Until recently, Al-Qaeda leader Osama bin Laden's top deputy, Egyptian Ayman al-Zawahri, was thought to be surrounded there. But Pakistani and Afghan officials now say the man in question may be the Uzbek Tahir Yuldashev, another top bin Laden ally in Afghanistan.
Mark Burgess is a research analyst specializing in military and terrorism issues at the Center for Defense Information, a private policy research center in Washington. Perhaps Al-Qaeda's leaders can no longer operate freely in Afghanistan, Burgess tells RFE/RL, but they are still able to pursue their goals.
"What success we have seen in the war on terrorism has dispersed [Al-Qaeda leaders]. The leadership has had to devolve and evolve at the same time. So what you're getting probably is, within Al-Qaeda itself, a lot more decisions by men on the spot rather than any sort of centralized leadership. It's a leaderless organization in that sense -- leaderless leadership, if you will," Burgess said.
Al-Qaeda was reportedly founded by Osama bin Laden during the effort to drive Soviet forces from Afghanistan. After that, its goals broadened to include opposition to secular governments in predominantly Muslim nations and the presence of U.S. and other foreign troops in those countries, particularly Saudi Arabia.
Once the Taliban came to power in Afghanistan, Al-Qaeda set up training camps there for its own fighters and those of other Muslim militant groups. It is now believed to have affiliate cells in more than 50 countries.
It was most likely in Afghanistan where bin Laden and al-Zawahri plotted several attacks against American interests in the Middle East and, eventually, the assaults of 11 September 2001.
But bin Laden and his senior associates never stayed in one place very long, even in Afghanistan. The United States tried to kill bin Laden in a missile strike in Afghanistan in 1998 in retaliation for the bombings of the American embassies in Kenya and Tanzania. But bin Laden and his followers already had decamped.
After blaming Al-Qaeda for the 11 September attacks, the United States went to war in Afghanistan, targeting not only Al-Qaeda but also the Taliban for harboring the terror network. U.S.-led forces and their Afghan allies quickly routed the Taliban and scattered Al-Qaeda. But that has not stopped the organization and its affiliates from mounting attacks.
Danielle Pletka is the vice president for foreign and defense studies at the American Enterprise Institute, another private Washington think tank. She tells RFE/RL that Al-Qaeda is so flexible because it does not have a traditional hierarchical structure.
"Rather than a vertically integrated organization, [Al-Qaeda] is a horizontally integrated organization. That means that you have different cells all over the place that are connected by this common ideological thread, occasionally connected by training. They may be connected by a common leader and a common aim, but at the end of the day, they're perfectly capable of operating separately. And so, if you take away the head, the horizontal integration still works," Pletka said.
Further, both Pletka and Burgess say militant Islamic groups other than Al-Qaeda may have been responsible for at least some of the terrorist attacks of the past 2 and 1/2 years -- from the bombing on the Indonesian island of Bali in October 2002 to the rail bombings in Madrid this month.
Pletka says that because of its successes and its global reach, Al-Qaeda has been able to attract affiliate groups. She says these affiliates seem to have become as central to Al-Qaeda as its original cells because of the network's loose structure. Pletka says they can share in its training and perhaps occasionally get financial support, but they do not necessarily take orders from a central command.
Burgess adds that some of the more recent attacks may not have been known to Al-Qaeda before they happened. Rather, he says, they may have been inspired by Al-Qaeda but carried out by groups that have no formal affiliation.
"[Al-Qaeda is] as much an inspiration as anything else. Al-Qaeda don't actually have to carry out any operations themselves. They don't need to sanction operations themselves. They just need to provide a degree of inspiration. And if other Islamic terrorists are responsible [for a given attack], then, by default, we then blame Al-Qaeda. And it's like Al-Qaeda has carried out an operation, which in all likelihood Al-Qaeda has not carried out," Burgess said.
As a result, both Burgess and Pletka say the capture of al-Zawahri or even bin Laden himself almost certainly would not mean an end to the war of Muslim militants against the West. Burgess says the principal benefit would be a boost to the morale of those working to counter terrorism in Europe and the United States.
Pletka agrees that Al-Qaeda's attacks would continue, but she adds that the capture of bin Laden or al-Zawahri -- particularly al-Zawahri -- could still have some effect on operations.
"Al-Zawahri has been called an ideological and, I think, operational key to Al-Qaeda, and so I don't think that we should say glibly, 'This will make no difference, it's only a moral victory,'" Pletka said.