Operation Dragoon was considered a success by the Allied forces. It enabled them to liberate most of southern France in only four weeks, while inflicting heavy casualties on the German forces. However, the Allies failed to cut off the most valuable units of the retreating Army Group G, which retreated over a distance of in good order, into the Vosges Mountains on the German border, with the capability of continuing the fight. The main reason for the failure to capture or destroy Army GroupG was the Allied shortage of fuel, which began soon after the landing. The Allies had not anticipated the speed of their own advance, so could not adequately provide supplies and logistics to the leading Allied units.