Lol at anyone who thinks the is destroyed Iraq. Look around the region. There is no possible course of events the us or anyone else could have taken that would keep these people from trying to slaughter each other. We didn't invade Syria. Slaughter. We are the only thing that kept ghadaffi from wiping out half his country. Iraq was a shithole run by a tyrant, and now it's just a shithole run by no one. Like Syria. Like Libya.
The people who live in these countries are ignorant fanatics who still see the world through the lense of tribalism. Sunnis and Shia would be at each other throats even without our involvement.