how did one of america's closest allies become the home of its most bitter enemies? to understand, we have to go back almost 300 years. to the 1700s. two men formed an alliance in the arabian desert. a cleric known as mohammad bin ahab and a warrior named mohammad bin saud, patriarch of the saudi royal family. al ahab and his family were the isis of their time, preaching strict adherence to the koran on pain of death. their puritanical faith became known as wa habbiism. and it was that creed which dominated saudi arabia for years. >> authorities inside saudi arabia have executed -- >> wahhabism starts as a