WASHINGTON – Osama bin Laden emerged Friday as possibly a key figure in a European terror plot, raising speculation he may be flexing his muscles in a move to show a besieged al-Qaida remains strong and able to launch major attacks on Western targets.

U.S. counterterrorism officials said they believe that senior al-Qaida leaders, including bin Laden, were involved in the plan to strike several European cities in a coordinated assault. If bin Laden had a direct hand in the planning, it would be the most active role he has played in a terror plot since the 9/11 attacks, according to U.S. officials and analysts.

Counterterrorism officials said that they are now working under the assumption that bin Laden played a role in the plotting, but they would not detail what indications they’ve seen that led them in that direction.

Still, some also believe that bin Laden’s orders may have been delivered by one of his top commanders, because the al-Qaida leader is known to avoid close contact with anyone except his closest confidants.

While bin Laden’s name is still a powerful reminder of the World Trade Center’s twin towers and the Pentagon engulfed in flames, U.S. officials have for months asserted both in private and in hearings on Capitol Hill that his core al-Qaida group is weakened, struggling to raise money and attract recruits.

“There is a great deal of pressure on al-Qaida to do something to show that it is still alive and kicking,” said Richard Barrett, the head of a U.N. group that monitors the threat posed by al-Qaida and the Taliban. “They need to show they’re strong, they’re a force multiplier, that they’ve still got some beef, that they’ve got operators abroad, that they can do things.”

Barrett said al-Qaida’s Pakistan-based network has not launched a successful attack since the London subway bombing in 2005. “In order to attract the younger new recruits, I think they have to do a bit better than that,” he said.

The multi-pronged scope of the emerging terror plan — which aimed to launch coordinated shooting rampages or attacks in Britain, France and Germany — is an al-Qaida hallmark.

U.S. officials declined to reveal what evidence they have that bin Laden took a more prominent role in this plan. But the involvement of bin Laden and his leaders, believed to be in hiding in Pakistan, underscores continuing U.S. concerns about that country’s role as a safe haven for al-Qaida and other Islamic extremists.

And it reflects al-Qaida’s persistent effort — through video and online messages — to inspire its followers to wage attacks against the West. The threat to Europe was highlighted when bin Laden issued a call to arms in March 2008 after a Danish newspaper printed controversial cartoons depicting the Prophet Muhammad. He warned Europeans in an audio message that there would be a “severe” reaction to come.

Rep. Pete Hoekstra of Michigan, the senior Republican on the House Intelligence Committee, said that bin Laden’s role in the European plot could suggest a lack of confidence by al-Qaida central in the ability of other affiliated groups in Yemen or Africa to carry out a successful attack on their own.

Over the past year, several terror attacks in the United States have either failed or been foiled, including the botched attempts to bring down a Detroit-bound airliner on Christmas Day and to set off a bomb in New York’s Time Square.

“They’ve let other people take the lead on attacking the West,” said Hoekstra. Bin Laden may now be thinking, “these guys can’t do it, we’ve got to become more involved again.”

A Pakistani intelligence official said Thursday that eight Germans and two British brothers are at the heart of the European terror plot, which is still in its early stages.

One of the Britons was killed in a recent CIA missile strike, he said.