After the Winter War between Finland and Russia broke out in November 1939 the 6th Division was mobilised and Fleischer repeatedly took the initiative to encourage the Norwegian government to increase the country's military readiness in North Norway. Included amongst these initiatives were wide-ranging measures against the region's communists. Fleischer's distrust of the Soviet Union continued to show itself throughout the following Norwegian Campaign in 1940, when he kept substantial forces at the Soviet border in eastern Finnmark despite a desperate need of reinforcements at the front line at Narvik against Maj. Gen. Eduard Dietl's Gebirgsjäger forces.