Ayman al Zawahiri's succession to the leadership of al Qaida, announced over the Internet Thursday, carries particular dangers for Pakistan, a nuclear-armed country reeling from an Islamic insurgency, a faltering economy, endemic corruption and poor governance.
Like al Qaida's late founder Osama bin Laden, Zawahiri is believed to be hiding in Pakistan since fleeing the 2001 US invasion of Afghanistan. Unlike bin Laden, though, Zawahiri has been closely involved with Pakistani extremist groups, married into a local tribe and has aggressively advocated a jihadist takeover.
"This is very bad news for Pakistan," said Muhammed Amir Rana, the director of the Pakistan Institute for Peace Studies, an independent research organization in Islamabad. "Zawahiri has ambitions to capture a territory or a state. He believes that Pakistan is fertile ground to become the biggest stronghold of al Qaida."
US officials largely dismissed the development. They insisted that al Qaida has been seriously hurt by bin Laden's killing in a May 2 raid by US Navy SEALs near the Pakistani capital, and by drone strikes close to the border with Afghanistan that have killed a large number of key network members.
"I'm not sure it's a position that anyone should aspire to," Defense Secretary Robert Gates said of Zawahiri's elevation by al Qaida's leadership council. "I think he will face some challenges."
Gates, however, added that despite its "huge losses," the terrorist network remains a threat.
State Department spokeswoman Victoria Nuland noted that the popular revolutions sweeping the Middle East have mostly embraced peaceful democratic change, rejecting al Qaida's calls for the establishment of hard-line Islamic rule through the violent overthrow of the region's autocrats.
"Frankly, it barely matters who runs al Qaida because al Qaida is a bankrupt ideology," Nuland said.
Zawahiri, a 59-year-old Egyptian, was named as the new al Qaida "emir" on an Islamist website. While his succession wasn't a surprise, the length of time it took to announce led some to suggest that factions in al Qaida opposed him.
"We seek with the aid of God to call for the religion of truth and incite our nation to fight...by carrying out jihad against the apostate invaders...with their head being crusader America and its servant Israel, and whoever supports them," the statement said.
The statement also sought to embrace the Middle East revolutions — as had a video recording released by Zawahiri earlier this month — calling on people to rise up against "all the corrupt, unjust regimes the West has enforced on our countries."
His elevation comes at a brittle time for insurgency plagued Pakistan. Washington is pushing the Pakistani military to launch joint operations to eliminate what remains of al Qaida's core leadership, on the run as never before following bin Laden's death.
But cooperation between Islamabad and Washington is at an all-time low, fueled by popular outrage at the US for staging the raid that killed bin Laden without informing Pakistan's powerful military. The military also has suffered humiliating criticism for failing to detect the helicopter-borne operation.
Some experts question whether Zawahiri can command the same loyalty as bin Laden, saying that his Egyptian nationality, academic style and advocacy of extreme violence could alienate some network members and make it harder for him to raise money and recruit operatives.
"Zawahiri has not demonstrated strong leadership skills in the past. He is much less charismatic than bin Laden," said a US counterterrorism official who requested anonymity because of the sensitivity of the issue.
But Bruce Hoffman, a terrorism expert at Georgetown University, said that Zawahiri essentially has been a "co-emir" with bin Laden since merging his Egyptian Islamic Jihad with al Qaida in 2001.
"Zawahiri probably has as solid a pedigree as bin Laden did," Hoffman said, noting that he's been an extremist since his teens, was jailed in the 1981 assassination of Egyptian President Anwar Sadat and developed al Qaida's targeting strategy.
His strategic thinking is partly behind al Qaida's ability to transform itself from a group into an ideology, with offshoots in the Middle East, North Africa and elsewhere.
While bin Laden's trail went cold following his escape from Afghanistan in 2001, there were reported sightings of Zawahiri. US intelligence believes it came close to killing him several times in Pakistan's tribal area.
Zawahiri has met frequently with Pakistani militant groups and mentored them, said Rana, the researcher.
In the video earlier this month, Zawahiri said, "I incite the crowds of the Muslim Ummah (community) in Pakistan to revolt against the mercenary soldiers and the bribed politicians who are in control of their (Pakistan's) fate," and called Pakistan an American colony.
As long ago as 2003, Zawahiri had urged Pakistanis to oust the then military dictator, Pervez Musharraf. Months later, Musharraf narrowly escaped two assassination attempts.
Zawahiri also instigated a bloody revolt in 2007, following a clash between the government and extremists at Islamabad's Red Mosque, telling Pakistanis in a video recording to "die honorably in the fields of jihad, and don't live like women."
The confrontation, which killed around 100 hard-liners holed up inside the mosque, kicked off the insurgency by Pakistani jihadists. The rebellion has since killed tens of thousands, rocking the only Muslim-majority country with a nuclear arsenal.
Zawahiri has targeted the Pakistani military, the institution often credited with holding the country together, saying in a 2006 message, that it "has turned into hunting dogs for the sake of the Crusaders." Al Qaida sympathizers within the armed forces are widely considered a serious threat to the country's stability.
Zawahiri has repeatedly warned that the US wants to seize the country's nuclear weapons, playing into a paranoia that already grips Pakistan, especially its armed forces.
In a tract on Pakistan released in late 2009, called The Morning and the Lamp, Zawahiri called for the destruction of the Pakistani state, explaining in detailed theological argument why it was un-Islamic.
However, in an apparent recognition that al Qaida's bloodthirsty methods have alienated most of the Muslim world, Zawahiri stepped back in this month's video from his usual call for unremitting violence. He suggested that al Qaida showed more compassion against its enemies than the US did, saying, "This is the difference between the earth and the sky."
Noman Benotman, a former close associate of Zawahiri, who now works as an analyst at Quilliam, an "anti-extremist" research organization in London, said: "Zawahiri's first step as leader will be to try to decontaminate the group's reputation in the Muslim world. Ever since the Iraq war, al Qaida has been mistrusted by many Muslims and even by other hard-line Islamist groups for its killing of Muslim civilians."
Shah, a McClatchy special correspondent, reported from Islamabad. Landay reported from Washington.