The United States had reason to expect large cruisers from potential rivals. German Deutschland-class ships, Japanese B65 planning, and British work on a 9.2-inch cruiser all supported that concern. American assessments treated the turret arrangement of Belfast and Edinburgh as preparation for eight 9.2-inch guns in four twin mountings, although the British ships were being developed with 6-inch guns. In Pacific operations, a large cruiser would need range and speed to support scouts far from the fleet. It had to discourage enemy cruisers long enough for those scouts to bring their information back. Lexington and Saratoga's 8-inch guns added topweight without removing the disadvantages of taking a large, fuel-laden carrier into an artillery fight. Even an armed carrier therefore needed a surface escort to help it avoid that situation.
Chapter · 3:57-6:39
Why a large cruiser looked useful
German, Japanese, and British large-cruiser possibilities help explain why the United States could see a fast, heavy scouting ship as a credible requirement.