Why carrier defence can begin far from home

American and British carrier doctrine remains defensive even though it operates at greater distance. Those navies use forward presence to keep hostile forces away from their homelands and vital routes, so apparently offensive deployments form part of a defensive strategy. Britain has an added structural reason: its island economy depends heavily on sea lines of communication and the global movement of goods and information. Soviet geography, land-war priorities, and naval funding instead favoured a closer bastion system. The difference lies in the means and the position of the defensive perimeter.