War in Yemen would hand al-Qaida's boldest militants greater scope to attack the West and repair the group's morale after the loss of Osama bin Laden, experts said.
With President Ali Abdullah Saleh's government mired in worsening political strife, the Yemen-based al-Qaida in the Arabian Peninsula, known as AQAP, is likely to have more freedom to apply a proven talent for daring and inventive bombing plots.
The small group — some estimates put it at 300 individuals — has nothing to do with a youth-based uprising seeking to end Saleh's long rule, or with opposition forces who fought pitched battles with his loyalists this week in the capital Sanaa.
Friday saw those forces make further gains when opposition tribesmen said they had wrested a military compound outside Sanaa from elite troops loyal to President Saleh.
Yemeni fighter jets could be heard breaking the sound barrier as they swooped over the capital, the scene of fighting between forces loyal to Saleh and the rival Hashed tribe led by Sadeq al-Ahmar, close to the Islamist opposition party Islah.
Tribes outside the capital said they were also fighting government troops at two other military bases.
White doves released
In Sanaa, tens of thousands of people gathered after Friday prayers for what they said would be a "Friday of Peaceful Revolution" against Saleh, releasing white doves and carrying the coffins of about 30 people killed in clashes this week.
But the turnout for the rally, inspired by the Egyptian and Tunisian revolutions, was less than previous weeks with many people fleeing Sanaa and the government closing roads around the capital to keep out tribes trying to reinforce the Ahmars.
Machinegun fire rattled across Sanaa and sporadic explosions were heard near a protest site where thousands of people demanding Saleh's departure are still camped.
Fighting in Sanaa eased off later on Friday after mediation efforts under which the al-Ahmar tribe evacuated government ministry buildings they had grabbed during clashes this week in return for a ceasefire and troops pulling out from their area.
"We are now in mediation and there has been a ceasefire between the two sides ... But if Ali Abdullah Saleh returned (to fighting) then we are ready. We are steadfast and victorious," Sadeq al-Ahmar told protesters in "Change Square."
"We wanted it (revolution) to be peaceful but Saleh, his sons and his clique wanted war. We will not leave them the opportunity to turn it into a civil war. There is mediation going on now," Ahmar told Reuters.
More than 40 Yemenis were killed in Sanaa on Thursday, the fourth day of clashes since the collapse of an agreement for Saleh to step down and bring an end to four months of unrest.
A complete collapse in state authority would worsen a host of ills of more concern to Yemenis than AQAP, including graft, crime, unemployment and failing water supplies.
But it is AQAP that is the West's top security concern.
Most intrepid attackers
It has international importance because it is al-Qaida's most intrepid community of attackers.
The group is adept at fielding operatives overseas, manufacturing and concealing sophisticated explosives, and producing compelling online propaganda that instigates attacks by others.
Its capacity to do all this from hideouts in remote regions in the provinces of Shabwa, Abyan, Jouf and Marib will grow to the extent that state security is distracted by political upheaval.
"Given how distracted Saleh's government is in its attempts to cling to power, AQAP has much more open space in which to operate at the moment," said Yemen scholar Gregory Johnsen.
A senior British counter-terrorism official said aspects of AQAP were "very troubling", including its ambition to strike outside its immediate neighborhood and what he said were its efforts to establish networks in East Africa and Europe.
"They've penetrated the global aviation system, they've got very competent explosives experts, seemingly we believe more competent than those of al-Qaida's senior leadership," he said.
The official said AQAP was operating "in a state which is failing and whose security apparatus ... has been diverted onto other matters, namely regime survival, creating areas of Yemen that are even less governed than they were a year ago."
Saleh told Reuters this week that al-Qaida had stepped up its attacks over the past few months but coordination with Washington in the fight against terrorism was going well.
Youths may join al-Qaida
Yet his critics say it is his misgovernment that has caused a range of problems including Islamist militancy, so much so that an end to his rule would be a gain for counter-terrorism.
"His continuation in power will only contribute to the underlying causes of al-Qaida to flourish in Yemen — lack of opportunity, corruption, cracking down on freedoms and rights, and killing Yemeni citizens in the name of fighting AQAP," Nadwa Al-Dawsari, head of Partners Yemen, a conflict prevention group working with tribal communities, told Reuters.
"If he stayed, the youth demonstrating now will be so frustrated they may want to join AQAP, or other groups engaged in smuggling, in gangs, in drug dealing and other social ills," he added.
Views such as Al-Dawsari's are widespread. But analysts caution that if Saleh is replaced, his successor will come under exactly the same pressure from the West to tackle al-Qaida.
Whether the current government's policies will be greatly altered by a new leadership is an open question.
Many feel more emphasis on improving governance in security and the judiciary would be better than the occasional U.S. missile attacks the government has allowed or tolerated.
"There is no magic missile solution to the problem of AQAP in Yemen," said Johnsen.
"If the U.S. continues to pursue strategies built solely around killing leaders of the AQAP without partnering that with a much more aggressive and nuanced development and political approach, then it will continue to reap short-term gains at the expense of long-term stability," he told Reuters.
