Why is our own government putting out so many reports contradicting general Petraeus' report?

why is the news being reported by the media also conflicts with the generals report? I speak of pentagon reports, general accounting office reports, white house reports, and of course the daily stream of negative news as in inations, car bombings, maliki government losing support, blackwater incident, etc.. is there a conspiracy from the left to discredit the brave and honnest general?