The 10:10:7 allocation gives Japan a plausible local carrier advantage without global superiority. Seven Japanese carriers might concentrate in the western Pacific against perhaps five American carriers in the eastern Pacific and three British carriers in the Indian Ocean. Combining the British and American detachments produces an eight-to-seven balance before further reinforcement. Theater distribution and coalition concentration therefore matter as much as the treaty's headline fleet ratio.
Notable Point · 42:02-42:57
Regional carrier ratios depend on fleet concentration
Japan could concentrate seven carriers in the western Pacific, but combined or reinforced Anglo-American forces could erase that local numerical advantage.