Postal Censorship and the Alchemy of Victory at Sea during the First World War

Economic warfare shaped the First World War, but neither its execution nor its effect have been studied thoroughly. Economic warfare usually is seen just as a matter of warships; in fact, it stemmed from and was waged through a combination of diplomacy, intelligence, law, and seapower. The Royal Navy might have exercised blockade simply through strength, but Britannia did not wish to rule the waves by force alone. Britain cared about being, and seeming to be, lawful in action, which also eased the diplomacy of economic warfare. Intelligence, especially intercepted cables, wireless and, above all, the international post, unified seapower and sea law. Seapower enabled diplomacy, intelligence and law. They executed seapower. In particular, only overwhelming seapower could make every neutral at once tolerate British interception of their seamail, which was inconvenient and, neutrals thought, illegal. In turn, the postal censorship, Britain’s most feminised department of state, matched the most manly of arms as a tool of seapower.