The Unknown Known plays at the Sydney Film Festival on 5 and 8 June. Patrick Hurley works for the London-based documentary film distributor Dogwoof, which is releasing the film.

Fans of the Academy Award-winning documentary The Fog of War: Eleven Lessons from the Life of Robert S McNamara (2000), will no doubt be looking forward to the director's second film featuring a US Secretary of Defense, The Unknown Known, which will have its Australian premiere this week as part of the Sydney Film Festival.

For reasons he does not divulge, Donald Rumsfeld (who reportedly hated The Fog of War) agreed to spend 33 hours in front of Errol Morris' unique and ingenious camera contraption, 'The Interrotron', resulting in another spectacular film where the interview-subject is looking directly in to the camera throughout.

In The Unknown Known, Morris asks Rumsfeld to recite and contextualise selected memos from the tens of thousands he penned over the course of his career. The memos, or 'snowflakes' as they are called, range from high-level strategy recommendations to the president to spontaneous instructions to his assistants requesting dictionary definitions for particular words. They offer a window into the mind of Rumsfeld and are used as the building blocks for the film. It is off the back of Rumsfeld quoting himself that Morris seeks explanations and justifications.

Rumsfeld's responses are perhaps predictable, but no less shocking. He gleefully embraces contradictions and responds to Morris' questioning with riddles and paradoxes. Throughout the film he appears to be enjoying himself, as if he's playing a game. While at Princeton and during his days in the navy, Rumsfeld was a champion amateur wrestler, captain of the varsity team and Olympic hopeful. He seems to treat the interview with Morris like a sporting match too. There is one moment when he eloquently puts a 'different cast' on Morris' reference to the 'so-called torture memos'. Here, Rumsfeld does not change the subject, rather he re-frames the memos in question as being 'blessed by the Attorney General'. With a familiar grin, he gestures to an invisible scoreboard and says 'I'll chalk that one up'.

Many reviewers of The Unknown Known have also interpreted the film as a sporting match and concluded that in the end 'the slippery bastard wins the day.' Morris is criticised for not being tougher on Rumsfeld, for not delivering more punches. I find this response to the film at best myopic, if not pernicious.

Unlike McNamara, who had eleven lessons to share from his days as a diplomat, Rumsfeld's reflections on history are downright cavalier. When asked by Morris if there was any lesson to be learned from the Vietnam War, Rumsfeld's response is 'some things work out, some things don't. That didn't.'

It is certainly frustrating that Rumsfeld doesn't have more to offer. Indeed, unlike his predecessor, Rumsfeld does not acknowledge mistakes nor show any signs of remorse. Reacting to this, many have concluded that the new film is inferior and that on this occasion the director failed to get to the truth. I suppose this interpretation is easier to swallow than facing the genuinely terrifying alternative possibility that Rumsfeld commanded the greatest military force on the planet without giving it too much thought. The great irony though is that the popular belief that Rumsfeld must be hiding something mirrors the Secretary's own blind certainty that Saddam possessed WMD. After all, 'an absence of evidence isn't evidence of absence'.

While Rumsfeld himself doesn't provide much in the way of an explanation for why the Iraq War happened, I would argue that the popular view that he somehow 'wins' in The Unknown Known is revealing in its own right. Somehow we have found ourselves in a situation where interactions between politicians and the public are frequently treated like a game (and a zero-sum one at that). The concerning thing, however, is that in this game non-answers count for points. The official can be asked a question, not answer it, and still walk away a winner. This happens all the time. But when guys like Rumsfeld walk away from the interviews they do stuff, like starting wars. As long as this culture that chalks up non-answers as points persists, we will continue to end up in debacles that we struggle to make sense of, and many will suffer as a consequence.

At a recent Q&A screening in London, a young man expressed his disappointment with the film, wishing that there was 'more sword-fighting'. Morris wearily elaborated that his approach to the interview was deliberate and considered. Another dissatisfied audience member piped up: 'Yeah, but who won?'. Morris responded with a scenario that doesn't exist in sport: 'I think we all lost.'

The film and its companion essay by the director are essential and urgent.