For much of the world, Osama bin Laden was the face of al Qaeda. He was, after all, the man who oversaw the September 11, 2001, attacks.

With bin Laden gone, the question now becomes "What happens to al Qaeda?"

Within hours of bin Laden's death, questions began to emerge about who would take the helm of the organization and whether it would create an opportunity for other Islamic organizations to step up.

"Al Qaeda is weakened. But it doesn't mean that the United States has no challenges," Steven L. Spiegel, director for Middle East development at the University of California Los Angeles, said Monday.

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Standing behind bin Laden for more than two decades has been an ideological army that stretches around the world, where militants have set up their own "al Qaeda franchises," analysts said.

"He was very good at coming up with messages that would unify al Qaeda," said Paul Cruickshank, a CNN analyst for terrorism and an alumni fellow at the New York University's Center on Law and Security.

"Now without bin Laden, they will likely lose some of that unity."

 

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That loss could make room for groups such as the Muslim Brotherhood, the largest political opposition party in many Arab states, and Hamas, considered a terrorist organization by the United States, to gain traction, Spiegel said.

Many expect al Qaeda to strike back following bin Laden's death. The U.S. State Department has issued a worldwide travel advisory for American citizens traveling abroad.

"I think that there will be reprisals, not necessarily from al Qaeda itself, although they'll try, but also in Pakistan," said Peter Bergen, CNN's national security analyst.

"I think that we'll see protests in the streets of Pakistan and some violence ... against American and also Western targets."

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Bergen, who met bin Laden in 1997, said he believes al Qaeda will be irrecoverably damaged by the death o">Inside the place bin Laden was killed