence agency, and that this arrangement had the blessing of Prince Turki of Saudi Arabia. Also according to Zubaydah, Turki had made a deal to provide aid to the Taliban in Afghanistan and would not ask for extradition of bin Laden, so long as his activities were directed away from Saudi Arabia.
Zubaydah also implicated Prince Sultan bin Faisal bin Turki al-Saud and Prince Fahd bin Turki bin Saud al-Kabir as supporters of al Qaeda, and stated that Mir and Prince Ahmed had advance knowledge that there would be terrorist attacks against the U.S. on 9/11.
His interrogators were skeptical of his claims, even though information from him was successfully used to capture Omar al-Faruq, a senior al Qaeda operative in Southeast Asia. And when U.S. personnel (not posing as Saudis) confronted Zubaydah about his claims, he denied it all and said that he had made it up. CIA investigation of his claims found nothing to refute them, however, and some corroborating evidence. A report on his claims was submitted to Pakistan and Saudi Arabia, each of which responded that the claims were entirely false.
On July 22, 2002, Prince Ahmed died unexpectedly of a heart attack at the age of 43, and on July 23, 2002, Prince Sultan bin Faisal bin Turki al-Saud was killed in a car accident at the age of 41. A week later, Prince Fahd bin Turki bin Saud al-Kabir was found dead, having "died of thirst" at the age of 25. Prince Turki was fired from his position as head of Saudi Intelligence on September 1, 2001, and became the Saudi ambassador to Great Britain in 2002.
On February 20, 2003, Pakistani air force chief Mir, his wife, and fifteen others were killed in a plane crash.
None of this appeared in the 9/11 Commission Report, though it might have been planned for that document. This is because the Bush administration censored 28 pages of material about Saudi connections to 9/11 from the report on the grounds of national security.
In 2004, the former chairman of the Senate Intelligence Committee, Sen. Bob Graham, published a book, Intelligence Matters: The CIA, the FBI, Saudi Arabia, and the Failure of America's War on Terror, in which he claimed that Bush covered up evidence that the Saudi government was aiding at least two of the 9/11 hijackers via Omar al-Bayoumi, which Graham discussed in an interview with Salon.com.
More recently, New York Times reporter Philip Shenon's book, The Commission: The Uncensored History of the 9/11 Investigation, raises the same point about the Saudi government's ties to Omar al-Bayoumi.
I think the full story of Saudi and Pakistani involvement in 9/11 has yet to be told.
None of this involves munitions used to collapse buildings, unmanned drones, missiles hitting the Pentagon, or the innocence of Osama bin Laden, like the crazy 9/11 truth movement's claims. It does involve U.S. political relations with nations that have been key allies in the war on terror, both of which have governments which have been close to collapse, and one of which (Pakistan) is a nuclear power and one of which is the source of most foreign oil imported by the U.S. It's clear why the U.S. would treat relations with these countries gingerly even if they did have members of their governments directly involved in 9/11, and why those countries would want to quietly dispose of the problem.
UPDATE (July 16, 2009): Greetings to Talking Points Memo readers, here because of a link in the comments from a story about a Bush/Cheney CIA assassination program apparently permitted to operate domestically. That commenter seemed to suggest that the CIA might have been behind the deaths described in the above post, which I think is highly unlikely in comparison to the speculation that the Saudis themselves might have taken care of matters.
UPDATE (April 13, 2015): Zacarias Moussaoui, the 20th hijacker, claimed in February 2015 that members of the Saudi royal family helped fund the 9/11 attacks. He specifically named Prince Turki al-Faisal Al Saud and Prince Bandar bin Sultan.