A bunch of national security journalists are tracking down the three Qataris — described as a potential fifth 9/11 cell — described in this WikiLeaks cable and first reported by the Telegraph. I wanted to do the reverse of what they’re doing — to use their reporting to see how someone gets on a terrorist watchlist.

The cable, written by our Embassy in Qatar, recommends that Mohamed Ali Mohamed al Dahham al Mansoori, a UAE citizen, be added to the National Counterterrorism Center watchlist. It bases that recommendation on what it calls an “ongoing” FBI investigation into whether Mansoori helped three Qataris, who in turn are suspected of either conducting surveillance of 9/11 targets or of preparing to join the attack, only to leave the country on September 10 instead. While the cable provides specific details about the three Qataris — including that their tickets were arranged by an unnamed “convicted terrorist” — it explains the tie to al Mansoori simply,”that the men spent a week with Mr. al Mansoori traveling to different destinations in California.”

The explanation raises some questions about the watchlisting process. That our Embassy in Qatar — not the FBI with its reported ongoing investigation, not our embassy in Abu Dhabi — would be placing someone on the terrorist watchlist eight years and five months after 9/11 is rather curious.

Particularly given reports that the FBI pursued the leads on the Qataris and Mansoori and ultimately could find no direct tie with 9/11.

Philip Zelikow says the 9/11 Commission was aware of a similar lead, but never proved a tie with 9/11.

In 2004, the commission did not have information reliably linking these people to the 9/11 plot. As best we can remember, we were aware of a lead with some of these elements.  At that time it had been further investigated and, from what we could learn, it had not panned out.

The FBI (perhaps a little sensitive about the possibility they may have missed something earlier) claims the cable is not accurate.

The cable, the FBI official said, was not accurate. “They’re not sought by us and they’re not 9/11 plotters,” the FBI official said, speaking anonymously so he could speak candidly.

But the FBI source must mean the report of an ongoing FBI investigation is inaccurate. Like Philip Zelikow, this source says the content of this cable was investigated but dismissed.

The man named in the cable, Mohamed ali Mohamed al-Dahham al-Mansoori, was indeed investigated in the wake of the 2001 attacks, but after interviewing him, the FBI eventually decided that he did not play any role in the plotting. Officials remained concerned, however, that he might be a future threat to the US and revoked his visa and deported him.

That said, the FBI source did admit that Mansoori and the Qataris have come back on the radar.

However, while the FBI did interview al-Mansoori, according to this FBI official, the Qatari men were never located after 9/11. Thus the FBI kept an unofficial “tickler” on the men in case they ever surfaced. A year ago, the official said, there was unspecified intelligence that led Doha authorities to believe that Mansoori might surface along with the three other men. That intelligence is what triggered the February 2010 cable, the official said, adding, “Would it be nice to sit down and look them in the eye and ask them about their involvement? Sure. But we ran it to ground and the information we collected is probably more reliable than what they’d tell us anyway.”

At first I wondered whether the watchlist might be tied to new intelligence on the “convicted terrorist” mentioned in the cable. But Michael Isikoff makes a compelling argument the “convicted terrorist” is the brother of one of the three Qataris, who was convicted of visa fraud and expelled in 2003.

News reports in 2002 and 2003 identified a Qatari terror suspect who lived in Chesapeake, Va. Fahed Alhajri, a sportscaster for Qatari television who left the country in 2003 after being convicted in a student visa fraud scheme. Alhajri, who initially aroused suspicion when he was discovered to have had photos of Osama bin Laden and the World Trade Center in his apartment, as well as a datebook with only one entry — on Sept. 11.

So it seems that the story behind the cable is that after 9/11, these Qataris, one of their brothers, and Mansoori all raised suspicions that did not, however, tie them directly to 9/11, but were enough to get Alhajri and Mansoori expelled from the US. And then last year, when a report surfaced, in Doha, about the Qataris, authorities recalled that Mansoori had had some tie to them.

Which leaves the unexplained one year delay between the time the Qataris surfaced again last year and this cable. But there is a perfectly plausible explanation for why Doha, a year after the report on the Qataris, would make a “priority” request to put Mansoori on the watchlist: the UndieBomber.

As you recall, the UndieBomber was placed in a terrorism database based on his father’s concerns about his radicalization, but he was not placed on the watch list because, “there was ‘insufficient derogatory information available’ to include him.” Once that was discovered, there was a whole lot of scrutiny into the standards used to place people on watchlists. And while I can’t prove it, I would bet that everyone went back and reevaluated the people with suspected ties to extremists for whom there had previously been judged to be insufficient information against them to watchlist (I’m guessing the Qataris had already been watchlisted, but not Mansoori). That is, I’m guessing the timing of this has more to do with the UndieBomber than any ongoing investigation.