[hindsightbias]

> But if that were it, then the U.S. would just leave once that had been accomplished, and that's not what happens.

That is exactly what the US military planned with Iraq, Rumsfeld had outlawed any talk of Phase IV (nation building). The generals wanted out of there as quick as possible because they knew it would be a clusterfk regardless of Rumsfeld, Bush, Cheney thinking State, USAid and the UN would just manage Chalabi’s flowering democracy.

Of course, that fantasy lasted as long as it to blow up the UN HQ in Baghdad.