Al - Hassan is the son of a teacher . ` ` He used to write letters to his mother '' his uncle says . The two issued a fatwa , or decree , that said , `` The judgment to kill and fight Americans and their allies , whether civilians or military , is an obligation for every Muslim . '' He became involved in Islamic terrorism as a teenager . He joined forces with bin Laden during the Soviet invasion of Afghanistan .
Al - Hassan is the son of a teacher . ` ` He used to write letters to his mother '' his uncle says . He became involved in Islamic terrorism as a teenager . He joined forces with bin Laden during the Soviet invasion of Afghanistan .