Due to the length of the front created by the German summer offensive, aimed at taking the Caucasus oil fields and the city of Stalingrad, German and other Axis forces were forced to guard sectors beyond the length they were meant to occupy. The situation was exacerbated by the German decision to relocate several mechanized divisions from the Soviet Union to Western Europe. Furthermore, units in the area were depleted after months of fighting, especially those which took part in the fighting in Stalingrad. The Germans could only count on the XXXXVIII Panzer Corps, which had the strength of a single panzer division, and the 29th Panzergrenadier Division as reserves to bolster their Romanian allies on the German Sixth Army's flanks. In comparison, the Red Army deployed over one million personnel for the purpose of beginning the offensive in and around Stalingrad. Soviet troop movements were not without problems, due to the difficulties of concealing their build-up, and to Soviet units commonly arriving late due to logistical issues. Operation Uranus was first postponed from 8 to 17 November, then to 19 November.