We started this mess. Recall that we were told that after we get rid of Saddam, that Iraq will become a shinning example for the rest of the ME, and the world. That the guy was such a bad guy that the world will be a far better place without him.
https://en.wikipedia.org/wiki/Sykes%E2%80%93Picot_Agreement
It is, of course, easy to be wise long after the event.