Complex sentence: Western peoples, whom the ideology of Orientalism had defined as weak societies and impotent countries; the geopolitical reality of their actions, of military and economic warfare, voided the fictional nature of Orientalist representations, attitudes, and opinions about the non-Western Other self.
Split into simpler sentences: Western peoples, whom the ideology of Orientalism had defined as essentially weak societies and impotent countries. The geopolitical reality of their actions, of military and economic warfare, voided the fictional nature of Orientalist representations, attitudes, and opinions about the non-Western Other self.