How a 13.5-inch Dreadnought changes the naval race

What if HMS Dreadnought began the race with 13.5-inch guns?

Germany and the United States would accelerate larger-gun programmes, but the added cost might also price Germany out of a sustainable dreadnought competition much earlier.

A Dreadnought armed with 13.5-inch guns could push Germany towards 12-inch weapons sooner, although Nassau would probably retain its 11-inch guns. The United States would face pressure to accelerate its 14-inch programme, but developing the gun and preparing machinery to manufacture its barrels would still take time. In this counterfactual, Britain could progress through 15-inch and 16.5-inch guns to 18 inches, while the American sequence could run through 14, 16 and 18 inches. That convergence suggests an eventual treaty limit of 18 inches. Larger weapons would also raise battleship costs from the beginning, potentially weakening Tirpitz's competition with the German Army enough to disrupt the naval race.