"Iraqies have killed far more of their own people than the americans ever have"
That can be traced pretty directly back to mistakes made by U.S occupying forces shortly after the invasion. The looting may have not seemed like much at the time, but the fact that the U.S a) fired all the police, soldiers, and officials who could have stopped it, and b) stood by and didn't stop it themselves meant that the people had to do something about the crime which quickly spread to their own neighbourhoods on their own. The only organisations with a wide reach not disbanded by the U.S administration were the mosques and the Islamic clerics, who immediately became the de-facto local government.
I hope you can see from there where it went (with anti-occupation guerillas and the entry of foreign terrorists into the picture) without me drawing you a picture. Further stupid actions by U.S occupiers were basically a textbook case in "how to create a civil war".
Meaning that it is indeed the United States which has caused the situation in Iraq, and thus is responsible for it, and the resulting deaths, injuries, and misery. Denying that is much like tossing a baby into a lion cage and claiming innocence.
America broke the country. Permanently, it seems.