Hitler decided that an assault on Moscow would finish off the Red Army. 'Today begins the last great decisive battle of the year,' he said on 2 October 1941. The attack was made with a huge force of four armies with fourteen panzer divisions. The Germans encircled two pockets of Russians and took about 650 000 prisoners. However, autumn rains and mud slowed them down and low-gear driving used up more fuel than could be supplied. When frosts came, movement was easier but the Germans, who had not come equipped for the Russian winter, suffered from the cold. They had no winter clothing and no anti-freeze for radiators or winter oils for engines. Yet they fought their way through the Soviet defence lines. Some German infantry reached the outer bus stops of Moscow. Zhukov, who had proved to be the best Soviet general, brought up tough, warmly clad Siberian troops who held the Germans in check until the winter cold beat them. The Germans were forced to abandon their offensive on 5 December, utterly exhausted, with temperatures down to - 52'C. It was so cold that the soldiers' soup froze solid if they didn't eat it quickly.

Hitler had come very close to taking Moscow. It is difficult to say whether he would have won the war if Moscow had fallen. Stalin certainly regarded its defence as vital. He ordered the other members of the government to leave the city and to take Lenin's coffin with them, but he himself stayed.

On the day the German assault on Moscow ended, Zhukov started a massive counter-attack. The Russians fought the Germans using the same tactics as the Finns in the Winter War of 1939-40. Wearing white, they attacked the German supply lines and broke through the German positions. They had been trained to survive in the snowy forests with no shelter or fires, living off melted snow and dried millet. They then made a huge breakthrough between Demyansk and Rzhev. The fighting went on for three months in the worst of the Russian winter. For the first time in the war the Germans were fighting in defence. They used 'hedge-hogs', which were strongly defended towns or villages with guns pointing in all directions, ready to hold out if surrounded, some supplied by air. They were set in deep zones, which absorbed the impetus of the Russian attacks and halted them.