At last, a common thread between the two catastrophic security breaches at the end of the year. Both plots involved a jihadi who’d supposedly been “reformed.” Emphasis on “supposedly.”

According to Western intelligence officials, the perpetrator was Humam Khalil Abu-Mulal al-Balawi, 36, an al-Qaida sympathizer from the town of Zarqa, which is also the hometown of Abu Musab al-Zarqawi, the Jordanian militant Islamist responsible for several devastating attacks in Iraq.

Al-Balawi was arrested by Jordanian intelligence more than a year ago. However, the Jordanians believed that al-Balawi had been successfully reformed and brought over to the American and Jordanian side, setting him up as an agent and sending him off to Afghanistan and Pakistan to infiltrate al-Qaida.

How’d he get so many top CIA agents within blast range? Easy — he claimed he had urgent information about Ayman al-Zawahiri.

The former senior intelligence official said one of the big unanswered questions is why so many people were present for the debriefing — the interview of the source — when the explosive was detonated.

A half-dozen former CIA officers told The Associated Press that in most cases, only one or two agency officers would typically meet with a possible informant along with an interpreter. Such small meetings would normally be used to limit the danger and the possible exposure of the identities of both officers and informants.

An online jihadist magazine in September 2009 posted an interview with al-Balawi, according to SITE Monitoring Service, a terrorist watch group that reads and translates messages on extremist forums.

Three questions. One: Did they think he was operating under deep cover when he gave that interview in September 2009 or did they not recognize the pseudonym he used (“Khorsani”) when they presumably saw it? Two: Why did al-Balawi lure the agents with info on Zawahiri instead of Bin Laden? Presumably the latter would have attracted an even bigger audience, no? Third: What role, precisely, did Sharif Ali bin Zeid, the Jordanian intel agent who recruited al-Balawi and drove him to the base in Khost — only to be killed in the ensuing explosion — play in this? I don’t mean to impugn the guy: WaPo had a story just this morning about how useful Jordanian intelligence has been to us in the war on terror, and bin Zeid himself was a relative of Jordanian King Abdullah. He was probably as innocent a victim as any of the CIA casualties. But he was also the contact for a double agent, and it still hasn’t been explained how al-Balawi made it into the meeting without once being searched on the base. Was it a joint suicide mission or did bin Zeid himself die a hero’s death in service to the west’s cause by trusting al-Balawi too much?

Update: Al-Balawi might not have been blowing smoke about Zawahiri: “It is now thought that he was sent on his suicide mission by Mr al-Zawahiri himself.”