American military historian Colonel David Glantz explores the causes and consequences of the Battle of Smolensk, which is a series of military operations that unfolded in Central Russia in the Smolensk region. For more than two months, the troops of the Western, Central, Reserve and Bryansk Fronts of the Red Army fought with the forces of the German Army Group Center. This difficult confrontation ended in a strategic victory for the Red Army. Reproducing the events near Smolensk, Glanz uses exclusively documentary materials. In the course of his research, he comes to the conclusion that the damage inflicted on the Wehrmacht by the Red Army during the counter-offensive in this area was so significant that it determined and hastened the defeat of Germany at the gates of Moscow in December 1941. Which, in turn, contributed to the failure of the operation “ Barbarossa" and the eventual collapse of the Wehrmacht. The narrative is illustrated by authentic German tactical maps. The appendix provides comprehensive information about the state of the Wehrmacht and Red Army troops.