German merchant sailors become strategic manpower

The Battle of the River Plate and the loss of Admiral Graf Spee exposed Germany's need for experienced seafarers while Royal Navy dominance made an ocean return dangerous. Another German surface raider was recalled rather than risked under the same conditions. Italy remained outside the war and France still fought beside Britain during the Phoney War, so Royal Navy infrastructure and worldwide presence gave it an overwhelming advantage across the ocean routes. Germany had lost ships and now faced a growing pool of skilled personnel stranded overseas. Apparently civilian seafarers therefore became strategically important targets for British maritime interdiction.