Accepted wisdom about Al-Qaeda is that the terrorist network has been so greatly weakened since 2001 that it no longer, as an organization, poses the world's biggest terrorism threat.
Still, eight years after the September 11 terrorist attacks in the United States, the fate of Al-Qaeda leader Osama bin Laden remains unknown. Experts continue to warn of terrorist cells or loosely affiliated groups that have been inspired by Al-Qaeda's ideology of global jihad.
"Al-Qaeda as we envision it in terms of the September 11th attack is not the Al-Qaeda of today," Maha Azzam, an associate fellow in the Middle East and North Africa program at Chatham House, a London-based think tank, tells RFE/RL. "There are cells that are willing to carry out possibly atrocious acts of terrorism, but they are not necessarily working under the same leadership or the same organizational structure."
"We still face a threat," Azzam says. "The threat remains that it only takes a small cell or a number of individuals to carry out a terrible act of terrorism that can emerge from any part of the world."
Hijacked United Airlines Flight 175 hurtles toward the World Trade Center on September 11, 2001.
British Prime Minister Gordon Brown said in December that three-quarters of the most serious terrorist plots investigated by British authorities have links to Al-Qaeda leaders in Pakistan. But Pakistani diplomats refute that claim -- saying Britain needs to take responsibility for issues that drive young British Muslims toward extremism.
Still, evidence suggests Al-Qaeda was trying to orchestrate terrorist attacks of global proportion from Pakistani territory as recently as 2006 by passing instructions through a courier willing to travel to and from Pakistan to disseminate plans.
A case in point is the conviction this week of three members of a British Al-Qaeda cell of a 2006 plot to attack at least seven trans-Atlantic airliners. British and U.S. intelligence officials say the investigation revealed direct links between militant British Muslims and senior Al-Qaeda leaders in Pakistan.
Al-Qaeda struck again in London on July 7, 2005, killing 52 people and wounding more than 700 others.
Counterterrorism officials in the U.K. suspect the mastermind of the 2006 attack plan was Egyptian-born Abu Obaidah al-Masri -- a senior Al-Qaeda planner based in Pakistan at the time. Al-Masri also has been cited as the inspiration for the deadly July 7, 2005 suicide bombings in London. He reportedly died of hepatitis in Pakistan in April 2008.
The key link between the British Al-Qaeda cell and Al-Qaeda leaders in Pakistan is said to have been a fixer named Rashid Rauf. The son of a British baker, Rauf was arrested in the central Pakistani city of Bahawalpur in August 2006.
Pakistani officials say Rauf escaped from their custody in December 2007. In November 2008, he reportedly was targeted in a U.S. drone strike near Pakistan's border with Afghanistan. But intelligence officials in the U.S. and Britain remain uncertain whether he was killed.Technological Terrorism
Meanwhile, research suggests that Al-Qaeda has become increasingly skilled in recent years at using the Internet to communicate directives within the jihadist network -- often using insider references and coded language derived from Islamic theology and history.
Some critics say counterterrorism efforts should focus more on those Islamist texts on the Internet to better determine which have come from authoritative Al-Qaeda figures -- and thus predict major Al-Qaeda attacks before plans are carried out by local cells.
Nigel Inkster, director of Transnational Threats and Political Risk at the International Institute for Strategic Studies in London, says he thinks Al-Qaeda's senior leadership is still situated along the Afghanistan-Pakistan border, mostly in Pakistan's tribal areas.
But Inkster says increased activity by Pakistani forces in those areas, together with shared U.S. intelligence and drone strikes, have made it much more difficult for Al-Qaeda to direct global operations from Pakistan.
"It is probably more sensible now to look at Al-Qaeda less as a terrorist organization as such, but rather, as a movement," Inkster tells RFE/RL. "[It is] an organization that acts as a kind of ideological umbrella for lots of different groups which are actually disaggregated and decentralized."Branching Out
Azzam sees two parallel developments in Al-Qaeda's recent evolution. On the one hand, she says Al-Qaeda has become disconnected, operationally decentralized, and weakened.
Have the actions of Pakistani troops, like this one in Khyber near the Afghan border, "greatly weakened Al-Qaeda activities"?
"The role of the Pakistan Army has greatly weakened Al-Qaeda activities," she says. "I can't see a serious reversal of that. If Osama bin Laden or some of his supporters are still in the Pakistan-Afghanistan area, there is very little likelihood of them reinvigorating the organization in a way where it can be any serious threat from those bases."
Meanwhile, Azzam says smaller groups are trying to claim the leadership of Al-Qaeda and centralize their activities -- from a group in North Africa that calls itself "Al Qaeda in Islamic Maghreb" to a merger early this year of Al-Qaeda's Saudi and Yemeni branches that calls itself "Al-Qaeda in the Arabian Peninsula."
Like most experts, Inkster says he thinks Osama bin Laden probably is still alive and continues to spread Al-Qaeda's ideology through video and audio messages:
"I think Osama bin Laden has been on video coverage recently enough for it to be a reasonable assumption that he is still alive," Inkster says. "And I suspect that he probably is still in the border region in [Pakistan's] tribal areas, living in circumstances where I suspect that he has very little day-to-day visibility or control over Al-Qaeda's operational activity.
"For him, at the moment, I think survival is probably the key," Inkster concludes of bin Laden. "I have no reason to believe that he is dead and a certain amount of evidence to suggest that he is probably alive."'Very Much Around'
But Rahul Bedi, a South Asia correspondent for "Jane's Defence Weekly," says he is less certain about bin Laden's fate.
Bedi says recent technology makes it easier for Osama bin Laden videos to be faked. He also says that if Osama bin Laden had been killed, it would be in Al-Qaeda's interest to perpetuate the myth that he was still alive.
With or without bin Laden, Bedi says it is a mistake to underestimate Al-Qaeda's ability to continue orchestrating global terrorist attacks from Pakistani territory.
Rebuilding at Ground Zero, the former site of the World Trade Center, in New York on August 3, 2009
"Al-Qaeda is very much around," Bedi tells RFE/RL. "Its capacity to carry out attacks like it did on September the 11th may have depreciated for the moment; but I think it is becoming stronger and regrouping, and it could pose a bigger threat in the months and years to come. It has expanded by including the Afghan Taliban as well as the Pakistan Taliban, as well as a lot of other Pakistani militant groups."
Bedi concludes that some Al-Qaeda figures may have fled Pakistan for ungoverned or weakly administered areas like Somalia, Sudan, Algeria, or Yemen. But he says the terrorist network continues to derive both financial and tactical strength from Pakistan's tribal areas and from parts of Afghanistan near the border with Pakistan.