Of the four narrative techniques described by Wesley Kort, the expository style of Capra seems to cater to plot and the appeal to truth is in the form of a testimony. Capra tended to present the march of Germany through Europe in Why We Fight, for example, as a succession of events. The closing moments of the film suggests that the story is not over and invites the audience (not unlike an alter call of sorts) to join the narrative, and change the outcome. The implication is that Nazism needs to be stopped, and the call to action is justified by the evils that the audience has just witnessed. Capra in this case wanted to paint in broad strokes, and offer a very clear moral or lesson in his films. However, by the mere fact that the films were intended as propaganda, there is a very real sense in which they gloss over the truth in many ways, painting history as completely one-sided and failing to deal with any of the nuances, moral dilemmas or doubts about war in general or human conflict. In some cases, Capra engaged in outright racism in what he thought was in service to the war effort by depicting the Japanese as “monkeys” and fundamentally flawed as a people (Know Your Enemy – Japan, 1945). Expository films often have their place and purpose, but due to their polemical nature, can sometimes tend towards manipulation rather than illumination.
– from the upcoming book “How to Film the Truth: The Story of Documentary Film As a Spiritual Journey” to be released in the Summer of 2018 by Wipf & Stock