Lieutenant General Omar Bradley, commanding the 12th Army Group, in whose sector the offensive had begun, urgently sent two Div. tanks to stem the enemy invasion and, at the same time, General Eisenhower, commander of the Allied forces in Western Europe, released from its reserves the XVIII Airborne Corps, which was at rest in the Reims region after its participation in the Operation "Market-Garden".
Both Divs. of this corps left immediately for the Ardennes by truck:the 82nd Div. airborne, of Major General Matthew Ridgway, towards the northern flank of the salient created by the Germans and the 101st Div. airborne, temporarily commanded by Brigadier General Anthony McAuliffe, towards Bastogne, the key to the southern flank. Other Allied units were urgently assigned to new missions, but their movements were to take some time; so the defense of the salient initially relied on these reinforcements alone.
The 101st Div. airborne arrived in Bastogne on December 19 and immediately organized the defense of the city. Major General Troy Middleton, commanding the US VIII Corps, who was in the area, visited McAuliffe on the 19th and succinctly ordered him to "hold Bastogne"