Clarke was involved in supervising the investigation of Ramzi Yousef , one of the main perpetrators of the 1993 World Trade Center bombing , who had traveled to the United States on an Iraqi passport . Yousef is the nephew of Khalid Sheikh Mohammed , a senior al-Qaeda member . Many in the Clinton administration and the intelligence community believed Yousef 's ties were evidence linking al-Qaeda 's activities and the government of Iraq
1993 World Trade Center bombing
1993 World Trade Center bombing
Richard A. Clarke