Matthew Yglesias again:

To go stronger here, it’s worth observing that absolutely integral to starting to achieve success in Iraq was the rolling strategic decision to abandon our main war aims. In particular, we’re now neither trying to create a strong Iraqi state, nor trying to create an Iraqi state that isn’t dominated by pro-Iranian forces, nor trying to create an Iraqi state that’s a base for American military power, nor especially trying to create a stable Iraqi democracy. I think all of those decisions were the right decisions, based in smart pragmatic thinking about Iraqi realities and American interests. But if we didn’t want to do that stuff, that we could have just not invaded in the first place. Which is exactly what we should have done!

(emphasis original)

Too true.