Deception and intelligence failure: Anglo‐German preparations for U‐boat warfare in the 1930s

Abstract

This essay examines the key role played by intelligence and deception in the interactive process of British and German preparations in the 1930s for U‐boat warfare. It argues that the Royal Navy (RN) employed the general perception of ASDIC (sonar) as an ‘antidote’ to the submarine to mislead potential foes about the state of its anti‐submarine defences. This British campaign of deception had a discernible impact. Before the outbreak of World War II, the German Navy failed to discover the realities behind ASDIC's image, and this intelligence failure helped to shape U‐boat policy.