Following Hitler's December 1941 declaration of war upon the United States German Admiral Karl Doenitz sought to take advantage of the weakly guarded sea-lanes near the American coast and pick off the highly vulnerable, solitary, merchant ships plying these waters. Hitler approved Doenitz's plan, code named Operation Paukenschlag, or drumbeat/roll the drums. Doenitz' U-boats would carry Hitler's war to America and if successful deliver the first blows designed to cripple American shipping and industry.
Scandinavia took on ample significance to both Germany and Britain late in the winter of 1939-1940. The subsequent events in Scandinavian waters during the spring of 1940 would prove even more strategically significant following France's capitulation in June of 1940. The following will explain why.
Following the outbreak of the Second World War, a politically weakened Neville Chamberlain had brought one of his leading dissenters, Winston Churchill, into his cabinet as First Lord of the Admiralty; in an attempt to silence Churchill's politically damaging critiques of Chamberlain's leadership.