How long would the C- and D-class cruisers have remained in service without the Second World War?
Short answerProbably until about 1942-43, depending on the delivery rate of Dido-class cruisers and their successors.
NotesThe ageing C- and D-class cruisers could disappear by about 1942 or 1943 in a no-war timeline. The pace would depend on how quickly the Dido class and follow-on cruisers entered service. First Sea Lord Dudley Pound favored numerous small general-purpose cruisers, while Andrew Cunningham preferred larger ships. Cunningham's views on large cruisers and destroyers then evolved substantially under wartime experience before he became First Sea Lord.