A submarine-heavy German building programme would let Britain focus on a more clearly defined threat. Greater production of Flowers and other anti-submarine assets would be the expected response. Surface and air threats instead require different defensive investments. A balanced German fleet could therefore impose demands absent from a submarine-only force. Germany's surface fleet would have been more capable if war had come later, after more of its programme was complete. In this assessment, Italy was the stronger Axis naval power before Japan joined.
Notable Point · 2:37:36-2:39:53
Why a submarine-only fleet could simplify British defence
More German submarines before the war would also give Britain a clearer production priority.