under the command of Army Group Don were retained by their original commands. Other units in Army Group Don were in no shape to conduct offensive operations, due to losses sustained in the past month of combat, while many new formations which had been promised did not arrive on time. On the other hand, the 11th Panzer Division was one of the most complete German armored divisions on the Eastern Front since it had just been transferred out of the German Army's reserve. The 6th Panzer Division was also complete because it had been transferred to Manstein's control from Western Europe. However, the usefulness of the 11th Panzer Division was compromised when the Soviets launched their offensive against forces in the lower Chir River area, as this tied Army Detachment Hollidt down on the defensive. Because of this, and because Manstein believed that a thrust originating from the position of Army Detachment Hollidt would be too obvious, the German field marshal decided to use the 4th Panzer Army and the LVII Panzer Corps as the main components of the relief operation. However, despite attempts by the Germans to build strength for the offensive, their position along the lower Chir River became tenuous; the Soviet breakthrough was only blunted by the arrival of the 11th Panzer Division, which was able to destroy the bulk of two Soviet tank brigades. Consequently, the XLVIII Panzer Corps became embroiled in the defensive battles for the Chir River, as the Soviets pushed in an attempt to overrun the airfield at Tatsinskaya (being used to resupply German forces in Stalingrad by air). Although the LVII Panzer Corps was reluctantly released to Army Group Don, by Army Group A, the 17th Panzer Division was ordered back to its original area of concentration, and did not prepare to go back to Army Group Don until 10 days after it had been asked for. In light of the troubles in building up sufficient forces, and seeing that the Soviets were concentrating more mechanization on the Chir River, Manstein decided to launch Operation Winter Storm using the 4th Panzer Army. Manstein hoped that the 6th Army would launch an offensive of its own, from the opposite side, upon the receipt of the code signal Thunderclap. Manstein was gambling on Hitler accepting that the only plausible method to avoid the demise of the 6th Army was allowing it to break out,