28. Now a soldier’s spirit is keenest in the morning;
Always provided, I suppose, that he has had breakfast. At the battle of the Trebia, the Romans were foolishly allowed to fight fasting, whereas Hannibal’s men had breakfasted at their leisure.
by noonday it has begun to flag; and in the evening, his mind is bent only on returning to camp.
29. A clever general, therefore, avoids an army when its spirit is keen, but attacks it when it is sluggish and inclined to return. This is the art of studying moods.
30. Disciplined and calm, to await the appearance of disorder and hubbub amongst the enemy:—this is the art of retaining self-possession.
31. To be near the goal while the enemy is still far from it, to wait at ease while the enemy is toiling and struggling, to be well-fed while the enemy is famished:—this is the art of husbanding one’s strength.
32. To refrain from intercepting an enemy whose banners are in perfect order, to refrain from attacking an army drawn up in calm and confident array:—this is the art of studying circumstances.
33. It is a military axiom not to advance uphill against the enemy, nor to oppose him when he comes downhill.
34. Do not pursue an enemy who simulates flight; do not attack soldiers whose temper is keen.
35. Do not swallow a bait offered by the enemy. Do not interfere with an army that is returning home.
The commentators explain [the latter] piece of advice by saying that a man whose heart is set on returning home will fight to the death against any attempt to bar his way, and is therefore too dangerous an opponent to be tackled. Chang Yü quotes the words of Han Hsin: “Invincible is the soldier who hath his desire and returneth homewards.” A marvellous tale is told of Ts’ao Ts’ao’s courage and resource . . . : In 198 A.D., he was besieging Chang Hsiu in Jang, when Liu Piao sent reinforcements with a view to cutting off Ts’ao’s retreat. The latter was obliged to draw off his troops, only to find himself hemmed in between two enemies, who were guarding each outlet of a narrow pass in which he had engaged himself.
In this desperate plight, Ts’ao waited until nightfall, when he bored a tunnel into the mountain side and laid an ambush in it. Then he marched on with his baggage-train, and when it grew light, Chang Hsiu, finding that the bird had flown, pressed after him in hot pursuit. As soon as the whole army had passed by, the hidden troops fell on its rear, while Ts’ao himself turned and met his pursuers in front, so that they were thrown into confusion and annihilated. Ts’ao Ts’ao said afterwards, “The brigands tried to check my army in its retreat and brought me to battle in a desperate position; hence I knew how to overcome them.”
36. When you surround an army, leave an outlet free.
This does not mean that the enemy is to be allowed to escape. The object, as Tu Mu puts it, is “to make him believe that there is a road to safety, and thus prevent his fighting with the courage of despair.” Tu Mu adds pleasantly: “After that, you may crush him.”
Do not press a desperate foe too hard.
Ch’ên Hao quotes the saying, “Birds and beasts when brought to bay will use their claws and teeth.” Chang Yü says: “If your adversary has burned his boats and destroyed his cooking-pots, and is ready to stake all on the issue of a battle, he must not be pushed to extremities.” . . .
Ho Shih illustrates the meaning by a story taken from the life of Fu Yen-Ch’ing. . . . That general, together with his colleague Tu Chung-wei, was surrounded by a vastly superior army of Khitans in the year 945 A.D. The country was bare and desert-like, and the little Chinese force was soon in dire straits for want of water. The wells they bored ran dry, and the men were reduced to squeezing lumps of mud and sucking out the moisture. Their ranks thinned rapidly, until at last Fu Yen-Ch’ing exclaimed, “We are desperate men. Far better to die for our country than to go with fettered hands into captivity!”
A strong gale happened to be blowing from the northeast and darkening the air with dense clouds of sandy dust. Tu Chung-wei was for waiting until this had abated before deciding on a final attack; but luckily another officer, Li Shou-chêng by name, was quicker to see an opportunity, and said: “They are many and we are few, but in the midst of this sandstorm our numbers will not be discernible; victory will go to the strenuous fighter, and the wind will be our best ally.” Accordingly, Fu Yen-Ch’ing made a sudden and wholly unexpected onslaught with his cavalry, routed the barbarians and succeeded in breaking through to safety.
37. Such is the art of warfare.
I take it that these words conclude the extract from the Book of Army Management, which began at paragraph 23.
VIII. VARIATION OF TACTICS
There is required for the composition of a great commander not only massive common sense and reasoning power, not only imagination, but also an element of legerdemain, an original and sinister touch, which leaves the enemy puzzled as well as beaten.
Winston Churchill,
The World Crisis
(1923)
The heading means literally “The Nine Variations,” but, as Sun Tzu does not appear to enumerate these, and as, indeed, he has already told us (chapter V, paragraphs 6-11) that such deflections from the ordinary course are practically innumerable, we have little option but to follow Wang Hsi, who says that “Nine” stands for an indefinitely large number: “All it means is that in warfare we ought to vary our tactics to the utmost degree.” . . . The only other alternative is to suppose that something has been lost—a supposition to which the unusual shortness of the chapter lends some weight.