What if all Japanese battleships in 1918 became copies of the Ise and Kii designs?
Short answerA Kii-style Japanese battle line would be fast, heavily armed, and difficult for any navy to fight, forcing major British and American reactions.
NotesThe counterfactual gives Japan a battle line capable of 29.75 knots, with ten 16-inch guns per ship and heavy secondary armament. Kii's quoted displacement is 42,600 tons normal and 48,500 tons fully loaded. Such a fleet could choose when and where to fight and disengage from slower opponents. American standard battleships are contrasted at about 21 knots with mostly 14-inch guns in 1918. Britain would also face pressure to commission fast capital ships capable of answering it. The panel expects either a very different Washington Naval Treaty or no comparable agreement. The later Number 13 design illustrates the same direction of development with eight 18-inch guns and a proposed speed of 30 knots.