But no doubt it was the discipline and common outlook instilled by those traditions that enabled them to have that degree of sympathy and mutual trust that was necessary to produce the years of miracles later on. Sad to say politically able but unscrupulous men displaced the Reichswehr as the chief power in the land, and turned it into the servant of tyranny. But there it is, soldiers are seldom a match for politicians on their home ground. The lesson however seems to me plain for all to see, namely, that a disciplined body of men with a common outlook and mutual trust and understanding will drive a body which does not have those advantages before them like cattle. I believe this is true not only in war, but in our civilian world as well. Once you have undermined the power and coherence of autonomous bodies like the professions and the trade unions, you must not expect the reign of sweet reasonableness to descend; you have merely cleared the way for the most ruthless and the most organised.
This, then, is the true psychology which people should study: the rules of conflict in a world almost obsessed by conflict. It is not as though there is anything new about them. The rules of conflict have been well understood ever since a Chinese gentleman, called Mr. Tze Sun, wrote a book called The Thirteen Chapters in about 400 BC. Lest anyone should think the ancients not worth listening to, he was writing at the end of a monumental civil war in China, so he was writing from experience. He was also writing about the time of a distinguished contemporary, Alexander the Great, who achieved against the Persians a blitzkrieg more accomplished than anything General Guderian achieved in 1940. Alexander's attack struck at and paralysed the enemy's will; he did not merely carve up their forces in the field. General Fuller envisaged how tanks might be used to recreate this attack against the enemy's will, as he saw a splendid British army reduced to a rabble in the retreat of March 1918.