At the beginning of the documentary, Rumsfeld argues that a major purpose of the Department of Defense is to evaluate "unknown unknowns," or "the things you think you know, that it turns out you did not," to anticipate hostile actions before they take place.
As the interviews proceed, the director is able to catch his subject lying on camera, though when he does, Rumsfeld does not acknowledge it, with Morris finding the politician unwilling or unable to engage in self-reflection [REF].