Reports of credible terrorist threats against the United States are at their lowest level since the attacks of Sept. 11, 2001, according to U.S. intelligence officials and federal and state law enforcement authorities.
The intelligence community's daily threat assessment, developed after the terrorist attacks to keep policymakers informed, currently lists, on average, 25 percent to 50 percent fewer threats against domestic targets than it typically did over the past two years, said one senior counterterrorism official.
A broad cross section of counterterrorism officials believes that al-Qaida and like-minded groups, in part frustrated by increased U.S. security measures, are focusing instead on Americans deployed in Iraq and on Europe.
Though some are expressing caution and even skepticism, interviews last week with 25 current or recently retired officials also cited progress in counterterrorism operations abroad and a more experienced homeland security apparatus for a general feeling that it is more difficult for terrorists to operate undetected. The officials represent federal intelligence and law enforcement agencies, state and local homeland security departments and the private sector.
"We are breathing easier," said U.S. Capitol Police Chief Terrance Gainer, whose officers guard one of al-Qaida's expressed targets, and who is regularly briefed by the FBI and CIA. "The imminence of a threat seems to have diminished. We're just not as worried as we were a year ago, but we certainly are as vigilant."
"I agree," said John Brennan, acting director of the National Counterterrorism Center. "Progress has been made."
Brennan also said the initial post-Sept. 11 belief that there were large numbers of sleeper cells in the United States turned out to be "a lot of hyperbole." Some people believed "there was a terrorist under every rock," he said.
But some intelligence analysts caution that the drop-off in terrorist-related planning, communication and movement could be a tactical pause by al-Qaida and related terrorist groups. No one suggested that the threat has gone away.
Brennan and others fear most what they are not hearing or seeing, especially the possibility that al-Qaida has acquired chemical or biological weapons and adapted in ways that have evaded detection.
Analysts also say a flood of new terrorists motivated by the U.S.-led invasion of Iraq may try to travel here and reverse the relative calm in the United States, as they are doing in Europe.
But for now, most officials acknowledged a change in perception, for the better. Most of these officials declined to speak on the record, for fear, as one put it, "that something will go boom" and the public will blame them for being complacent.