The American requirement for a fifteen-ship battle fleet is tied to keeping credible forces on two coasts. Britain faces a different distribution problem across home waters, the Mediterranean, and the Far East, while Japan's single-ocean focus is also its economic lifeline. France and Italy share a nominal ratio but have unequal strategic burdens, making the Mediterranean balance central to the treaty bargain. Britain benefits when Japan absorbs American attention and France and Italy balance one another, leaving the Royal Navy greater freedom elsewhere. The familiar 5:5:3:1.75:1.75 formula therefore reflects geography, alliance calculations, and the minimum force each government believed it could accept.
Chapter · 10:01-18:57
Treaty ratios through national strategic needs
The familiar capital-ship ratios look different when viewed through American two-ocean planning, British imperial commitments, Japanese security, and the Franco-Italian Mediterranean balance.