remembered that American troops were in constant movement to Europe and the higher staffs tended to look upon the next few troopships as containing a reserve which could and would be used by the Supreme Commander to influence the direction of the battle. Four U.S. infantry divisions and one armored division were scheduled to arrive on the Continent in December, with an equal number slated for January. Of the December contingent two infantry divisions (the 87th and 104th) were already in the line when the Germans struck. There remained en route the 11th Armored Division and the 66th and 7th Infantry Divisions, the 75th having already crossed the Channel on its way to the front. Two additional U.S. divisions were training in the United Kingdom and waiting for equipment, but neither was expected to cross the Channel during December: the 17th Airborne was scheduled for France in January, and the 8th Armored Division, still missing many of its authorized vehicles, was not as yet on a movements list. 
The only combatwise divisions ready to the hand of the Supreme Commander were the 82d and 101st Airborne Divisions, which had been brought back to France after the long, tough battle in the Netherlands and were not expected to regain full operational status until mid-January. By the 17th, however, it was clear that the First Army had to be heavily reinforced, and promptly. General Eisenhower reluctantly gave the airborne troops to Bradley.
From this point on the immediate reinforcements needed to meet and halt the German counteroffensive would have to come from the armies in the field. (Simpson had already thrown the 30th Infantry into the pot, in addition to the 7th Armored.) Late in the evening of the 17th Bradley telephoned Patton, who was starting to move his troops into assembly areas for the Third Army attack on the Saar, and told the latter that two more divisions might have to go north. By midnight of 17 December approximately 60,000 men and 11,000 vehicles were on the move to reinforce Hodges' First Army. In the following eight days three times this number of men and vehicles would be diverted from other areas to meet the Germans in the Ardennes.
One piece of military thinking dominated in all the higher U.S. military headquarters and is clearly traceable in the initial decisions made by Eisenhower, Bradley, and the army and corps commanders. The Army service schools during the period between the two World Wars had taught as doctrine- a doctrine derived from the great offensives of 1917 and 1918 on the Western Front-that the salient or bulge produced by a large-scale offensive can be contained and finally erased only if the shoulders are firmly held. The initial movements of the American reinforcements were in response to this doctrine.
The 30th Division Meets Peiper
The 30th Division (Maj. Gen. Leland S. Hobbs) was resting in the neighborhood of Aachen, Germany, after hard fighting in the Roer River sector, when a call from the XIX Corps informed its commander of the German attack along
 Hq SHAEF files: O and E SHAEF G-3, 370.5-4, vol. 1, Flow of Divisions.