The killing of Osama bin Laden will deal a big psychological blow to al-Qaida but may have little practical impact on an increasingly decentralised group that has operated tactically without him for years.
Nearly a decade after the Sept. 11, 2001, attacks, al-Qaida has fragmented into a globally-scattered network of autonomous groups in which bin Laden served as an inspirational figure from the core group's traditional Pakistan-Afghanistan base.
Counter-terrorism specialists describe a constantly mutating movement that is harder to hunt than in its turn of the century heyday because it is increasingly diffuse -- a multi-ethnic, regionally dispersed and online-influenced hybrid of activists.
While this network remains a threat, the core al-Qaida leadership has been weakened by years of U.S. drone strikes in Pakistan. It has not staged a successful attack in the West since London bombings that killed 52 people in 2005.
Al-Qaida has also been hurt ideologically by uprisings in the Arab world by ordinary people seeking democracy and human rights — notions anathema to bin Laden, who once said democracy was akin to idolatry as it placed man's desires above God's.
The arm of al Qaeda that now poses the biggest threat to the United States is its affiliate in Yemen, al Qaida in the Arabian Peninsula (AQAP), according to U.S. officials. Other al Qaida-linked groups have grown in ambition and lethality.
"As a matter of leadership of terrorist operations, bin Laden has really not been the main story for some time," said Paul Pillar, a former senior U.S. intelligence official.
"The instigation of most operations has been at the periphery not the center — and by periphery I'm including groups like AQAP but also smaller entities as well."
It was AQAP that claimed responsibility for a thwarted Christmas Day attack aboard a U.S. airliner in 2009 and an attempt last year to blow up two U.S.-bound cargo planes with toner cartridges packed with explosives.
The head of the U.S. National Counterterrorism Center, Michael Leiter, acknowledged to Congress this year that AQAP and its chief English-language preacher Anwar al-Awlaki posed the biggest risk to the United States.
Al-Awlaki, a U.S. citizen who left the country in 2001 and joined al-Qaida in Yemen, also communicated with a U.S. Army major who in November 2009 allegedly went on a shooting rampage at Fort Hood, Texas that killed 13 and wounded 32.
The Pakistani Taliban claimed responsibility for a failed bombing in New York City's Times Square a year ago.
"I don't think there's any real military significance" to bin Laden's death, said Arturo Munoz, a security analyst at RAND Corporation.
"The significance is political and psychological and psychologically and politically, there's a huge significance."
"Bin Laden's death is a significant victory for the United States. But it is more symbolic than concrete," said Fawaz Gerges, an al Qaida expert at the London School of Economics.
"The world had already moved beyond bin Laden and al Qaida. Operationally al Qaida's command and control had been crippled and their top leaders had either been arrested or killed.
"More importantly, al Qaida has lost the struggle for hearts and minds in the Arab world and elsewhere and has had trouble attracting followers and skilled recruits."
Bin Laden's ability to evade U.S. capture for nearly a decade was a huge embarrassment to the United States, a painful reminder now extinguished by his killing in a firefight in a compound north of Islamabad.
Some analysts say that bin Laden's memory may now inspire followers, who will now see him as a martyr, to take revenge.
And the extensive online forums, chat rooms and websites operated by al Qaidasympathizers will ensure his role as the group's motivator-in-chief will endure.
"As a symbol, as a source of ideology, bin Laden can continue to play those roles dead as well as alive," Pillar said.
But his departure will add to pressure on morale throughout the network, despite al Qaida's glorification of martyrdom and a perception that bin Laden died an honourable death in battle.
Gerges said it would "take a miracle" for al Qaida to recover ideologically and operationally from bin Laden's death.
Thomas Hegghammer, a specialist on militancy at the Norwegian Defence Research Establishment, said that over the long term his loss would deepen the group's disarray.
"It is bad for al Qaida and the jihadi movements. Bin Laden was a symbol of al Qaida's longevity and its defiance of the West. Now that symbol is gone."
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