By accident of geography, the world's major oil resources are in Shi'ite-dominated areas. Iran's oil is concentrated right near the gulf, which happens to be an Arab area, not Persian. Khuzestan is Arab, has been loyal to Iran, fought with Iran not Iraq during the Iran-Iraq war. This is a potential source of dissension. I would be amazed if there isn't an attempt going on to stir up secessionist elements in Khuzestan.