Arab unrest is shaking the foundations of US counter-terror efforts that have long relied on spy agencies under authoritarian regimes to help fight Islamist militants.
With popular protests toppling rulers in Tunisia and Egypt and threatening leaders in Yemen and elsewhere, US intelligence agencies are struggling to adjust to a radically changed landscape, US officials, former intelligence officers and experts say.
The United States for years has counted on Arab allies to back up its diplomatic and security interests, enlisting their help to combat al-Qaeda with harsh tactics and interrogations.
But the political wildfire spreading across the region means US spy services will have to deal with new intelligence chiefs more wary of Washington and more reluctant to cooperate on covert projects that might be unpopular with their citizens.
"The immediate effect, there's no question, is that a lot of relationships which we have built over the years to fight al-Qaeda and like-minded terrorists are over," said Bruce Riedel, a former CIA officer.
Key figures who became trusted partners for American intelligence services such as Omar Suleiman, Egypt's former spy chief, are now gone and their successors will likely be less willing to do Washington's bidding, said Riedel, a fellow at the Brookings Institution.
US officials are most alarmed at the fallout from upheaval in Yemen, where al-Qaeda has already exploited a a violent power struggle between President Ali Abdullah Saleh and his opponents.
"The focus of Yemeni intelligence is not on al-Qaeda anymore, it's on surviving and figuring out who's going to be the next boss," Riedel said.
Anxious to see an end to protracted unrest, President Barack Obama's administration has dropped its support for Saleh, urging him to peacefully hand over power.
Even if some semblance of stability is restored in Yemen, al-Qaeda will have emerged stronger, raising the threat of another attack on Western targets by the network's affiliate there, Riedel said.
"Their safe-haven, their sanctuary is probably going to be safer and bigger when this is all over than it is now.
"And that means the threat not only to the US but to Europe is going to go up as well," he said.
A US official acknowledged that the turmoil offered "opportunities" for al-Qaeda's branch in Yemen, which has tried to blow up an airliner and cargo planes bound for US cities.
