Five Came Back by Mark Harris (a columnist for Entertainment Weekly) says that film-directors John Ford, John Huston, Frank Capra, William Wyler and George Stevens faked scenes for propaganda-films that they made for the government of the United States during the Second World War.
Mark Harris on how John Huston faked The Battle of San Pietro:
"San Pietro was seen as a new pinnacle of realism. In some ways it was, insofar as John Huston's faked war-footage looked more like what we now think of as war-footage than anything that Americans had seen. He knew that you needed to have a shaky camera. He knew what a kind of vérité-style for war-footage should look like. But the fact is, it was all faked. He and his crew got to the battle after it was over. They had gone to Italy with the assigned mission to find a town that the Allies were about to liberate, and to film the victory, the liberation of the town, and the joyous return of the villagers. And when they got to San Pietro what they found instead was an abandoned town that had been shelled to bits, the Germans already in retreat, corpses of American soldiers all over the place, and mines and boobytraps everywhere they looked. So, the movie that became San Pietro was a restaged version of that battle that was shot over the next six weeks." [Mark Harris, NPR 22 February 2014]
Harris suggests that a realistic representation of what was happening might have damaged public support for the war:
“When you take away the whole question of fakery, it makes the combat look rough and frightening and punishing and makes the advance of a line of soldiers look slow and hesitant in ways that set it apart from Hollywood war movies and even from a lot of other documentaries.” [Express, 9 March 2014]
There are aspects of film-fakery during the Second World War that Harris likely does not discuss to any great extent in his book.
In addition to simulating battles, the directors would simulate atrocity-footage. Frank Capra used footage of Chinese Nationalist troops executing Chinese Communists to portray Japanese troops wantonly killing Chinese civilians. He accomplished this by cropping the frames and adding dramatized segments that induced viewers to interpret what they were seeing as a Japanese atrocity rather than what it was. (Details here.)
Capra was also not above misrepresenting clips from German newsreels, showing the suffering in eastern Poland under Soviet rule, as scenes of suffering under German rule.
At the end of the war, professional film-directors were also employed to make conditions in the concentration-camps look as bad as possible, and to blame the Germans for the deaths from typhus. George Stevens made a film that claimed gassings at Dachau, which was shown during the International Military Tribunal at Nuremberg. Alfred Hitchcock (not a Jew) made a similar film narrated by actor Leslie Howard, but it was never finished (and never shown until PBS Frontline got hold of it in the 1980s, a few years after Hitchcock's death). Billy Wilder, a Jew who had left Germany a few years earlier to become a famous director in Hollywood, was similarly engaged.