Errol Morris, long one of the most distinctive stylists in the world of documentary filmmaking, has finally done something I never expected him to do: he's allowed his style to trump all substance, releasing his first unnecessary film.

In the past, Morris has made quite a name for himself as a chronicler of the offbeat and unexpected: a pet cemetery in Gates of Heaven, the life and theories of physicist Stephen Hawking in A Brief History of Time; even his first overtly political film, The Fog of War, took a rather unusual approach to the subject of American military action, focusing on the methods and madness of the rather unusual warmonger Robert McNamara. In his latest, Standard Operating Procedure, Morris takes on the atrocities at the Abu Ghraib prison in Iraq. You may have heard something about them

The problem isn't exactly that in SOP, the filmmaker chooses for his topic a subject that has been covered in several films and countless news reports - at worst, that's a mere disappointment. The problem is that his treatment of the material is just about as shallow as it could possibly be. Focusing primarily on the infamous photographs of Army MPs subjecting Iraqi prisoners of war to degrading abuse, Morris interviews as many of the people in those images as he could find - from the notorious Lynndie England to mostly unknown figures like Jeremy Sivitz. The stories tend to sound alike, something the lines of "It felt wrong, but that was what it was like over there." And in the face of such sweeping vagueness, Morris punts.

Oh, what has happened to the director of The Thin Blue Line, that filmmaker who poked at every story and every witness until the truth outed itself? That he should now be so delighted in taking at face value the non-apologias of men and women who freely admit to breaking all number of moral taboos, some of whom don't even seem particularly bothered by it! If you sat Errol Morris down and asked him why he did so, I'm sure he'd mention something about the soldiers on the ground being the symptom, the disease is Rumsfeld and company, their willingness to overlook - encourage! - systematic torture. Which would certainly be a defense, if only Standard Operating Procedure covered that ground. Even then, it wouldn't be a particularly excellent defense in light of films like the superlative Ghosts of Abu Ghraib, which already looked at those connections in sickening detail.

No mistake, it looks like an Errol Morris film: by far the most common sight in the film is an interviewee staring straight into the camera, cutting to the same interviewee staring into the camera on the other side of the frame! I mock, but I actually do love the Morris style; it is intimate and hypnotic enough to make those Jeff Goldblum Mac ads seem like the highest form of art. Far more problematic is the film's extensive re-enactments; apparently figuring that hundreds (literally) of Abu Ghraib torture photos weren't going to be enough to get the audience, the director dramatises some of the stories as the soldiers tell them, so that instead of seeing an actual soldier actually torturing an actual Iraqi, we watch an actor playing a soldier pretend to torture an actor playing an Iraqi. It's almost certainly hyperbole to claim that this cheapens the real photos, but it certainly doesn't do them any good.

So caught up is SOP in gorgeously nasty looking re-creations (shot, I think, by Robert Richardson) and stately interrocam shots (shot by Robert Chappell, presumably - the film credits both cinematographers by name, but goes no further) that it forgets to have an argument, other than simply presenting the photos in a very bland "this happened" sort of way. There's no shortage of places to go in this world that present the photos and draw conclusions, and Morris's film just comes across as shallow as a result.

But...but, but, but. There is one thing in Standard Operating Procedure that works like gangbusters. By focusing most of the attention to the most famous photos - England holding a prisoner by a leash, England watching prisoners masturbate, Sabrina Harman flashing thumbs-up next to a corpse - and allowing multiple witnesses to recall the backstory to that photo from multiple points of view, the director occasionally reaches something like genius. At its best moments, SOP asks us to consider the precise nature of photography, capturing the truth but only the truth of a single instant, a truth which extends beyond the edge of the picture. We all know the Abu Ghraib photos, the film states, but that doesn't mean we know what happened in Abu Ghraib, in its totality. The ambivalence about the meaning of the photograph as a news-bearing element is something that I haven't seen in a movie like this, and during these moments, that old Errol Morris magic kicks in. Admittedly, we have to meet the movie a bit more than halfway - we practically have to hop in the car, drive to the next town over, and knock on the movie's front door - but it's in there, and it's great, even if it reduces one of the truly horrifying controversies in American military history to an intellectual puzzle.

All in all, it's a movie without a soul, and sometimes without a brain. Speaking as one who awaits a new Errol Morris picture with something akin to a child counting down to her birthday, this pains me to say. But a single misstep isn't going to end his career, and I respect the impulse that drove the director to make the nth Iraq doc out there, even if I can't get particularly exercised about the result.