Though these opinions were overly optimistic, it is true that the German army was not in an ideal condition. Field Marshal Gerd von Rundstedt, along with other senior officers, opposed Hitler's plan. They argued that Germany no longer possessed the resources necessary for the success of such an operation. Hitler refused his officers' advice (Macdonald 158).
On the morning of December 16th, American forces in the region were surprised by three German armies rolling out of the Ardennes. The Sixth SS Panzer Army, commanded by General Josef "Sepp" Dietrich, along with General Hasso von Manteuffel's Fifth Panzer Army, made up the main striking force (Sears 25). General Erich Brandenberger's smaller Seventh Army played a supporting role (26). The plan was for Manteuffel and Dietrich's armies to drive through the American forces, cross the Meuse River, and then split up to capture Brussels and Antwerp. The Fifth Panzer Army defeated the U.S. 28th & 106th divisions, breaking through the line at Schnee Eifel (Macdonald 162). Farther north, the Germans captured the towns of Honsfeld and Losheim, opening another gap in the U.S. line. Through this hole poured the Sixth SS Panzer Army. The Germans advanced five miles on the first day (Sears 35).
Despite these early successes, the German armies soon met with serious resistance. The cities of St. Vith and Bastogne, with their networks of roads, were both critical to the German plan (Cole 162). On December 17th, Sepp Deitrich's army reached St. Vith and began a series of unsuccessful attempts to take the city (275). Though his schedule called for the capture of St. Vith on the second day of the battle, Deitrich did not take the city until the 21st, when he attacked the small American force with 100,000 men and 200 tanks (Sears 65). On the 20th of December, the Fifth Panzer Army found the city of Bastogne defended by a single U.S. division, the 101st Airborne.