Japan would probably change little because its capital-ship program was already aimed primarily at the United States, while Germany still lacked the freedom to answer immediately. The United States might find the British ships less provocative than actual 16-inch Nelsons, though their existence could weaken later American support for returning to a 14-inch treaty limit. Italy and France face the most direct design pressure because their Mediterranean fleets would meet the British ships more immediately. Shared Anglo-French guns and shells sound logistically attractive, but French willingness to buy a British design appears politically implausible.
Notable Point · 53:09-54:22
How other navies might answer a British 15-inch/50 fleet
A standardized British heavy gun would affect rivals unevenly: Japan and Germany retain their main paths, while American treaty policy and Italian and French battleship choices face more pressure.