How would a January 1939 Far East war change British, French, and American naval construction plans?
Short answerBritain would probably accelerate fast battleships and fleet carriers. Montana-class and French carrier choices would depend on the war's duration and the experience gained from combat.
NotesThe answer starts from Britain's prewar expectation that a major conflict could arise in Europe or the Far East by 1942-43. An actual war in 1939 would keep fast-capital-ship orders moving. Lion-class battleships and fleet carriers would probably be accelerated for operations against Japan. U.S. Montana-class construction and French carrier development remain contingent outcomes shaped by the length of the war and what combat reveals.