Editor's note: Paul Cruickshank is an analyst on terrorism for CNN and Alumni Fellow at the NYU Center on Law and Security
New York (CNN) -- The killing of Osama bin Laden is "an enormously significant moment in the fight against al Qaeda terrorism," and there is no one poised to take his place as the group's leader, says CNN terrorism analyst Paul Cruickshank.
President Obama announced Sunday night that U.S. forces killed bin Laden in a mansion outside the Pakistani capital of Islamabad. The strike came as the nation approaches the 10th anniversary of the al Qaeda attacks on September 11, 2001, that killed almost 3,000 people in the United States.
"Even after 9/11, bin Laden continued to be the strategic guiding force for al Qaeda, signing off on the biggest operations, according to western officials," Cruickshank, an Alumni Fellow at the New York University Center on Law and Security, said in an interview.
"He was the linchpin of al Qaeda. Without him, al Qaeda could fracture. There are lots of centrifugal forces within al Qaeda, people with different ideologies and agendas. Bin Laden was able to unify them. He's irreplaceable. There's no one with his level of charisma, fame or visibility."
CNN: Who else could step forward?
Cruickshank: [Ayman al] Zawahiri doesn't have anything like his charisma; he has always been a much more polarizing force than bin Laden. Abu Yahya Al Libi, a key Libyan idealogue for al Qaeda, has some charisma, but none of his stature. Ilyas Kashmiri, a Pakistani veteran militant, has emerged as a key mastermind of international terrorism operations but again has nothing like bin Laden's stature. Nor has Anwar al Awlaki.
CNN: How did bin Laden emerge?
Cruickshank: Bin Laden earned his name fighting against the Soviets in the mid- to late-1980s in Afghanistan, He was famous at that time throughout quite a lot of the Arab world, particularly in jihadist circles, for his "bravery," or at least how it was presented in the pages of Jihad magazine, the magazine of the Jihad against the Soviet Union.
By the end of the 1980s when he founded al Qaeda, he was already somebody with significant stature with the jihadist movement. He then used that stature eventually to reorient this new organization against the United States.
CNN: What form did that take?
Cruickshank: Al Qaeda wasn't founded to attack the United States to start off with, but by the early 1990s bin Laden, who had long espoused anti-American views, decided it needed to attack United States interests. The arrival of U.S. troops in Somalia in the early 1990s was the trigger for bin Laden's decision to focus on the United States. Bin Laden declared war against the U.S. in 1996 and against American civilians in 1998, a chain of events that led to the U.S. embassy bombings in Nairobi and Dar es Salaam, the attack on the U.S.S. Cole, 9/11, and the July 7, 2005, London bombings.
Bin Laden really did run al Qaeda with a tight grip. The ultimate decision was always his.
CNN: Were you surprised that bin Laden wasn't in a remote part of Pakistan?
Cruickshank: Al Qaeda is clearly based in the tribal areas of Pakistan, and that's where they're providing operatives with the crucial bomb making training to launch attacks in the West, many times using western operatives they've recruited to launch those attacks.
Many analysts thought bin Laden may have been in the tribal areas, North Waziristan for instance, which has been a safe haven for al Qaeda since 2004. But because of intensified U.S. drone strikes in the area in recent years, bin Laden may have concluded it wasn't safe for him to be there. By hiding in a Pakistani city, bin Laden would not have been exposed to such strikes. It is possible, as well, that bin Laden has been hiding in an urban area in Pakistan for many years.
CNN: What's left of al Qaeda today?
Cruickshank: There are probably several hundred members of al Qaeda in the Pakistan/Afghanistan border region, most of those being on the Pakistani side of the border, most of them in the tribal areas of Pakistan
They've got a hundred or so operatives in Yemen, with al Qaeda in the Arabian Peninsula, the affiliate operation, and hundreds of other operatives in other affiliates around the world. What we've seen in recent years is the rise in the threat to the West from the affiliates, particularly al Qaeda in the Arabian Peninsula, which has become the most operationally active organization when it comes to plots against the United States.
When it comes to the most dangerous safe haven, that's still regarded as Pakistan, and al Qaeda Central is still the organization that is most likely to organize spectacular mass casualty attacks. Obviously removing their leader is a huge, huge breakthrough.
CNN: Why is the death of bin Laden such a breakthrough?
Cruickshank: Al Qaeda was much bigger than bin Laden to one degree because there was a small but significant radical fringe -- perhaps in the thousands around the world -- that bought into its ideology. But at the same time bin Laden was over the years key to inspiring extremists to take the key step of volunteering for al Qaeda operations. Bin Laden was also key to spreading al Qaeda's central message -- that the U.S. and its allies were engaged in a war against Islam and needed to be violently confronted. Bin Laden in recent years continued to get that message across each time he released a video or audiotape.
That did help the organization continue to be relevant, and bin Laden continue to be relevant, even though he wasn't able to be so operationally involved like he had been before.
CNN: What will happen to al Qaeda now?
Cruickshank: I think that in the short term, there could be a spike in activity, with more people being recruited, because he's going to be a martyr figure in the short term. But in the medium term, they're really going to feel the loss. He was very good at coming up with messages that would unify al Qaeda, for instance in the 1990s focusing on the United States, that was a way to unify all these different factions, different nationalities and agendas -- and picking on issues such as the cartoon controversy to unify al Qaeda. Now without bin Laden, they will likely lose some of that unity.
Coming after a backlash against al Qaeda in the Muslim world -- the emergence of a powerful critique of al Qaeda from fellow Jihadists for killing so many Muslims and civilians -- and the Arab spring that has reduced al Qaeda to virtual irrelevance in much of the Arab world and removed grievances they were able to exploit, this is a hammer blow to al Qaeda.
The threat of al Qaeda won't go away anytime soon, as the thwarting of a serious al Qaeda plot against Germany last week demonstrated. Bin Laden's ideology has been spread too wide for that. But without the guiding hand of its founder, the al Qaeda organization may now begin to unravel.