The German Invasion of Norway, 1940: The Operational Intelligence Dimension

While many analyses of the 9 April 1940 invasion of Norway have looked at the successful interplay of German air, sea and land components, the part performed by intelligence has largely received only cursory attention. This article seeks to redress this, and investigates the pivotal role intelligence played in the planning, preparation, and carrying out of Weserübung. The study examines the dearth of relevant information in the early planning stage; the subsequent accumulation of military assessments of Norway's defensive capabilities; the process of denying London and Oslo intelligence regarding Berlin's intentions; the significance of Danish and Norwegian airfields to the operation; and the importance of maritime reconnaissance and wireless intercepts in monitoring the disposition of the Royal Navy. Although primarily concerned with German intelligence gathering and utilisation, British efforts, including the potential impact of Ultra, are also considered.