With the release of shipping and landing craft from OVERLORD, it became possible to stage the long-planned invasion of southern France, the so-called Operation DRAGOON. While the battle of Argentan-Falaise pocket was still raging, on 15 August 1944, Lt. Gen. Alexander Patch's U.S. Seventh Army invaded the Mediterranean shores of France southwest of Cannes. The attacking force comprised contingents of three U.S. infantry divisions plus an airborne task force and French commandos, and it was assisted by Free French forces after the landing had been made. Basic objectives were to prevent the reinforcement of German forces in Normandy with troops from southern France and to provide the Allies a supplementary line of communications through Mediterranean ports. Resistance was comparatively light. Advances north were rapid, and by 11 September patrols from the southern and northern Allied forces met near Dijon. On 15 September the U.S. 6th Army Group became operational under command of Lt. Gen. Jacob L. Devers and, with the U.S. Seventh Army and the First French Army, passed from control of Allied Force Headquarters to the control of Supreme Headquarters, Allied Expeditionary Force (SHAEF). Thereafter forces from the south continued toward Germany in contact with the U.S. Third Army.

On the western front logistical problems had become acute by the autumn of 1944. Although the U.S. First Army under Lt. Gen. Courtney H. Hodges had penetrated the so-called West Wall in several places, lack of supplies prevented exploitation of the breaks. Bad weather, terrain that restricted maneuver, and the dense fortifications along the German border combined to create obstacles of major proportions.

To two of General Eisenhower's subordinate commanders, Montgomery and Patton, Eisenhower's decision to advance into Germany on a broad front seemed like a mistake in light of the logistical limitations. Each wanted all resources put behind his part of the front to support one major drive into Germany, in the hope that German disorganization could be exploited to produce capitulation. The debate continued through the late summer and much of the fall of 1944, but General Eisenhower, backed by the advice of his logisticians, stuck to his original plan of advancing with all armies abreast, though with greater emphasis in the north.