All we learned from the whole thing is that if you want to attack the USA, terrorism is the most effective way. A tiny investment will cause the entity to respond by working hard to abandon its own principles destroying itself, destroying thousands of others, and wasting unfathomable amounts of money.
This is as true now as ever.
Not to mention the tens of thousands of illegally detained, usually on fake or wrong pretenses, and the many of them tortured. Every one of them, and everyone that knows them, has every reason to hate the guts of everything remotely American.
(Edit: please observe all the downvotes, implicitly claiming that lives of Americans are somehow more valuable.)
Both are tragedies but both are different.
Low estimates of the cost of the Iraq war put it at 185k dead iraqi civilians.
I believe that it is much more likely that the US military simply doesn't care much about civilian deaths incurred whilst it seeks useless vengeance. This satisfies Occam's Razor, too.
How quickly a generation forgets the horrors of 9/11.