In this book a man who has made history—on a great scale—gives us his own story of how he shaped it by means of a new idea, and how it led to an end he had not foreseen. Guderian had a tremendous impact on the course of events in our time. Without him it is probable that Hitler would have met early frustration in his offensive efforts when he embarked on war. For in 1939-40 Germany's forces in general were not sufficient to overcome any major Power. Her opening run of victory in the Second World War was only made possible by the panzer forces that Guderian had created and trained, and by his audacious leading of those forces in disregard of his superiors' caution as well as Hitler's fears. Guderian's break-through at Sedan and lightning drive to the Channel coast virtually decided the issue of the Battle of France.
A year later, the drive he led into the East came close to producing the complete collapse of Russia's armies, but this time renewed hesitancy on top imposed a delay that spun out the campaign until winter intervened, and gave the Russians a breathing-space for recovery. Stalin was able to raise fresh armies and develop new arms factories to replace those that had been captured. Russia's strength went on increasing, while Germany was never again as strong as in that first campaign. Hitler's 1942 effort, though dangerous, was a more limited one than in the previous year. After the failure at Stalingrad the decline of the Germans' power became manifest to all, while America's entry into the war definitely ensured their downfall.