Completed British 18-inch capital ships before Washington could have pushed the United States and Japan toward similar weapons. In this counterfactual, an 18-inch ceiling might require a roughly 45,000-ton individual limit. Germany could remain constrained by its route from existing 11-inch guns toward a new 15-inch weapon, while Italy might have time to develop larger guns. France's smaller-calibre ships would face a more difficult competitive position. These different national responses mean that historical American and Japanese Second World War designs cannot simply be carried unchanged into the scenario.
Notable Point · 2:52:34-2:55:55
How British 18-inch ships could have changed treaty naval competition
An 18-inch Washington Treaty ceiling could require larger hulls and produce different design responses from the major naval powers.