To be honest, I was a little disappointed in Standard Operating Procedure...but the fault is my own, not the film's. My expectation was that the film would start with the photos of Abu Ghraib & misdeeds of the lower ranking soldiers and then move up the chain of command, both militarily and thematically speaking, to explore the issues of truth in photography and culpability. To Morris' credit, he didn't do that. It's too easy these days to attempt arguments about Iraq or the Bush Administration that connect too many dots with too little evidence...essentially propaganda that sings to the choir.
SOP has a surprisingly small depth of field; it's the story of those infamous photos, the people who took & appeared in them, and what they have to say about the photos & the actions they purport to show. And in that, the movie succeeds. Morris leaves plenty of negative space into which the audience can insert their own questions about what the photographs ultimately depict and who's responsible in the end.
Incidentally, Morris generated a bit of controversy recently when he admitted that he'd paid some of the interviewees in SOP. The criticism of this practice is that "the credibility of interviewees diminishes when money changes hands and that these people will provide the answers they think are desired rather than the truth". That is a concern but no more so than every other reason for being untruthful, including not telling the truth out of spite for lack of payment. People have so many better reasons to lie than money.