WASHINGTON / BEIJING - The killing of Osama bin Laden will deal a big psychological blow to al-Qaida but may have little practical impact on an increasingly decentralized 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.

Related readings:  Bin Laden dies, but the terror threat lives on  Bin Laden's wife not killed in raid: White House  US official: New tape may be last from bin Laden  US says bin Laden's death does not end Afghan war  Not everyone believes bin Laden really is dead

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 US drone strikes in Pakistan. It has not staged a successful attack in the West since London bombings that killed 52 people in 2005.

The arm of al-Qaida that now poses the biggest threat to the United States is its affiliate in Yemen, al-Qaida in the Arabian Peninsula (AQAP), according to US 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 US 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 US airliner in 2009 and an attempt last year to blow up two US-bound cargo planes with toner cartridges packed with explosives.

The head of the US National Counterterrorism Center, Michael Leiter, acknowledged to Congress earlier this year that AQAP and its chief English-language preacher Anwar al-Awlaki posed the biggest risk to the United States.

Al-Awlaki, a US citizen who left the country in 2001 and joined al-Qaida in Yemen, also communicated with a US 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.

Dong Manyuan, an anti-terror expert at the China Institute of International Studies, told China Daily the death of bin Laden is unlikely to stop terror attacks, but instead may bring a new round of reprisals against the US and pro-US forces.

Bin Laden's death can be used by the Taliban as an excuse to launch new attacks in the name of inheriting his cause, said Dong.

Under such circumstances, the US, on high alert, will intensify terror prevention on its own territory, but other nations, including Afghanistan and Pakistan, will be in great danger, said Dong.

"If entering the US becomes difficult, al-Qaida is likely to target Pakistan and Afghanistan, and attack their military and civilians," said Dong.

The US has promised to begin to withdraw its troops from Afghanistan no later than July this year, "but it makes it impossible for the US to withdraw as Afghanistan will face mounting pressure since al-Qaida may turn its spearhead toward it," said Dong.

Ye Hailin, a professor of international studies at the Chinese Academy of Social Sciences, said that the death of bin Laden, though a historic moment for the US, will not necessarily affect US' anti-terror policies, including its plan in Afghanistan.

China Daily-Reuters