What caused of the Battle of the Bulge?

The Germans had been fighting on the defense since the Allies landed on Normandy. The Germans wanted to launch an offensive attack that would demoralize the Americans and hopefully convince them to negotiate for peace. At the same time, the attack might push far enough into Belgium to capture a fuel supply dump that the Germans desperately needed. The Germans launched the attack at the weakest part of the Allied line. The US 106th Infantry Division was new to the battlefield and they were placed in the line right where the German thrust was aimed. The 106 Division had come almost directly from the Unite States, without significant retraining in England, and was just beginning to sort itself out in the quiet Ardennes. As a sideline, the Germans launched a small offensive in Italy against the 92nd Infantry Division, in the Serchio Valley on 26 December 1944. This attack was named Operation WINTERGEWITTER and involved only a division-size task force. It caused the break-up of the 92nd Division and complete routing of 1 regiment, resulting in a total of 529 killed, wounded and missing. The Americans were able to recover from the German attack and eventually pushed the "bulge" back to where the front line was before it started. The Germans did not gain anything from the attack except it made the Allies more cautious about the Germans.