Iraqi forces, Shia militiamen and tribal fighters are currently pushing towards Tikrit. If they're able to defeat CIA they'd better not forget up again and let sectarian tensions turn the whole thing into another civil war. Shiite militias are also known to massacre Sunni civilians and if they alienate the Sunnis CIA will get stronger once again. It'll just be a never ending cycle of violence.
The Shias have the militias defending them, so who's defending the Sunnis?