A second American citizen who died in the air strike that killed radical cleric Anwar al-Awlaki was the driving force behind al-Qaida's English-language magazine.
Samir Khan, 25, was among the five people with Awlaki before a US drone hit a convoy which the leader was joining, according to US and Yemeni officials.
Khan, a US citizen from North Carolina with a Pakistani background, was the man behind Inspire, which offered a heady mix of Qur'anic commentary, propaganda and tips on bomb-making and encryption to aspiring jihadis.
Since its launch in June 2010, seven issues of the magazine have been released, but publication has been far from smooth. British intelligence officers hacked into an early edition, inserting a pdf file containing fairy cake recipes and garbling most of the magazine's 67 pages.
Documents seized following the death of Osama bin Laden in May reveal that the al-Qaida chief had angrily vetoed a plot suggested by the magazine, in which rotating blades would be fitted to a tractor to "mow down the enemies of Allah". US officials said that Bin Laden had slapped down the plan on the grounds that it would create "indiscriminate slaughter".
This week an article in the magazine called on the Iranian president, Mahmoud Ahmadinejad, to stop spreading conspiracy theories about the 9/11 attacks.
The article attacked Ahmadinejad for discrediting al-Qaida of carrying out the attacks and described the recent remarks during his UN general assembly speech as ridiculous.
Last week in New York, Ahmadinejad questioned the US version of 11 September events and cast doubt on motives behind the decision to dispose of the dead body of Osama bin Laden at sea.
The al-Qaida article insisted it had been behind the attacks and criticised the Iranian president for discrediting the terrorist group.
"For them, al-Qaida was a competitor for the hearts and minds of the disenfranchised Muslims around the world," said the article. "Al-Qaida … succeeded in what Iran couldn't. Therefore it was necessary for the Iranians to discredit 9/11, and what better way to do so? Conspiracy theories."
In an apparent response, Ahmadinejad said that "reports released by al-Qaida are usually believed to be produced by the CIA".