In December 1941, Japanese Admiral Isoroku Yamamoto reportedly warned that Japan could only sustain war with the United States for about six months before American industrial power overwhelmed it. This episode of the WW2 in Numbers series tests that prediction against the historical record, tracking how the shock of Pearl Harbor converted American factories, shipyards, and civilian labor into a wartime production machine at a scale Japan's planners had not accounted for. Archival footage of assembly lines, launched ships, and factory workers is paired with expository narration that lays out production figures for aircraft, vessels, and materiel, and traces how that output fed directly into the Pacific campaign. The Battle of Midway anchors the back half of the film as the moment the balance of power visibly shifts, presented less as a story of tactics than as the arrival of Yamamoto's warning in real time. The film's case is numerical rather than sentimental: Japan lost the war in the shipyards and factories months before it lost it at sea.