Carl Clausewitz - The Strategy of Warfare – Boxed Set

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`en Hao quotes the saying: "Birds and beasts when brought to bay will use their claws and teeth." Chang Yu 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 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. To Chung-wei was for waiting until this had abated before deciding on a final attack; but luckily another officer, Li Shou-cheng 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.

1See Col. Henderson, op. cit. vol. I. p. 426.

2For a number of maxims on this head, see "Marshal Turenne" (Longmans, 1907), p. 29.

Table of Contents

[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 (V SS. 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…. I do not know what Ts`ao Kung makes these Nine Variations out to be, but it has been suggested that they are connected with the Nine Situations" - of chapt. XI. This is the view adopted by Chang Yu. 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.]

1. Sun Tzu said: In war, the general receives his commands from the sovereign, collects his army and concentrates his forces.

[Repeated from VII. ss. 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.

[The last situation is not one of the Nine Situations as given in the beginning of chap. XI, but occurs later on (ibid. ss. 43. q.v.). Chang Yu defines this situation as being situated across the frontier, in hostile territory. Li Ch`uan 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 desperate position, you must fight. 3. There are roads which must not be followed,

["Especially those leading through narrow defiles," says Li

Ch`uan, "where an ambush is to be feared."]

armies which must be not attacked,

[More correctly, perhaps, "there are times when an army must not be attacked." Ch`en Hao says: "When you see your way to obtain a rival 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,

[Cf. III. ss. 4 Ts`ao Kung gives an interesting illustration from his own experience. When invading the territory of Hsu-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 Yu says: "No town should be attacked which, if taken, cannot be held, or if left alone, will not cause any trouble." Hsun Ying, when urged to attack Pi-yang, replied: "The city is small and well-fortified; even if I succeed intaking 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 Turenne who directed attention to the importance of marches, countermarches and maneuvers. He said: "It is a great mistake to waste men in taking a town when the same expenditure of soldiers will gain a province." 1]

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.]

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 Yu says: "Every kind of ground is characterized by certain natural features, and also gives scope for a certain variability of plan. How it is 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 war of varying his plans, even though he be acquainted with the Five Advantages, will fail to make the best use of his men.

[Chia Lin tells us that these imply five obvious and generally advantageous lines of action, namely: "if a certain road is short, it must be followed; if an army is isolated, it must be attacked; if a town is in a parlous condition, it must be besieged; if a position can be stormed, it must be attempted; and if consistent with military operations, the ruler's commands must be obeyed." But there are circumstances which sometimes forbid a general to use these advantages. For instance, "a certain road may be the shortest way for him, but if he knows that it abounds in natural obstacles, or that the enemy has laid an ambush on it, he will not follow that road. A hostile force may be open to attack, but if he knows that it is hard-pressed and likely to fight with desperation, he will refrain from striking," and so on.]

7. Hence in the wise leader's plans, considerations of advantage and of disadvantage will be blended together.

["Whether in an advantageous position or a disadvantageous one," says Ts`ao Kung, "the opposite state should be always present to your mind."]

8. If our expectation of advantage be tempered in this way, we may succeed in accomplishing the essential part of our schemes.