ISIS would not even exist in Iraq if Saddam was still in power.
Just saying...
War rarely proceeds along logical paths and the outcomes are often unpredictable and long-lasting.
ISIS did exist in Iraq when Saddam was in power as did ANO, Abu Nidal’s group. It just had a different name then just as it is trying to change its name now to ISIL.
AlQaeda also existed in Saddam’s Iraq- Saddam Hussein’s regime gave safe harbor, a pension and a house to one of the conspirators in the 1993 World Trade Cennter bombing and also took in one of the conspirators in the USS Cole bombing who had attended the Malaysia terror summit where the attack was planned on the ship in January 2000.