In exchange for Jordan's return of the captured Mossad assassins, Israel released Hamas' spiritual leader, Sheik Ahmed Yessin , who had been imprisoned in Israel since 1989.
Jordan captured five Mossad assassins over a ten year period.  
mnli hypothesis: Jordan captured five Mossad assassins over a ten year period.   premise: In exchange for Jordan's return of the captured Mossad assassins, Israel released Hamas' spiritual leader, Sheik Ahmed Yessin , who had been imprisoned in Israel since 1989.