Although they both are major Muslim majority countries and they both follow Islam very strictly. But they fiercely oppose each other. In fact, they consider each other as enemies. Saudi Arabia is more of a Sunni Muslim and Ahle Hadees majority country and Iran is a Shia Muslim country. Saudi Arabia follows a monarch based system while Iran follows the democratic system. But the supreme leader in Iran is above the democratic system and can't be changed. However, who will claim dominance in the Middle East?