What mistakes did the united states make in the immediate aftermath of the invasion of iraq which lead to the sunni led insurgency

During the Bill Clinton administration, no-fly zones in the north and south of Iraq kept Saddam’s aircraft grounded in an effort to protect the Kurds and Shias. In February 1998, Secretary of State Madeleine Albright confirmed that U.S. strategy toward Saddam was containment, arguing that removing Saddam would be too costly and that fomenting a coup would create false expectations.6

If i’m not mistaken your answer should be the freemen’s bureau started them. i really hope i could ! good luck