hi friend look late me tall you with my experience first politic because this subject it is more politic than be religious and also give you my experience in islam
first the islam it is not religion order to kill for we be clear .
so bin laden he not was man of religion for he use they taught sound islamic theology.
osama bin laden he was influenced by mullah mohammad omar, a very radical manosama bin laden's little understanding of religion has made osama bin laden's speech radical and deviated from the teachings of islam
so the answer > they used radical persuasive rhetoric