Did Waterboarding Lead to bin Laden's Death?

The short answer: We don't know for sure.

For years, U.S. intelligence officials collected bits of data on the courier who ultimately led them to Osama bin Laden's compound in Abbottabad, Pakistan, initially from detainees at CIA black sites, during a time when U.S. interrogators are known to have used harsh tactics such as waterboarding. More information was obtained later, after President Obama ended the Bush-era interrogation tactics.

White House Press Secretary Jay Carney did answer yes or no when he was asked, at Tuesday's press briefing, whether harsh interrogations yielded relevant intelligence:

Q Were any results of such techniques used in helping to track down bin Laden?

MR. CARNEY: Mark, the fact is that no single piece of information led to the successful mission that occurred on Sunday, and multiple detainees provided insights into the networks of people who might have been close to bin Laden. But reporting from detainees was just a slice of the information that has been gathered by incredibly diligent professionals over the years in the intelligence community. And it's simply strange credulity to suggest that a piece of information that may or may not have been gathered eight years ago somehow directly led to a successful mission on Sunday. That's just not the case.

Earlier on Tuesday, Senate Intelligence Committee Chairwoman Diane Feinstein (D-Calif.) said that as far as she knows, none of the information had come from harsh interrogations. But she also said she didn't know exactly where all of it had come from. The committee's Democratic staff is currently engaged in a broader study of harsh interrogation tactics, and Feinstein's background knowledge seems to be informed by that investigation.

"To the best of our knowledge, based on a look, none of it came as a result of harsh interrogation practices," Feinstein said today at a press conference.

Feinstein also said, the first time she was asked about it at the press conference:

We are in the process of a big study of the detention and interrogation of the detainees, on the Intelligence Committee ... [committee staff] have gone through three million emails, cables, pieces of paper, looking for this. To date, the answer to your question is no, nothing has been found to indicate that this came out of Guantanamo, and people were questioned, but there were no positive answers as to the identity of the courier. ... I do not know exactly where the information came from.

The Associated Press, which outlined the trail of intelligence in this story, noted that Khalid Sheikh Mohammed, who admitted to knowing the courier by his nom de guerre, did not do so while being waterboarded:

Mohanmmed did not discuss al-Kuwaiti while being subjected to the simulated drowning technique known as waterboarding, former officials said. He acknowledged knowing him many months later during standard interrogations.

But there were many steps in the chain to courier Sheik Abu Ahmed, known to al Qaeda operatives as Abu Ahmed al-Kuwaiti.

Here's how the AP explained the trail. Detainees in CIA black-site prisons told interrogators of al-Kuwaiti shortly after September 11, 2001; Khalid Sheikh Mohammed confirmed knowing al-Kuwaiti but denied having anything to do with him; another top al Qaeda operative, Hassan Ghul, identified that al-Kuwaiti was a courier; Faraj al Libi, who replaced Mohammad in al Qaeda's command, told CIA interrogators after his capture that he had received his new assignment via courier and denied knowing al-Kuwaiti so forcefully that U.S. intelligence officials suspected he and KSM were protecting the courier; the CIA eventually, after years of work, identified al-Kuwaiti by his real name.

We'll find out at some point how thoroughly Feinstein's staff has examined each link in this chain, as part of its investigation into harsh interrogation tactics.

In the meantime, it seems possible that, at one of those points, harsh interrogation tactics could have been used -- particularly in the CIA black sites -- although Feinstein's staff is presumably familiar with how KSM, Ghul, and Libi were handled. The senator seems intent on getting to the bottom of it, and more information will probably come out as her staff continues its investigation and as reporters keep asking questions.

As Carney said, there were a lot of data points that led to U.S. intelligence officials to ultimately locate Osama bin Laden. Another possibility is this: There were so many pieces of intelligence, obtained across two administrations and under very different policies of detainee treatment, that no one's completely sure whether harsh interrogation tactics yielded certain scraps.