Alexis Debat discusses that intriguing question:

Osama bin Laden’s tapes — like his operational directives — are hand carried from courier to courier in a long and intricate route that involves several dozen “runners.”

According to al Libbi, it takes six to 12 weeks of travel in the remote and inhospitable areas along the border between Afghanistan and Pakistan, where bin Laden and Ayman al Zawahri are still hiding. Based on this piece of intelligence, the Pakistani government succeeded in infiltrating parts of these courier networks in 2005.

But because of the extraordinary precautions taken by al Qaeda’s messengers, the Pakistanis were unable to trace them back to either Zawahri or bin Laden.

The system involves each courier hand delivering the tape or the written message to another courier or location without knowing the courier’s identity, the origin of the tape or message or its destination. It makes it almost impossible for intelligence agencies to roll up the entire network.

Some of these intermediaries are recruited among the thousands of travelling Muslim preachers who roam Pakistan’s tribal and northern areas, usually on foot.

Analysts believe this system is still in place today, and may span several countries. According to a senior Pakistani intelligence source, the latest tape was hand delivered by an anonymous source to al Jazeera’s Dubai bureau in the United Arab Emirates.

Hat tip to Andrew Cochran.

The same article in Counterterrorism Blog reveals that the supposedly “new” Zawahiri tape is a recycled older one. This fact provokes the suspicion that perhaps the CIA Predator strike might have really bagged Al Qaeda No. 2 after all, and efforts are being made to conceal the US success.