Historians of later generations, when studying the early strategic and tactical thoughts of the Wehrmacht, often described this period with the phrase "the unity of contradictions." The reason lies in the elves' widespread recognition of the value of interior line strategy. While they considered defense as the focus of national defense, they highly extolled offense, although not to Charlemagne's extreme of "attack, attack, and more attack, death before inaction," the frequency of words like "offense," "initiative," and "crushing" in military textbooks of that time was indeed quite high.