According to documents obtained by NEWSWEEK, Al Qaeda mastermind Khalid Shaikh Mohammed told U.S. investigators after his capture last year that a high-ranking Qaeda lieutenant known as Khallad originally was "selected" to participate in the 9/11 attacks as a "bouncer"--one of the musclemen assigned to corral and subdue passengers on a hijacked plane. Khallad, a one-legged Yemeni also known as Tawfiq bin Attash, attended a January 2000 "summit" meeting in Malaysia at which he allegedly went over plans for 9/11 with two future hijackers, Khalid Almihdhar and Nawaf Alhazmi. After the meeting, Almihdhar and Alhazmi traveled to the United States....