Why was the Royal Navy so concerned about a German breakout into the Atlantic?
Short answerA concentrated German surface force could range widely against vulnerable convoys before later-war surveillance and escort systems existed.
NotesThe problem was one of geography and concentration: a German force of capital ships, cruisers, destroyers, and supply vessels could appear anywhere in the North Atlantic. Before later-war radar, air patrols, escort carriers, and intelligence systems matured, stopping such a sortie required a major British task force. The fear was therefore about protecting many dispersed convoys against a mobile concentrated enemy.