A new book by Gerald Posner makes startling allegations that captured Al Qaeda leader Abu Zubaydah revealed details of direct connections between the highest levels of the Saudi royal family, Pakistan’s ISI, and Osama bin Laden and Al Qaeda: Confessions of a Terrorist. (Hat tip: Doss.)

Posner elaborates in startling detail how U.S. interrogators used drugs—an unnamed “quick-on, quick-off” painkiller and Sodium Pentothal, the old movie truth serum—in a chemical version of reward and punishment to make Abu Zubaydah talk. When questioning stalled, according to Posner, cia men flew Zubaydah to an Afghan complex fitted out as a fake Saudi jail chamber, where “two Arab-Americans, now with Special Forces,” pretending to be Saudi inquisitors, used drugs and threats to scare him into more confessions.

Yet when Zubaydah was confronted by the false Saudis, writes Posner, “his reaction was not fear, but utter relief.” Happy to see them, he reeled off telephone numbers for a senior member of the royal family who would, said Zubaydah, “tell you what to do.” The man at the other end would be Prince Ahmed bin Salman bin Abdul Aziz, a Westernized nephew of King Fahd’s and a publisher better known as a racehorse  owner. His horse War Emblem won the Kentucky Derby in 2002. To the amazement of the U.S., the numbers proved valid. When the fake inquisitors accused Zubaydah of lying, he responded with a 10-minute monologue laying out the Saudi-Pakistani-bin Laden triangle.

Zubaydah, writes Posner, said the Saudi connection ran through Prince Turki al-Faisal bin Abdul Aziz, the kingdom’s longtime intelligence chief. Zubaydah said bin Laden “personally” told him of a 1991 meeting at which Turki agreed to let bin Laden leave Saudi Arabia and to provide him with secret funds as long as al-Qaeda refrained from promoting jihad in the kingdom. The Pakistani contact, high-ranking air force officer Mushaf Ali Mir, entered the equation, Zubaydah said, at a 1996 meeting in Pakistan also attended by Zubaydah. Bin Laden struck a deal with Mir, then in the military but tied closely to Islamists in Pakistan’s Inter-Services Intelligence (isi), to get protection, arms and supplies for al-Qaeda. Zubaydah told interrogators bin Laden said the arrangement was “blessed by the Saudis.”

Zubaydah said he attended a third meeting in Kandahar in 1998 with Turki, senior isi agents and Taliban officials. There Turki promised, writes Posner, that “more Saudi aid would flow to the Taliban, and the Saudis would never ask for bin Laden’s extradition, so long as al-Qaeda kept its long-standing promise to direct fundamentalism away from the kingdom.” In Posner’s stark judgment, the Saudis “effectively had (bin Laden) on their payroll since the start of the decade.” Zubaydah told the interrogators that the Saudis regularly sent the funds through three royal-prince intermediaries he named.