In January 2000, US intelligence tracked two suspected Islamic terrorists, Khalid al-Midhar and Nawaf al-Hazmi, to a terror summit of sorts in Kuala Lumpur, Malaysia. Agents knew that at least one of the men - Hazmi - had a visa that would allow him to enter the US.
Unsurprisingly, the CIA wanted both of them followed after they left the meeting and traveled to their next stop, Bangkok.
But the alert to Bangkok agents arrived too late, and the suspects disappeared into the teeming city. Days later the pair flew out unimpeded for Los Angeles. They lived quietly in southern California for more than a year, preparing for an upcoming role: hijackers in the Sept. 11 plot.
Would the worst terror attacks in the nation's history have been prevented if Messrs. Midhar and Hazmi hadn't slipped away in Bangkok? Maybe not. But in hindsight that moment in early 2000, and three others in the summer of 2001 when investigators came close to nailing down their connections with Al Qaeda, were perhaps the closest US intelligence ever came to disrupting Al Qaeda's impending US hits.
Such haunting "what-ifs" haven't necessarily been the focus of the Sept. 11 commission's work. The public hearings that have riveted Washington in recent weeks have instead been aimed at identifying systemic faults in the nation's intelligence apparatus. Commission members are likely to recommend soon some kind of sweeping bureaucratic change - possibly the establishment of a cabinet-level intelligence czar.
But from staff reports and bits of testimony it is possible to piece together a vivid picture of the pre-9/11 struggles of front-line agents against an enemy they only dimly understood. That struggle failed. But seeing how close agents came to thwarting the plot, it is possible to believe that victory is achievable - that another attack is not somehow fated to succeed.
"It is important that the 9/11 commission provide as complete a document as possible," says Jim Walsh, a security expert at Harvard University's Kennedy School of Government. "These are the only people in the US who will ever have the opportunity to see all the documents and hear all the people testify firsthand."
Besides the missteps at the time of the Kuala Lumpur meetings, agents came close to cracking the case three additional times in 2001. After the October 2000 bombing of the USS Cole in Yemen, in which 17 US service members lost their lives, FBI investigators worked with Yemeni officials to identify the culprits.
One of the conspirators of the Cole attack told an FBI investigator in January 2001 that his boss was "Khallad." That name, which means silver in Arabic, was familiar to the FBI investigator. He'd heard about Khallad from another source, who had told both the FBI and CIA that Khallad was close to Osama bin Laden. Khallad's name had also come up during the investigation into the 1998 bombings of the two US embassies in Africa.
The FBI investigator obtained a photograph of the boss and forwarded it to the FBI/CIA joint source, who confirmed that it was indeed Khallad bin Attash, a high-level Al Qaeda operative. As some of this information flowed into the CIA's bin Laden unit in the Counterterrorist Center, its officers began to wonder if Khallad wasn't the same person as Khalid al-Midhar, the possible Al Qaeda operative identified at the 2000 meeting in Kuala Lumpur.
They sent surveillance photos of that January meeting to the same joint source. The source was not able to identify Mr. Midhar, but said he was 90 percent certain the other person in the photos was Khallad bin Attash.
The CIA officers by now realized that Khallad and Midhar were not only different people, but that this higher-up Al Qaeda official and foot soldier were somehow linked. Even though the FBI and CIA used the same source to identify the men in the photos, the agencies did not talk with each other and find a way to fit their separate pieces together.
Besides the lack of communication, there were follow-through issues as well. In May 2001, for example, there was a huge uptick in "chatter," intelligence jargon for intercepted communications warning of an impending attack. A CIA official who had been assigned to work with FBI agents in their international terrorism department began to speculate about where such an Al Qaeda strike might take place.
The 9/11 commission calls this man John. He, too, recalled the January 2000 Kuala Lumpur meeting and decided to plumb the CIA's databases for more information. In mid-May, John and another CIA official examined several agency cables - the reports officers in the field send back to headquarters. He saw that Midhar had a US visa and that Hazmi had arrived in Los Angeles on Jan. 15, 2000.
John then held a lengthy back-and-forth with a CIA analyst to evaluate the cables. John saw the connections between the Khallads and concluded that "something bad was definitely up."
But, according to the report, he focused on Malaysia. This, the staff report concludes, is indicative of the way the two different cultures operate and why it is so difficult for them to marry up. The CIA was focused more broadly on overseas threats, while the FBI was busy trying to build a case against one person.
"The CIA's zone defense concentrated on where, not who," the staff report says. "Had its information been shared with the FBI, a combination of the CIA's zone defense and the FBI's man-to-man approach might have been far more productive."
One final opportunity to impede the 9/11 attackers arose in the summer of 2001. John, the CIA official who'd been detailed to the FBI, asked a counterpart, called Mary, from the FBI who'd been assigned to the CIA to review the Kuala Lumpur material.
Mary began reviewing that cable traffic on July 24. She soon discovered a cable reporting that Midhar, too, had a US visa. A week later she found one reporting that Midhar's visa application listed New York City as his destination. Then, on Aug. 21, she found the March 2000 cable that "noted with interest" that Hazmi had flown to Los Angeles in January 2000. "She grasped the significance of this information," the staff report says.
Mary worked with another FBI analyst on the case, referred to as Jane. Together they met with an immigration official on Aug. 22, who told them that Midhar arrived in the US on Jan. 15, 2000, and again on July 4, 2001. They also learned there was no record that Hazmi had left since January 2001. The two decided that if the men were in the US, they must be found. They divided up the work: Mary worked with the CIA to place the two names on international watch lists, and Jane assumed responsibility for the hunt inside the US. Jane drafted a memo outlining why these two men should be found and questioned by the FBI's field office in New York, and called an agent there to give him a heads up. But her memo wasn't sent until Aug. 28, and it was labeled "routine."
The agents opened a case, but what ensued is tragic. Agents didn't share information because of "the wall" between criminal and intelligence cases.
"The result," the staff report says, "was that criminal agents who were knowledgeable about the Cole and experienced with criminal investigative techniques, including finding suspects and possible criminal charges, were excluded from the search."
The report wraps up the segment on these three missed opportunities with gut-wrenching conclusions. "Both Hazmi and Midhar could have been held for immigration violations or as material witnesses in the Cole bombing case," it concludes. "Investigation or interrogation of these individuals, and their travel and financial activities, also may have yielded evidence of connections to other participants in the 9/11 plot."