Osama bin Laden publicly quiet for longest stretch

~ Counterterrorism experts ponder the implications of his silence.

WASHINGTON -- Osama bin Laden, known for his fiery public statements, has been publicly mum for the longest stretch since the suicide hijackings on Sept. 11, 2001.

That leaves U.S. counterterrorism experts questioning what, if anything, his silence means.

The al-Qaida chief with a $25 million U.S. bounty on his head issued two audio statements in December, his last known public words.

He was last seen on a videotaped message to Americans on Oct. 29, 2004, saying the United States could avoid another Sept. 11 attack if it stopped threatening the security of Muslims.

"Any state that does not mess with our security has naturally guaranteed its own security," bin Laden said in a translation of an address aired on the Al-Jazeera network discussing the 2004 presidential elections.

Since the Sept. 11 attacks, the longest bin Laden had gone without issuing a new public statement -- audio or video -- was just over nine months. He has now let 10 months pass.

Two U.S. counterterrorism officials, speaking on condition of anonymity because of the subject's sensitivity, said there is no evidence to suggest bin Laden is dead. The working assumption is that he is alive, even if he isn't churning out tapes.

Ben Venzke, chief executive at the IntelCenter, a government contractor that does support work for the intelligence community, said terrorism analysts are paying attention.

'A PR strategy'

"This is the first time things have changed in years. Messages have generally come in a consistent pattern, and now they are not," Venzke said. "It is likely that these changes in messaging by al-Qaida are the result of planning and a PR strategy, as opposed to their computer broke."

Venzke noted it was also the first October since 2002 that bin Laden had not delivered a message addressed specifically to Americans.

The terror leader is believed to be hiding in a rugged area along Afghanistan's border with Pakistan, where the Pakistani government has little control and tribal loyalties run deep.

Venzke notes there could be a number of factors contributing to bin Laden's public silence. He may have decided to change the messenger. His deputy, Ayman al-Zawahri, has been much more vocal, issuing seven messages this year. In years past, he and bin Laden delivered roughly the same number of messages.

Or the earthquake in Pakistan could have inhibited bin Laden's ability to transmit messages. Or a tape could have been destroyed in the rubble. Yet, al-Zawahri has managed to send out a message since the earthquake, calling on Muslims to provide aid.

Bin Laden also could be plotting an attack on the United States and has made a strategic messaging decision to keep quiet in the lead-up to the attack, Venzke said.

In a recent interview, the head of the National Counterterrorism Center, retired Vice Adm. Scott Redd, said bin Laden can't communicate with his followers the way he had in the past.

"The more you communicate, the more you try to directly run an organization, the more vulnerable you are," Redd said. "And he is pretty deep in hiding. We know he is not communicating very much."

President Bush rarely mentions bin Laden, who has eluded U.S. capture despite being the most-sought terrorist in the world. Bush did mention him by name in a series of speeches focused on the war in terror last month.

Half of Americans think it's likely that the United States will capture or kill bin Laden, a number that has moved little over the last three years, according to a CNN-USA Today-Gallup poll.