In the wake of World War I, the German army lay in ruins - defeated in the war, sundered by domestic upheaval, and punished by the Treaty of Versailles. A mere twenty years later, Germany possessed one of the finest military machines in the world, capable of launching a stunning blitzkrieg attack against Poland in 1939. Well-known military historian Robert M Citino shows how Germany accomplished this astonishing reversal and developed the doctrine, tactics, and technologies that its military would use to devastating effect in World War II.