Why 30, 19, and 17 were not equivalent cuts

The American proposal was that the United States decommission or not build thirty warships if Britain did the same for nineteen and Japan for seventeen. Britain's nineteen consisted of eleven ships to be decommissioned and eight planned ships that would not be built. The American and Japanese totals included programmes extending roughly six to eight years into the future, whereas the British plan covered a shorter period of about four years. Britain also began with Hood, Renown, Repulse, numerous 15-inch-gun ships, and surviving 13.5-inch-gun capital ships already available. A larger numerical American cancellation therefore did not automatically represent a larger sacrifice in usable strength. Starting fleets and planning horizons must be compared before the treaty totals can be treated as equivalent.