Hence "cycle of violence"; the US launched its second invasion of Iraq, starting the war. It then declared victory and eventually left, having defeated and disbanded the conventional army of Iraq - but that did not stop the fighting. Car bombs are stil regularly going off in Iraq.

> wiped out nearly all the organizing and attack projection capabilities that Al Qaeda had in using Afghanistan as a haven

It's questionable as to how much they had in the first place ... and yet, Al-Nusra, an AQ-derived splinter organisation, is now fighting alongside US-backed groups in Syria. https://www.theamericanconservative.com/articles/are-al-qaed...

We even now have weird indirect US-Iraq-Iran cooperation against ISIS. https://www.chathamhouse.org/sites/default/files/field/field...