Pakistani and Taliban officials interviewed by Newsweek say the Qaeda No. 2, Ayman Al-Zawahiri is behind the wave of retaliatory attacks launched after Pakistani troops overran the Red Mosque in Islamabad, which have killed more than 150 people. While Osama bin Laden has been keeping a low profile, Zawahiri has moved aggressively to take operational control of the group. In so doing, Zawahiri has provoked a potentially serious ideological split within Al Qaeda over whether he is growing too powerful and has become obsessed with toppling Pakistani President Pervez Musharraf, according to two jihadists interviewed by Newsweek last week.

Bin Laden himself has not personally intervened to end the internal feud, according to the jihadist sources. For security reasons he rarely has face-to- face meetings with his deputies. "He doesn't want to get involved," says Khan. "He's already too busy with strategic planning and inspirational duties and with directing his own security." Instead, bin Laden has tried to resolve the dispute by dividing duties between the two factions and appointing a pair of mediators, these sources tell Newsweek.

"Libyans tell me that the sheik [bin Laden] has not appointed a successor and that only the U.S. government and the international media talk of Zawahiri as being the deputy."

A senior U.S. official involved in counterterrorism policy, speaking on condition of anonymity because he was addressing sensitive matters, agrees that there are tensions between Al Qaeda's Egyptian and Libyan factions, as well as between Saudi and Central Asian elements. "These guys are not immune to nationalist tendencies," he says. John Arquilla, an intelligence expert at the Naval Postgraduate School who closely follows radical Islamist traffic, calls it "the battle for Al Qaeda's strategic soul. There is a profound strategic debate over whether to focus on overturning the government in Pakistan ... because that puts them in control of a nuclear capacity."

But they fear that Zawahiri is inviting the Pakistani leader's wrath, prematurely opening up another battlefront before the jihadists have properly consolidated their position.