Al Qaeda’s As-Sahab media arm released a video Sept. 11 to commemorate the sixth anniversary of the 9/11 attacks. Although the 47-minute video features a voice-over introduction by Osama bin Laden, the bulk of it is of Abu Musab Waleed al-Shehri, one of the suicide bombers who crashed American Airlines Flight 11 into the World Trade Center’s north tower. That recording was made prior to al-Shehri’s travel to the United States in the spring of 2001....