As he worked on the seven documentaries in the Why We Fight series, which he supervised for the United States government during World War II, producer-director Frank Capra wanted to create a potent antidote to the cinematic poison of Triumph of the Will, the celebration of Nazism made by German director Leni Riefenstahl in 1935. Riefenstahl had paved the way for "Hitler's holocaust of hate," Capra recalled in The Name Above the Title, his 1971 autobiography. Decades after Hitler's defeat, the thought of Riefenstahl's promotional film for totalitarianism still made his blood run cold.

Capra's wartime filmmaking was motivated by his fear - widely shared in the Allied countries - that the Nazis of Germany, the Fascists of Italy, and the militarists of Japan were about to "take over the free nations by force" and proceed to "stamp out human freedom and establish their own world dictatorships." He saw clear proof of this in the books, speeches, and films sent by those enemies into the world as weapons of ideological warfare.

The best way to combat their evil messages, Capra decided, was with the enemy's own tools. Fighting propaganda with propaganda, he would attack the distorted views of the Axis powers by splicing materials from their speeches, books, newsreels, and movies - including footage confiscated by the Treasury Department from German, Italian, and Japanese sources - into edited sequences that would reveal their malignant nature. "Use the enemy's own films to expose their enslaving ends," Capra declared. "Let our boys hear the Nazis and Japs shout their own claims...and our fighting men will know why they are in uniform."

The first of the films to be completed was Prelude to War, which Capra screened for General George Marshall, the Army Chief of Staff, in October 1942. Marshall gave the picture an instant rave review, and no wonder. According to film journalist Mark Harris in his 2014 book Five Came Back: A Story of Hollywood and the Second World War, the film was exactly what the military brass wanted: "an illustrated lecture in which animation, newsreel footage, narration (delivered with calculated folksiness by Walter Huston), and blunt language combined to strike a balance between history and rallying cry." The movie expanded Capra's conviction that the war pitted freedom against slavery into "a heartfelt American ideology" that was actually "more far-reaching than any that had yet been officially articulated as national policy."

Capra knew that the first audience for Prelude to War would be American soldiers, and he also knew that the surest way to win them over was to aim at their hearts rather than their minds, their emotions rather than their intellects. After a short introduction the film cuts to a montage of wartime destruction perpetrated by Axis forces - the attack on Pearl Harbor, the bombing of Britain, the invasions of France and China, and similar ugliness inflicted on Czechoslovakia, Poland, Norway, Belgium, the Netherlands, and on and on. Next comes a dazzling sequence showing American workers, machines, and factories churning out vital equipment for the war effort, replete with animation, superimposition, and eye-catching images.

The film then explores the question of how the free world established its freedom, giving the credit to a "long and unceasing struggle" inspired by the insights of Moses, Muhammad, Confucius, and Christ; each of these names is accompanied by a brief quotation on the screen, followed by references to a string of visionary leaders - Washington, Jefferson, Garibaldi, Lafayette, Kosciuszko, Bolivar, Lincoln - who have turned the wisdom of the sages into action. The narration invokes freedom and liberty many times, although the concepts are never defined.

In the slave world, by contrast, freedom has been killed in the name of progress by such treacherous tyrants as Mussolini, an "ambitious rabble rouser," and Hitler, an "even more forceful demagogue." Hirohito is a little different but equally bad; although he poses as a god and receives "fanatical worship," he is merely a front for a scheming gang that has erased "what little freedom [the Japanese people] had ever known." Using the kind of slangy language that GIs presumably enjoy, Huston's voiceover explains that the Axis countries are "hopped up" on the notion that their innate superiority makes domination of the globe their natural destiny. Only the Western world's grit, determination, and fighting spirit - another kind of superiority - can stop them from attaining their despotic goals.

Prelude to War doesn't hesitate to paint entire cultures with a broad stereotypical brush; the German people "have an inborn national love of regimentation and harsh discipline," for instance, and the populations of the Axis countries have thrown away not just their liberty but their souls, choosing to become "a mass, a human herd" bereft of dignity and individuality. Nazis use an assembly-line approach to creating the next generation of loyal subjects, the movie claims, showing babies in a crowded German nursery to prove the point. Hitler's hostility to Christianity and the Nazis' indoctrination of children get a lot of attention, while German anti-Semitism and the country's horrendous pre-war inflation get little or none. Prelude to War contains many simplistic and one-dimensional moments, but balance is beside the point in a film produced for the express purpose of uniting its viewers behind a patriotic cause.

"This isn't just a war," the film concludes. "This is a common man's life- and-death struggle against those who would put him back into slavery." At stake are "our homes, the jobs we want to go back to, the books we read, the very food we eat, the hopes we have for our kids, the kids themselves." Only one course of action makes sense. "It's us or them. The chips are down. Two worlds stand against each other. One must die. One must live."

Touching the sentiments of the "common man" was Capra's stock in trade as a top-grossing Hollywood director, and his talents are on full display in this 52-minute documentary. Its guiding principle is that the best way to persuade an audience is by spelling out plain, unambiguous arguments in the boldest possible terms. Prelude to War is far from subtle, but nuance is not its business.

Directors: Anatole Litvak, Frank Capra
Producer: The War Department, in cooperation with the Research Council, Academy of Motion Picture Arts and Sciences
Screenplay: Julius J. Epstein, Philip G. Epstein, Robert Heller, Eric Knight, Anthony Veiller
Cinematographer: Robert J. Flaherty
Film Editing: William Hornbeck
Music: Alfred Newman
With: Walter Huston
BW-52m.

by David Sterritt