In the 1930s the United States drew up War Plan Red, a real contingency scheme for fighting the British Empire, complete with invasion routes into Canada and naval strategies for the Atlantic. Military historians and defense professionals walk through the declassified plan section by section, explaining how American planners expected a war with Britain to start, which fronts would open first, and what resources each side could actually bring to bear. Using period maps, archival documents, and expert commentary, the film reconstructs a hypothetical conflict move by move, weighing troop numbers, naval strength, and industrial capacity on both sides. The analysts are candid about the plan's limitations and the political absurdity of the scenario even as they take its logistics seriously, treating it as a genuine artifact of interwar military planning rather than a curiosity. The result is a plausible campaign history for a war that never happened, built entirely from the assumptions its own authors put on paper.