When CIA officials subjected their first high-value captive, Abu Zubaida, to waterboarding and other harsh interrogation methods, they ... succeeded in breaking him, and the stories he told of al-Qaeda terrorism plots sent CIA officers around the globe chasing leads. In the end, though, not a single significant plot was foiled as a result of Abu Zubaida's tortured confessions, according to former senior government officials who closely followed the interrogations. Nearly all of the leads attained through the harsh measures quickly evaporated, while most of the useful information from Abu Zubaida -- chiefly names of al-Qaeda members and associates -- was obtained before waterboarding was introduced, they said. Moreover, within weeks of his capture, U.S. officials had gained evidence that made clear they had [falsely accused] Abu Zubaida. Abu Zubaida was not even an official member of al-Qaeda, according to a portrait of the man that emerges from court documents and interviews with current and former intelligence, law enforcement and military sources. Rather, he was a fixer" for radical Muslim ideologues, and he ended up working directly with al-Qaeda only after Sept. 11 -- and that was because the United States stood ready to invade Afghanistan. Since 2006, Senate intelligence committee members have pressed the CIA, in classified briefings, to provide examples of specific leads that were obtained from Abu Zubaida through the use of waterboarding and other methods, according to officials familiar with the requests. The agency provided none, the officials said.