Some are suggesting that things are looking up in Iraq, what with happier Iraqis, improved economy, the stronger state of the State and the increased oil production. Indeed this same some insist that nation building works. Others, which is to say me, ask if your life sucks 10 on scale of 1-10 with 10 being the most sucky and your rating changes to 7 your life still sucks. I'm not much good at math but I think that if your economy lay in ruins with a growth rate or, let's say, negative 20 and it went up to negative 10 that's a big improvement but still pretty sucky. And can a state really be called strong if it passes "impressive laws" but is unable to implement them? Also, too does it matter to whom the profits of the oil development go?
When the Nation-State developed over the course of the late 18th and most of the 19th centuries it consisted of two aspects: the Nation and the State. The Nation consists of those who see them selves or who can be convinced to see themselves as united by something. The State is the administrative arm of the government, which, ideally, reflects the interests and desires of the Nation, aka citizens. Because he conflates the two halves, Brooks can elide damaging structural weakness in one by pointing to temporary improvements in the other.
Even with this weak argumentative structure, when stripped of the high gloss, Brooks admits the State is too weak to fend for itself, barely capable of fulfilling its responsibilities, lacking necessary human capital, and generally speaking fragile. When discussing the Nation, he admits that the civil truce between Shia and Sunni is equally fragile. He has, in other words, defined success in a very odd way.
Finally, he leads off by claiming that the US spent 53 billion on this attempted nation building, when in fact the total cost of the war to date is 709 billion. He might maybe want to argue that 656 billion he fails to mention doesn't count but he ought to explain why.
Why is that when serious people think seriously about serious matters and make such serious errors in analysis, one wonders how they receive and maintain reputations for seriousness.
 A quick note to Conservatives and others trumpeting that fact the the invasion cost less than the stimulus: you're being silly and, I suspect, you know it.