Hoepner was confident that clearing the pocket and the advance on Moscow, could be undertaken at the same time. He viewed Kluge's actions as interference, which led to friction and "clashes" with his superior, as he wrote in a letter home on 6 October. Hoepner did not seem to appreciate that his units were very short on fuel; the 11th Panzer Division reported having no fuel at all. Only the 20th Panzer Division was advancing towards Moscow amid deteriorating road conditions. On 17 November, the 4th Panzer Group again attacked towards Moscow alongside the V Army Corps of the 4th Army, as part of the continuation of Operation Typhoon by Army Group Centre. The panzer group and the army corps represented Kluge's best forces, most ready for a continued offensive. In two weeks' fighting, the German forces advanced ( per day). A lack of tanks, insufficient motor transport, and a precarious supply situation, along with tenacious Red Army resistance, and the air superiority achieved by Soviet fighters hampered the attack. Facing pressure from German High Command, Kluge finally committed his weaker south flank to the attack on 1 December. In the aftermath of the battle, Hoepner and Guderian blamed Kluge's slow commitment of the 4th Army's south flank to the attack for the German failure to reach Moscow. Historian David Stahel wrote that this assessment grossly overestimated the capabilities of Kluge's remaining forces. It also failed to appreciate the reality that Moscow was a metropolis, and German forces lacked the numbers to encircle it. With the outer defensive belt completed by 25 November, Moscow was a fortified position which the Wehrmacht lacked the strength to take in a frontal assault. Further attacks were called off on 5 December; the Red Army launched its winter counter-offensive on the same day. Army Group Centre After Fedor von Bock was relieved of his command of Army Group Center on 18 December, Kluge was promoted to replace him. Bitter fighting continued in Army Group Center's sector in the winter and early spring, with neither side being able to make much headway. The German forces held, but barely. During the summer campaign of 1942, Case Blue, the army group was to hold its position. On 30 October 1942, Kluge received a letter of good wishes from Hitler together with a cheque for a half-million Reichsmarks made out to him from the German treasury. It included