Arab satellite news network Al Jazeera and an Islamist Web site aired previously unseen footage Sept. 7 of Osama bin Laden and other high-ranking al Qaeda leaders apparently planning the 9/11 attacks. The video, like most other recent ones of al Qaeda leaders, was produced by the jihadist network's As-Sahab media branch, the fairly new organization behind the network's latest media blitz . In fact, banner ads appearing on extremist Web sites claim the video is a trailer for an upcoming As-Sahab documentary on the 9/11 attacks. In the absence of major attacks, As-Sahab has become al Qaeda prime's only means of making a strategic impact on the world outside of the Afghan-Pakistani border region. As-Sahab, which means "cloud" in Arabic, is a fitting name for a company whose operations are both fluid and nebulous. Videos of al Qaeda No.