In our historical effort from the Iran Iraq war in the 80's to our decade long occupation, our mismanagement of the reconstruction of Iraq and Reorganizing of Iraq's government and military has accomplished the exact opposite of what we set out to do.
Now Iran has a foothold here and combating ISIS is the door for them to access and expand influence in Iraq.
This is the same exact state tactic we used in 2003 with weapons of mass destruction to access Iraq directly.