1. Sun Tzu said: In war, the general receives his commands from the sovereign, collects his army and concentrates his forces.
Repeated from chapter VII, paragraph 1, where it is certainly more in place. It may have been interpolated here merely in order to supply a beginning to the chapter.
2. When in difficult country, do not encamp. In country where high roads intersect, join hands with your allies. Do not linger in dangerously isolated positions.
Chang Yü [defines the last-named situation as being] situated across the frontier, in hostile territory. Li Ch’üan says it is “country in which there are no springs or wells, flocks or herds, vegetables or firewood”; Chia Lin, “one of gorges, chasms and precipices, without a road by which to advance.”
In hemmed-in situations, you must resort to stratagem. In a desperate position, you must fight.
Chang Yü has an important note here. . . . : “The reason why only five [of the nine variations] are given is that the subject is treated
en précis
... All kinds of ground have corresponding military positions, and also a variation of tactics suitable to each. . . . [But] he wishes here to speak of the Five Advantages, so he begins by setting forth the Nine Variations. These are inseparably connected in practice, and therefore they are dealt with together.” The weak point of this argument is the suggestion that “five things” can stand as . . . an abstract or abridgment of nine, when those that are omitted are not less important than those that appear, and when one of the latter is not included amongst the nine at all.
3. There are roads which must not be followed,
“Especially those leading through narrow defiles,” says Li Ch’üan, “where an ambush is to be feared.”
armies which must not be attacked,
More correctly, perhaps, “there are times when an army must not be attacked.” Ch’ên Hao says: “When you see your way to obtain a trivial advantage, but are powerless to inflict a real defeat, refrain from attacking, for fear of overtaxing your men’s strength.”
towns which must not be besieged,
Ts’ao Kung gives an interesting illustration from his own experience. When invading the territory of Hsü-chou, he ignored the city of Hua-pi, which lay directly in his path, and pressed on into the heart of the country. This excellent strategy was rewarded by the subsequent capture of no fewer than fourteen important district cities. Chang Yü says: “No town should be attacked which, if taken, cannot be held, or if left alone, will not cause any trouble.” Hsün Ying, when urged to attack Pi-yang, replied: “The city is small and well-fortified; even if I succeed in taking it, it will be no great feat of arms; whereas if I fail, I shall make myself a laughing-stock.”
In the seventeenth century, sieges still formed a large proportion of war. It was [Marshal] Turenne who directed attention to the importance of marches, countermarches and manœuvres. He said: “It is a great mistake to waste men in taking a town when the same expenditure of soldiers will gain a province.”
positions which must not be contested, commands of the sovereign which must not be obeyed.
This is a hard saying for the Chinese, with their reverence for authority, and Wei Liao Tzu (quoted by Tu Mu) is moved to exclaim: “Weapons are baleful instruments, strife is antagonistic to virtue, a military commander is the negation of civil order!” The unpalatable fact remains, however, that even Imperial wishes must be subordinated to military necessity.
I’ve always taken it for granted that the Führer left the command of the army to me. This crazy order has come like a bombshell. He can’t just blindly apply experience he gained in Russia to the war in Africa. He should have left the decision here to me. . . . Until this moment, we in Africa had always had complete freedom of action. Now that was over. . . . An overwhelming bitterness welled up in us when we saw the superlative spirit of the army, in which every man, from the highest to the lowest, knew that even the greatest effort could no longer change the course of battle.
Field Marshal Rommel, on Adolf Hitler’s interference and the German defeat at El Alamein (1942)
4. The general who thoroughly understands the advantages that accompany variation of tactics knows how to handle his troops.
5. The general who does not understand these, may be well acquainted with the configuration of the country, yet he will not be able to turn his knowledge to practical account.
Literally, “get the advantage of the ground,” which means not only securing good positions, but availing oneself of natural advantages in every possible way. Chang Yü says: “Every kind of ground is characterised by certain natural features, and also gives scope for a certain variability of plan. How is it possible to turn these natural features to account unless topographical knowledge is supplemented by versatility of mind?”
6. So, the student of war who is unversed in the art of varying his plans, even though he be acquainted with the Five Advantages, will fail to make the best use of his men.