The Prelude to War can be classified as a documentary. Firstly, because the film has been recorded or created frame by frame. Secondly, it is a record of real events in the world, rather than the world completely imagined by the creator. Finally, it is presented to the audience, film festivals or critics as a documentary by its producer.
Bill Nichols writes that the the documentary ‘is depended on the specificity of its images for authenticity’.
By using animation, the film not only expresses the record of objective and real events, but also conveys symbols, visual associations, colors and other information.