The idea of ‘Fortress Norway’ was one of Hitler’s big mistakes. After the raid on Måløy and Lofoten he was convinced that the British were planning to invade Norway. In January 1942, at a ‘Führer Conference’, he declared that the fate of the war hung on Norway and that Norway must be prepared to meet this fate.

This was the start of an enormous defensive building boom in Norway. Up to 150,000 Norwegians worked for the Germans in building airfields, fortifications, harbours, and roads. In the next three years the number of German troops in Norway increased to a peak of 430,000. These troops were not raw recruits but seasoned soldiers with battleground experience.

Even after the Allied landing in Normandy the number of troops in Norway remained high because Hitler was stubborn and the Norwegian resistance often sabotaged troop movements.
The paradox here was that while the British wanted Norway to remain peaceful, Norwegians in the Resistance pleaded for more sabotage action.
A fine balance was maintained and because so many German troops were bottled up here, Norway did become one of the deciding factors in the war – but not in the way Hitler had predicted.