The treaty's equality ratio looks equitable only until strategic coverage is considered. Japan could focus its allocation in one principal ocean, while the United States had two-ocean obligations and Britain had to divide similar totals across three major oceanic theaters. Dividing the same headline tonnage among those commitments yields very different concentrations of usable force. Britain and the United States accepted equality partly to keep Japan from upgrading Pacific fortifications, though it might improve them secretly and later left the treaty system. Britain also repeatedly proposed a total submarine ban without gaining anything in return when those proposals failed.
Notable Point · 20:28-22:19
One-, two-, and three-ocean navies under one limit
Equal submarine tonnage is divided among Japan's one-ocean focus, America's two-ocean obligations, and Britain's three-ocean fleet, undermining simple treaty equality.