Waarschijnlijk is dit E for Effort , een romanette uit 1947 van TL Sherred.
Taking place at some time in the near future (relative to when it was written), the story is briefly framed as a manuscript delivered to a civilian by the military under circumstances of great tension.
The manuscript is a long letter to "Joe", apparently a bartender, by Ed Lefko. He describes seeing a silent but color movie aimed at Mexican-Americans in a run-down theater in Detroit. The movie recounts Cortés's conquest of Mexico with remarkably realistic sets and acting and a huge cast. The projectionist, a World War II veteran named Miguel "Mike" Laviada, tells Ed that he made the movie using a time viewer he invented, which he demonstrates. However, Mike has not been able to raise the capital needed to shoot the picture on high-quality film, add sound and other improvements, and get it distributed and advertised. He and Ed become partners, and at Ed's suggestion, they raise money by using the machine to blackmail wealthy people.
They spend a year making most of a new film out of time-viewed footage of Alexander the Great. They take it to Hollywood, where the high quality of the film easily convinces a producer and his associates to finish it, including using actors for scenes that appear in Alexander's biographies but did not really happen, and market it. The film is a great success with critics and viewers.
Ed and Mike admit the machine's existence to their associates and persuade them to join in their plan to expose the corruption of many famous people involved in the wars. The film causes riots in many countries and greatly increases international hostility.