Building carrier task forces without fast battleships

Early American carriers had no fast battleship escort because South Dakota's 27.5 knots was marginal for the role and the Iowa class was not yet available. An Iowa would likely have accompanied the Doolittle force if one had existed, because it could match the carriers and deter a Kongo-class interception. British doctrine likewise paired carriers with fast capital ships, but the losses of Hood and Repulse left only Renown for that work. Carrier speed mattered both for flight operations and for strategic mobility, which excluded many otherwise powerful battleships. American heavy cruisers supplied speed and range but inherited limited protection from their scout-cruiser origins. Destroyers faced their own difficulty sustaining high speed, and the fleet had too few of the light cruisers best suited to escort work.