how were allied troops able to defeat the german advance at the battle of the bulge
Battle of the Bulge The Germans achieved total surprise on the morning of 16 December 1944, due to a combination of Allied overconfidence, preoccupation with Allied offensive plans, and poor aerial reconnaissance. The Germans attacked a weakly defended section of the Allied line, taking advantage of heavily overcast weather conditions that grounded the Allies' overwhelmingly superior air forces. Fierce 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 that they counted on for success. Columns of armor and infantry that were supposed to advance along parallel routes found themselves on the same roads. This, and terrain that favored the defenders, threw the German advance behind schedule and allowed the Allies to reinforce the thinly placed troops. Improved weather conditions permitted air attacks on German forces and supply lines, which sealed the failure of the offensive. In the wake of the defeat, many experienced German units were left severely depleted of men and equipment, as survivors retreated to the defenses of the Siegfried Line.
Operation Barbarossa Operationally, German forces achieved major victories and occupied some of the most important economic areas of the Soviet Union, mainly in the Ukrainian Soviet Socialist Republic, and inflicted, as well as sustained, heavy casualties. Despite these Axis successes, the German offensive stalled in the Battle of Moscow and the subsequent Soviet winter counteroffensive pushed German troops back. The Red Army absorbed the Wehrmacht's strongest blows and forced the unprepared Germans into a war of attrition. The Wehrmacht would never again mount a simultaneous offensive along the entire strategic Soviet–Axis front. The failure of the operation drove Hitler to demand further operations of increasingly limited scope inside the Soviet Union, such as Case Blue in 1942 and Operation Citadel in 1943 – all of which eventually failed.