The Washington Naval Treaty and the later London treaties imposed different limits. Washington capped capital ships and carriers, but ships at or below the 10,000-ton cruiser limit were not subject to an aggregate number restriction. Lexington and Saratoga entered service in 1927, before the 1930 London treaty created cruiser categories and cumulative limits. Their eight-inch guns reflected gunnery culture and congressional reluctance to fund enough cruisers, rather than a treaty ban on building escorts.
Chapter · 11:12-14:20
Treaty limits did not require eight-inch guns
The treaty chronology challenges the claim that Lexington's eight-inch battery was forced by a shortage of allowed cruisers.