The death of the American-born radical Muslim cleric Anwar al-Awlaki is a "major blow" to al-Qaida, according to president Barack Obama.
But while the president welcomed the death of the "YouTube Bin Laden", the US authorities were in no hurry to overtly claim credit for the assassination as they managed the potential fallout of the killing in Yemen and across the Middle East.
Speaking a few hours after the drone strike that killed Awlaki, Obama made only a few brief remarks on the subject, describing his death as "another significant milestone" in America's fight against al-Qaida. The US regarded Awlaki as one of al-Qaida's most dangerous operatives because of his potential appeal to western radicals. "This is further proof that al-Qaida and its affiliates will have no safe haven anywhere in the world," Obama said.
But Obama's low key speech stood in marked contrast to the assassination of Osama bin Laden, which was rapidly followed by media briefings and photographs of the president and his team observing the operation.
"I can't talk about the operational details," Obama said in a radio interview on Friday when asked if he had ordered the killing. "This is something that we have been working with the Yemeni government for quite some time."
In large part the reticence reflects US sensitivities about Yemen, a country in violent turmoil and where US involvement has provided a propaganda coup for Muslim radicals. Secret US diplomatic cables released last year by WikiLeaks and the Guardian reveal the secrecy that surrounded an offer by Yemen's president to Washington of "unfettered access" to carry out unilateral strikes against top al-Qaida targets on his soil.
The cable narrates how president Ali Abdullah Saleh effectively "outsourced" Yemen's own counter-terrorism efforts to the United States.
In line with the covert US approach revealed in the cables, details of the Awlaki operation remain scant. The Yemeni government announced that Awlaki was "targeted and killed" around 9.55am outside the town of Khasaf in a desert stretch of Jawf province, 87 miles (140km) east of the capital Sana'a.
Saba, Yemen's official news agency, reported that the attack also killed Samir Khan, an American citizen who was an editor of Inspire, an al-Qaida-affiliated English-language internet magazine. Last year Khan wrote a piece for Inspire titled: "I am proud to be a traitor to America." Several bodyguards are also believed to have been killed, but no details have been given.
A senior tribal chief who helped bury the bodies in a cemetery in Jawf told the Associated Press that seven people were killed in the strike, their bodies completely charred. The chief said the brother of one of the dead, who had given the group shelter in his home, had witnessed the strike.
According to the chief, the witness said Awlaki was travelling in a pick-up with six other people on their way to neighbouring Marib province. They stopped for breakfast in the desert and were sitting on the ground to eat when they spotted drones, so they rushed to their truck. A Hellfire missile fired from a drone struck the truck, leaving it a charred husk and killing all of those inside. The chief spoke on condition of anonymity because he did not want to be connected to the group, and he did not identify the witness.
US officials were unwilling to go into detail about America's role in Awlaki's killing. But it is likely that the hunt for Awlaki would have been overseen by the CIA, in large part to enable it to be classified as "covert action" that not only gives the American pursuers a freer hand in how they operate, but means they are not obliged to seek the approval of the Yemeni government.
The CIA launched a failed drone attack to kill Awlaki in May after Obama gave the unusual authorisation for the killing of an American citizen. It was revealed in June that the CIA is building a secret base in an unnamed Middle Eastern country to launch drone attacks within Yemen – without the necessity of informing President Ali Abdullah Saleh's US-friendly but beleaguered administration, which has an uncertain future.
But the CIA has not been alone. Much of the pursuit of al-Qaida targets in Yemen has been carried out by the "hunter-killer teams" from the highly secretive Joint Special Operations Command (JSOC), a military operation that has its own drones and can call on air strikes. It was members of the Navy's special operations forces under the command of JSOC who killed Osama bin Laden in Pakistan in May.
According to a recent book, Top Secret America, by Washington Post reporters Dana Priest and William Arkin, JSOC has launched intelligence operations and lethal raids, not only in countries where the US is fighting openly – Iraq and Afghanistan – but in Pakistan, Somalia, the Philippines, Nigeria and Syria. And in Yemen.
However, JSOC is not legally permitted to carry out covert operations – in which the US role is not acknowledged – of the kind pursued by the CIA. Technically JSOC's operations are defined as "traditional military activities" requiring disclosure.
But Priest and Arkin write that is a fine distinction in practice. "Many national security officials, however, say JSOC's operations are so similar to the CIA's that they amount to covert action. The unit takes its orders directly from the president or the secretary of defence and is managed and overseen by a military-only chain of command," they write.
The administration's unwillingness to detail US involvement also reflects the fact that this was a much more controversial operation than the assassination of Bin Laden.
Awlaki was a US citizen, had not been indicted for any crime, and the strike took place in a country where US forces are not officially waging war.
Whatever the legalities, Awlaki's death has sparked a debate over how significant his demise will prove to be. Professor Rohan Gunaratna, head of the the International Centre for Political Violence and Terrorism Research in Singapore, said Awlaki's killing was a significant blow to al-Qaida.
"Anwar al-Awlaki was not only the a ideological leader, he was an operational leader. He was a Bin Laden in the making but he would have posed an even greater threat because he understood the western world, especially the Musilims living in the west," he said.
"Awlaki was the go-to cleric for English-speaking Muslims who sought to engage in violent jihad. He was the most influential radical tourism recruiter for Islamic revolutionary groups, and he was savvy about using new media, and old," said Charles Kurzman, author of The Missing Martyrs: Why There are so Few Muslim Terrorists.
But Kurzman said Awlaki's influence had ultimately proved minimal. "He saw revolutionary violence as an individual duty that was required of every Muslim. Fortunately virtually all Muslims disagreed."
Kurzman said: "Given that Awlaki's messages is sitting on the internet, easily accessible to millions of English-speaking Muslims, it's very interesting how few have taken him up on his demand that Muslims join the revolutionary movement."
Security officials on both sides of the Atlantic believe that Awlaki's death is further evidence that the strategy of targeting al-Qaida's leaders is working.
Crucially, say American officials, it is not just the top tier that has been removed.
"The attrition reaches right into the organisation,' said one US diplomatic source. "You are now talking about the of people who the public have never heard of. The strength in depth that was so important a few years ago simply isn't there any longer. Once it was the 'number three' who was always taken out because he was exposed. "Now it's numbers four to forty who are being hit, too."
There is also quiet satisfaction elsewhere. In Saudi Arabia, senior interior ministry officials say that al-Qaida, once a major security problem in the country, is now "dying if not dead".
Many of the top Saudi militants left their native land to take refuge in the Yemen which appears now to be less of a safe haven than they may have thought.
