The blockade of Germany

In the absence of a land offensive during the Phoney War, the Allies banked on an indirect weapon: the economic blockade of Germany, through command of the seas. The idea, inherited from 1914–1918, was to slowly strangle the German war economy by cutting off its access to raw materials (oil, ores, rubber) and to imports.

The Allied command had to define its economic strategy. To bank on the naval blockade and patience, wagering that economic asphyxiation would eventually force Germany's hand. To strike directly at the sources of supply (Swedish iron via Narvik, Romanian or Caucasian oil), at the risk of extending the conflict to neutral countries. Or to combine blockade and peripheral operations.

The wager of the blockade rested on duration and on the idea that time was on the Allies' side. But it overlooked the fact that Germany, bound to the USSR by the 1939 pact, could obtain supplies in the East, and that a swift victory in the West would render the blockade pointless. Economic warfare, a strategy of patience, presupposed that one had the time.