Army Group B :. Estimate: , [ 13 ] [ f ] casualties. The Netherlands. The offensive was intended to stop Allied use of the Belgian port of Antwerp and to split the Allied lines, allowing the Germans to encircle and destroy each of the four Allied armies and force the western Allies to negotiate a peace treaty in the Axis powers ' favor. The Germans achieved a total surprise attack on the morning of 16 December , due to a combination of Allied overconfidence, preoccupation with Allied offensive plans elsewhere and poor aerial reconnaissance due to bad weather.
American forces were using this region primarily as a rest area for the U. First Army, and the lines were thinly held by fatigued troops and inexperienced replacement units.
The Germans also took advantage of heavily overcast weather conditions that grounded the Allies' superior air forces for an extended period. American resistance on the northern shoulder of the offensive, around Elsenborn Ridge , and in the south, around Bastogne , blocked German access to key roads to the northwest and west which they had counted on for success.
This congestion and terrain that favored the defenders, threw the German advance behind schedule and allowed the Allies to reinforce the thinly placed troops. On 26 December the lead element of Patton's U. Third Army reached Bastogne from the south ending the siege. Although the offensive was effectively broken by 27 December, when the trapped units of 2nd Panzer Division made two break-out attempts with only partial success, the battle continued for another month before the front line was effectively restored to its position prior to the attack.
The Germans committed over , men, just over 1, tanks and armored fighting vehicles , 2, artillery pieces, and over 1, combat aircraft. The battle severely depleted Germany's armored forces, which remained largely unreplaced throughout the remainder of the war. German Luftwaffe personnel, and later also Luftwaffe aircraft in the concluding stages of the engagement also sustained heavy losses. In the wake of the defeat, many experienced German units were effectively out of men and equipment, and the survivors retreated to the Siegfried Line.
