Complex sentence: Shia Iran and Wahabbi Saudi Arabia, as competitors for regional hegemony, encouraged violent conflict among two other factions, respectively the Shia Hazara Hezb-i Wahdat of Abdul Ali Mazari and on the other side the Sunni Pashtun Ittihad-i Islami of Abdul Rasul Sayyaf.
Split into simpler sentences: Shia Iran and Sunni Wahabbi Saudi Arabia as competitors for regional hegemony encouraged violent conflict among two other factions. On the one side was the Shia Hazara Hezb-i Wahdat of Abdul Ali Mazari and on the other side the Sunni Pashtun Ittihad-i Islami of Abdul Rasul Sayyaf.