Had Japan developed its mass night-torpedo attack doctrine by 1939, and could the Allies counter it?
Short answerYes, the doctrine existed, but British and American destroyer screens, British night-fighting skill, and prior knowledge of the concept would complicate its execution.
NotesThe doctrine existed by 1939, but the British understood it and were capable night-fighters themselves. Tribal-class destroyers and the many other British destroyers accompanying the fleet would contest the approach lanes rather than leave the battle line exposed. American destroyers would add still more screening strength in the coalition scenario. Darkness limits detection range for both sides, so Japanese torpedo doctrine remains dangerous without becoming an automatic solution to Allied numerical superiority.