Given enough time and motivation, smart people will eventuallly figure things out. I think that’s what’s happening now in terms of identifying what went wrong in the time before, during, and immediately after the “major combat operations” phase in Iraq, such that we’re in the mess we’re in now.
See, for example, George Packer’s lengthy but excellent article in the latest New Yorker: War after the war. What Packer presents is the detailed back-story that confirms what seemed like a pretty likely explanation all along: that the neocons who sold the war to Cheney & Co. (or, if you prefer, to Bush & Co.) let their ideological zeal blind them to the advice of people who had a much clearer idea of the likely nature of the post-war challenge.
Ignoring the advice of experts because you have a compelling vision of the future that their hidebound expertise prevents them from seeing can sometimes be a good thing. But there has to be a balance. Taken too far, you get what we have now in Iraq: a slow-motion clusterfuck brought on by ignorance, arrogance, and hubris.
Which is nothing new. It’s human nature, after all, for the ambitious to oversell their abilities, for their reach to exceed their grasp, and, when things subsequently go bad, for them to refuse to acknowledge their responsibility for the result.
Feith, Wolfowitz, Rumsfeld, Cheney, Bush: they gave it their best shot. But their best shot wasn’t particularly good. In fact, it was pretty much awful. As time goes by that fact becomes harder and harder for them to obscure.