This interrogation is not a pleasant sight. We see a lone teenager put under pressure by a skilled questioner who shows apparent concern for his well-being, mixed with bellicose entreaties that he should be honest and go back on his story, a crude but often effective approach. The interrogator has built a relationship of sorts with his captive. He is playing to the suspect's self-esteem as someone who is too good at heart to tell a lie unless he avoids the other person's eye. The deliberate analogy is with a parent who confronts a mischievous child and says: "Look me in the eye and tell me the truth and all will be forgiven."

We have no way of knowing how the suspect has been treated since his capture, and this tape gives us no more than a glimpse of his experience. We remain ignorant of all the important facts which would be part of a normal legal case, and are given a snapshot of a man in psychological distress. If one thing stands out, it is the dog that could not bark because it was not present: Omar Khadr needs a lawyer by his side.

However, I wonder if our viewpoint might change if the teenager was accused of having knifed another child to death. Despite ourselves, we might be on the side of the interrogator seeking confession and contrition. The hectoring of an isolated teenager is a recipe for unsafe convictions. However, at perceived moments of historical crisis all Inquisitions seek The Truth by means of torment. The real psychological question is whether we can remain humane when faced with avowedly inhumane opponents.

The writer is a clinical psychologist at University College London