on 27 august, in anticipation of war with nazi germany, the french navy planned to reorganize the mediterranean squadron into the fhm of three squadrons. when france declared war on 3 september, the reorganization was ordered and the 3rd light squadron, which included the 5th and 9th scout divisions with all of the "vauquelin"-class ships, was assigned to the 3rd squadron which was transferred to oran, french algeria, on 3 september. the 9th scout division with "cassard", "kersaint" and "maillé brézé" was assigned to escort duties until april 1940, although the former ship was detached (12 november–21 january 1940) to force x in the atlantic which was tasked to search for german commerce raiders and blockade runners. afterwards "cassard" rejoined her scout division which had returned to toulon during her deployment. she was transferred to the 5th scout division in early june. anticipating a declaration of war by the italians, the mediterranean fleet planned to bombard installations on the italian coast. after they declared war on 10 june, "cassard" and the rest of the 5th scout division were among the ships ordered to attack targets in vado ligure on 14 june. the destroyer was tasked to bombard factories in the town. two italian mas boats on patrol attempted to attack the french ships, but only one was able to launch a torpedo before they were driven off with light damage by the french defensive fire. damage assessments afterward revealed that little damage had been inflicted despite expending over 1,600 rounds of all calibers.