What might a 1918 start to the First World War have meant for British 12-inch dreadnoughts?
Short answerMost would probably have been replaced, transferred, or relegated because the Royal Navy was already moving toward much heavier-gun ships.
NotesThe counterfactual starts from the pace at which the Royal Navy was already replacing older 12-inch battleships with 15-inch ships. An 18-inch Agincourt-like design would make retaining those earlier dreadnoughts even harder to justify. It is doubtful that a 12-inch dreadnought would remain in front-line Royal Navy service by 1918. Survivors would more likely have moved to Dominion service or reserve while newer heavy-gun ships formed the active battle line.