…I offer this.
Do the Iraqi people deserve this, just because they failed to get along together and turn into a well-functioning democratic state in a decade (less than that, actually, before we pulled out)? Remember also that not all of these murderous marauders are homegrown Iraqis. Some came to Iraq attracted by their correct perception of that country’s weakness bereft of the last vestiges of American protection.
The world is full of barbarism, and we can’t even begin to stop it all. But there is no excuse for our complete pullout so relatively soon after helping to establish a new government in Iraq.
[NOTE: And since Iraq/Vietnam connections keep coming up, the barbarism of the forces taking over Iraq today makes me think of our current Secretary of State John Kerry's long ago charges slandering American servicemen in Vietnam. This video can't be embedded, but it's well worth watching.]