To get around being badly wrong on a major policy, many policymakers and analysts will insist on judging policies by the supposed intentions of their authors and not by their results.
Peter Beinart and, say, Andrew Sullivan, are among the few public commentators who supported the Iraq War, abandoned that position, and then publicly held themselves accountable for it—why they changed their minds, what assumptions and premises they held going in, what they got wrong, what they got right, how they would think differently now in a similar debate. It was important exercise, but it didn’t exactly go viral. As for the other 99.9%, well not so much.
There’s an amazing disconnect in public between the consensus view of the failure of the Iraq project and the broad tacit acceptance of the correctness of all the premises and arguments that got us into it.
It’s treated as if going in wasn’t a choice at all. We merely did what had to be done and therefore there’s nothing to be learned from the fact that it turned out badly.
Of course Our Foreign Policy Establishment is learning.
Whether in or out of government, not one of the cheerleaders for the War on Iraq suffered in the slightest, neither personally nor professionally. In fact, many are still in power, and are regularly hailed as Serious Thinkers, Foreign Policy Experts and Hard Headed Realists, even though not one of their rosy predictions for the war came to pass.
Meanwhile, those who argued against the war were cast into Outer Darkness, even as the war proved more disastrous than even the most pessimistic of naysayers would have had it.
Sociopaths learn only from reward and from punishment, but they do in fact learn.
This is a good article that gets into greater depth and provides some analysis as to why the foreign policy establishment behaves the way it does.