As late as April 26th David Petraeus promised that we would know whether things were working out by September:

General Petraeus said he and the American ambassador to Iraq, Ryan C. Crocker, intended to stick by a vow to offer the White House and the Pentagon an assessment of the progress of the new strategy by early September. And he signaled that he hoped for political progress in Iraq, not just military improvements.

''We'll have seen whether in fact our efforts in these areas have helped produce the kind of progress that they are designed in fact to produce,'' he said. ''One would certainly hope that the Iraqi legislators would match that with their own hard work. That's our expectation.''

(from the New York Times, "US Commander Says Fall Pullback in Iraq Would Lead to More Sectarian Killings", by David S. Cloud and Michael R. Gordon, April 26th)

Well, I prefer honesty to being told what I want to hear. OTOH, I don't believe the Pentagon or White House operates in this way.