Of course, "Zero Dark Thirty" can't address in 2½ hours the whole complex tale of the CIA interrogation program, but an important strand of that tale is missing from the film.

FBI officials were adamantly opposed to the use of coercive techniques by the CIA on al Qaeda detainees because they deemed them both unethical and counterproductive. An FBI official noted that after his abusive interrogations by the CIA, al-Qahtani began "evidencing behavior consistent with extreme psychological trauma (talking to non-existent people, reporting hearing voices, crouching in a cell covered with a sheet for hours on end.)"

And the story of Abu Zubaydah, the first prisoner to be placed in a secret overseas CIA prison, is an instructive counterargument to the idea that coercive interrogations are the best way to get useful information out of terrorists and is a tale that does not appear in "Zero Dark Thirty."

Abu Zubaydah was first interrogated by Ali Soufan, one of the few Arabic-speaking FBI agents. Soufan softened up Abu Zubaydah by calling him "Hani," the childhood nickname his mother had used for him, a fact that the FBI agent had gathered from intelligence files. The approach started yielding quick results.

When Abu Zubaydah was shown a series of photos of al Qaeda members by Soufan, he identified one of them as the operational commander of 9/11, Khalid Sheikh Mohammed. Abu Zubaydah's confirmation of Mohammed's role in 9/11 was the single most important piece of information uncovered about al Qaeda after the attacks on the Trade Center and Pentagon, and it was discovered during the course of a standard interrogation, without recourse to any form of coercion. Soufan recalled that Abu Zubaydah gave up the information about a week or so into his interrogation.

Abu Zubaydah was later waterboarded 83 times by the CIA. This form of simulated drowning is generally considered torture, but none of it produced much in the way of useful information. In the end, the multiple waterboardings of Abu Zubaydah provided no specific leads on any plots, although clearly his role as an al Qaeda logistician did give him insights into the organization and its personnel.

Eight years more

And were interrogations of al Qaeda detainees anyway really the key to how bin Laden was ultimately found? After all, it still took another eight years after the interrogation of the 20th hijacker, al-Qahtani, to find bin Laden.

Indeed, there were a number of key breaks during those eight years that had nothing to do with the interrogations of al Qaeda detainees. A large break, according to U.S. counterterrorism officials, came in 2007, when a foreign intelligence service that they won't identify told the CIA that the Kuwaiti's real name was Ibrahim Saeed Ahmed.

This lead seems very likely to have come from the Pakistanis given the fact that "the Kuwaiti" was, in fact, a Pakistani whose family had settled in Kuwait and who from 2002 onward was back living in Pakistan. (In "Zero Dark Thirty," the break about identifying the Kuwaiti's real name is explained as coming from Morocco's intelligence service.)

It would still take three more years for the CIA to find Ibrahim Saeed Ahmed in Pakistan, a country with a population of 180 million people. This involved painstaking work going through reams of phone conversations to try to locate him through his family and circle of associates.

In June 2010, the Kuwaiti and his brother both made changes in the way they communicated on cell phones that suddenly opened up the possibility of the "geolocation" of both their phones, according to U.S. counterterrorism officials.

Finally, sometime in the late summer of 2010, the Kuwaiti received a call from an old friend in the Gulf, a man whom U.S. intelligence officials were monitoring. "We've missed you. Where have you been?" asked the friend. The Kuwaiti responded elliptically. "I'm back with the people I was with before." There was a tense pause in the conversation as the friend mulled over that response. Likely realizing that the Kuwaiti was back in bin Laden's inner circle, the caller replied after some hesitation, "May God facilitate."

The CIA took this call as a confirmation that the Kuwaiti was still working with al Qaeda, a matter that officials were still not entirely sure about.

The National Security Agency was listening to this exchange and through geolocation technologies was able to zero in on the Kuwaiti's cell phone in northwestern Pakistan. But the Kuwaiti practiced rigorous operational security and was always careful to insert the battery in his phone and turn it on only when he was at least an hour's drive away from the Abbottabad compound where he and bin Laden were living. To find out where the Kuwaiti lived by monitoring his cell phone would only go so far.

In August 2010, a Pakistani "asset" working for the CIA tracked the Kuwaiti to the crowded city of Peshawar, where bin Laden had founded al Qaeda more than two decades earlier. In the years when bin Laden was residing in the Abbottabad compound, the Kuwaiti would regularly transit though Peshawar, as it is the gateway to the Pakistani tribal regions where al Qaeda had regrouped in the years after 9/11.

Once the CIA asset had identified the Kuwaiti's distinctive white Suzuki SUV with a spare tire on its back in Peshawar, the CIA was able to follow him as he drove home to Abbottabad, more than two hours drive to the east.

The large compound where the Kuwaiti finally alighted immediately drew interest at the agency because it didn't have phone or Internet service, which implied its owners wanted to stay off the grid. Soon, some CIA officials would come to believe that bin Laden himself was living there.

Every form of intelligence-gathering

The sequence of events that led the CIA to bin Laden involved first interrogations that surfaced the alias of bin Laden's courier. That was then followed by key information coming from a "liaison" relationship with a foreign intelligence service that supplied the real name of the courier, which was then followed by U.S. signals intelligence (known as SIGINT) that tracked the courier's phone to a particular city in Pakistan and finally human intelligence ("HUMINT," CIA spies on the ground) who tracked the courier to Abbottabad.