Opening a "Second Front" was a top priority for the Allies, and especially for the Soviets to relieve their burden on the Eastern Front. While Italy had been knocked out of the war in the Italian campaign in September 1943, the easily defensible terrain of the narrow peninsula required only a relatively limited number of German troops to protect and occupy their new puppet state in northern Italy. However, as the Dieppe raid had shown, assaulting the Atlantic Wall was not an endeavour to be taken lightly. It required extensive preparations such as the construction of artificial ports (Operation Mulberry) and an underwater pipeline across the English Channel (Operation Pluto), intensive bombardment of railways and German logistics in France (the Transportation Plan), and the wide-ranging military deception such as creating entire dummy armies like FUSAG (Operation Bodyguard) to make the Germans believe the invasion would take place where the Channel was at its narrowest.