A lost warship can create an invasion scare, but the financial and social effects of losing thousands of merchant vessels produce a longer political memory. Naval value is measured through direct questions: can the fleet defend friendly commerce, keep its own maritime communications open, and close those available to the enemy? Sea lines of communication are not fixed roads, since ships alter their tracks for efficiency, weather, waves, and currents across a broad navigable surface. Concentrating or restricting that freedom creates vulnerabilities that commerce warfare can exploit.
Notable Point · 46:00-48:02
Merchant losses make trade protection a test of naval value
The political memory of lost merchantmen turns protection of maritime movement into a public measure of whether a navy is fulfilling its purpose.