Italian construction affects Britain because it must plan against the German, Italian, and Japanese fleets at once. French strength may balance Italy, but the Royal Navy still needs enough Mediterranean presence to turn parity into superiority. Britain cannot abandon that theatre while fighting Japan, since the Mediterranean and Suez route shortens the journey to the Far East and serves as an imperial supply line. British construction provokes Japanese responses, which influence American choices in turn. Britain's fleet requirement therefore spans connected theatres rather than matching any one opponent ship for ship.
Notable Point · 43:43-45:09
Britain's three-power problem and the Suez lifeline
Britain must plan against Germany, Italy, and Japan as one connected problem because the Mediterranean route sustains reinforcement of the Far East.