WASHINGTON -- Intelligence officials believe Osama bin Laden's voice is on the audiotape played Tuesday by an Arab television station and that the underlying message of the tape is clear: Bin Laden is alive and well, and his al-Qaida network is poised to strike again.
"Assuming that these tapes are authentic as indications point to, I believe it shows that bin Laden is alive and that he's asserting himself and he's letting the street know -- his people all over the world -- and he's sending a message not only to us but to our allies that he's coming after us," said Sen. Richard C. Shelby of Alabama, the ranking Republican on the Senate intelligence committee.
While experts could not say with certainty yesterday that it is bin Laden on the tape, the United States and its allies are taking threats in the tape seriously and are braced for the possibility of another terrorist attack soon.
"Whoever put this tape out has put the world on notice yet again that we're at war and that we need to take these messages very seriously, and we will," said President Bush after a White House Cabinet meeting. "We'll take them seriously here at home by working with the appropriate authorities to deal with threats, and we'll take them seriously abroad by continuing our hunt."
CIA officials told Bush late Tuesday or early yesterday that the voice on the tape played Tuesday on the Arab-language Al-Jazeera network probably belongs to bin Laden, according to sources who spoke on condition of anonymity.
On the tape, bin Laden accuses Bush of "killing our sons in Iraq" and conspiring with Israel to bomb "houses that shelter old people, women and children with U.S.-made aircraft in Palestine."
The tape delivered a more chilling message to U.S. allies, specifically Britain, France, Italy, Canada, Germany and Australia: You may be next.
"You will be killed just as you killed, and will be bombed just as you bomb," the tape says. "And expect more that will further distress you."
Intelligence officials said the countries mentioned on the tape should be very concerned because bin Laden has a history of telegraphing his moves and following through on them.
"I think there's good reason for everybody to worry, but I think it would be higher up in the worry list if you were a named country," said a senior Bush administration official with direct access to CIA files.
Brian Jenkins, a terrorism expert for the Rand Corp., a California-based think tank, said it is a "reasonable assumption" that the tape is authentic and the voice is bin Laden's.
"It's vintage bin Laden when you compare it to previous messages," Jenkins said.
A counterterrorism source and former National Security Council official knowledgeable about bin Laden said the tape means "something will come up soon."
In Ottawa, where Secretary of State Colin L. Powell is scheduled to meet with Canadian Foreign Minister Bill Graham, officials said they view the tape's message as a legitimate threat.
"This indicates the global nature of the terrorist threat, and we're looking at it with seriousness," said Foreign Ministry spokesman Rodney Moore.
However, the tape did not spur the Bush administration's Office of Homeland Security to raise its terrorism threat level above the current Code Yellow, the third of five danger rankings.
"We're not moving the national threat level; the type [of threat] isn't that specific," said spokesman Gordon Johndroe.
Bush's national security adviser, Condoleezza Rice, told the Trotter Group, a group of black columnists, that linguists have told administration officials that they believe the voice is bin Laden's, but that they can't be 100 percent certain.
"There is a lot of technical work that has to be done to look at what happened to the tape and so forth," she said in an interview with the group.
Technical experts said they are working with a poor-quality audiotape that might have been recorded and re-recorded several times to cover bin Laden's tracks, intelligence sources said.
"He records a statement on tape," the former NSC official said. "The tape is then brought by a trusted emissary, a courier, to a second place. The second place then plays the tape over a phone line to a third place, which records it, and maybe edits it, and it's given to another person to begin a chain of communications. It's done to insulate bin Laden."
William Douglas and Knut Royce are reporters for Newsday, a Tribune Publishing newspaper.