A few months ago he was the operational chief, a.k.a. the number three, which means his life expectancy was roughly the same as one of Spinal Tap’s drummers. Then Bin Laden took a bullet in the face and he moved up to number two, which worked out okay for the guy who previously held that rank. Oh well. Things change.

He’s not a glamour-puss like Zawahiri so you may not know the name, but this guy is a very big deal. Or rather, was:

A U.S. official, who spoke on condition of anonymity to summarize the government’s intelligence on [Atiyah Abd] al-Rahman, said al-Rahman’s death will make it harder for Zawahiri to oversee what is considered an increasingly weakened organization.

“Zawahiri needed Atiyah’s experience and connections to help manage al-Qaida,” the official said.

Al-Rahman was killed Aug. 22 in the lawless Pakistani tribal region of Waziristan, according to a senior administration who also insisted on anonymity to discuss intelligence issues.

The official would not say how al-Rahman was killed. But his death came on the same day that a CIA drone strike was reported in Waziristan.

Here’s an account of the August 22 drone strike from the Pakistani newspaper Dawn. Two missiles were fired, one hitting a car carrying at least four suspected jihadis and the other hitting a house. Bill Roggio noted at the time that the site of the strike is in the Mir Ali area of Waziristan, which is basically Thunderdome for aspiring terrorists. The Taliban and the Haqqani network operate there, and according to some jihadi sources, hundreds upon hundreds of suicide bombers have trained at local camps. Roggio also calls it “a known hub for al Qaeda’s military and external operations councils,” which would explain Rahman’s presence and why a drone strike would be necessary rather than a special ops raid a la Osama. Not only is the target moving around frequently, but in a place crawling with heavily armed mujahedeen, things could get hairy quickly for a small band of U.S. troops who ended up trapped there.

So who was he? He was someone who wanted to kill you and had been working hard for ages to figure out how:

A U.S. official told CBS News al-Rahman spoke on behalf of both Osama bin Laden and Ayman Mohammed Rabie al-Zawahiri, and was the one affiliates “knew and trusted.”

“There’s no question this is a major blow to al Qaeda,” the official told CBS News Homeland Security correspondent Bob Orr. “Atiyah was at the top of al Qaeda’s trusted core. He ran daily operations for the group since Shaykh Sa’id al-Masri was killed last year, and has been Zawahiri’s second-in-command since Bin Laden’s death in May.”

“He planned the details of al Qaeda operations and its propaganda,” the official told CBS News. “His combination of background, experience, and abilities are unique in al Qaeda – without question, they will not be easily replaced.

Brian Fishman of the Combating Terrorism Center at West Point calls Rahman the communications glue of the organization and says that losing him will damage AQ as much as losing Bin Laden did. If you doubt him, take 30 seconds to re-read this post from last month. Rahman was so important that Bin Laden appointed him as the group’s official emissary in Iran, which allowed him to arrange transit through the country for AQ operatives. Rahman was also Bin Laden’s point man on a plot to attack the United States on the anniversary of 9/11 this year, which is all you need to know about how far his ambitions extended. This was not a guy who operated locally only, against U.S. troops in Afghanistan. He was thinking big. And judging by how frequently he communicated with Osama, he was clearly someone for whom the group had high hopes. Says Steve Hayes at the Standard, “If Atiyah Rahman is indeed dead, as it appears, [it’s] hard to overstate how significant a blow that is for AQ. And win for us.” Indeed.

Three things to watch going forward. One: What happens now to Al Qaeda’s relationship with Iran? The Iranian leadership trusted Rahman enough to deal with him; that may not be true of the next emissary. Two: How exactly did we find this guy? It’d be superb if something recovered by the SEALs from Bin Laden’s compound led us to him, but no one’s confirming that — yet. Three: How long now before we find Zawahiri? Rahman must have been in touch with him, if only because Zawahiri would want to leverage Rahman’s relationships with the rank and file to shore up his own credibility as the new number one. (Zawahiri is famously disliked by many jihadis and can’t rule by charisma the way Bin Laden could. He needs institutional support among the top players to keep a grip on the group.) If we got a hot tip on where to find Rahman, the tipster might very well have a hot tip on where to find the new top dog too. Here’s hoping.