How short-war nuclear assumptions cut conventional fleets

Are navies returning to the assumption that a conventional war will become nuclear within a few days?

Not explicitly, but that old assumption saved money by eliminating the need for deep stocks, escorts, and carriers, and its effects still shape procurement.

Governments have not openly returned to the short-war assumption, but its budgetary attraction is obvious. If a conflict is expected to become nuclear within days, planners can avoid buying deep munitions stocks, convoy escorts, and carriers for a sustained Atlantic battle. This logic runs through British procurement and reaches back to the 1966 carrier decision. Cold War assumptions can therefore survive in fleet structure long after the strategic context has changed.