Treaty limits made ship numbers the central problem

The Washington and London treaty systems limited the tonnage and numbers available to every navy, but the effect was especially awkward for a service with worldwide commitments. Britain sought more usable hulls by converting some heavy-cruiser allowance into light cruisers and by exploiting the permitted destroyer-leader category. That choice treated physical presence as the scarce resource: a ship had to be available on station, not merely represented by an aggregate tonnage allowance. Other navies emphasised enlarged torpedo destroyers, while the Royal Navy developed the gun-heavy Tribals for a broader set of tasks.