At the end of 1942, when the Wehrmacht could advance no further east, Hitler switched German ground forces from an “enemy force-oriented” strategy to a “ground-holding” strategy. Hitler demanded that his armies defend vast, largely empty and irrelevant stretches of Soviet territory. “Holding ground” not only robbed the German military of its ability to exercise operational discretion, and, above all, to outmaneuver the slow, methodical Soviet opponent; holding ground also pushed German logistics to the breaking point. When holding ground was combined with endless counterattacks to retake useless territory, the Wehrmacht was sentenced to slow, grinding destruction. Ukrainian President Volodymyr...