This book focuses on the Royal Navy's response to the rise of the German navy under Hitler within the broad context of the ongoing debate about Britain's policy of appeasement. It combines a narrative of diplomatic events and Whitehall policy-making with the thematic analysis of naval intelligence and war planning. Drawing on the wide range of sources, the author argues that the Admiralty's enthusiasm for naval armaments diplomacy with Nazi Germany was far more rational and more complex than previous studies would suggest.