[Tu Mu cites the famous march of Chao She in 270 B.C. to relieve the town of O-yu, which was closely invested by a Ch’in army. The King of Chao first consulted Lien P’o on the advisability of attempting a relief, but the latter thought the distance too great, and the intervening country too rugged and difficult. His Majesty then turned to Chao She, who fully admitted the hazardous nature of the march, but finally said: "We shall be like two rats fighting in a whole—and the pluckier one will win!" So he left the capital with his army, but had only gone a distance of 30 _li_ when he stopped and began throwing up entrenchments. For 28 days he continued strengthening his fortifications, and took care that spies should carry the intelligence to the enemy. The Ch’in general was overjoyed, and attributed his adversary’s tardiness to the fact that the beleaguered city was in the Han State, and thus not actually part of Chao territory. But the spies had no sooner departed than Chao She began a forced march lasting for two days and one night, and arrive on the scene of action with such astonishing rapidity that he was able to occupy a commanding position on the "North hill" before the enemy had got wind of his movements. A crushing defeat followed for the Ch’in forces, who were obliged to raise the siege of O-yu in all haste and retreat across the border.] 5. Manœuvering with an army is advantageous; with an undisciplined multitude, most dangerous. [I adopt the reading of the _T’ung Tien_, Cheng Yu-hsien and the _T’u Shu_, since they appear to apply the exact nuance required in order to make sense. The commentators using the standard text take this line to mean that manœuvers may be profitable, or they may be dangerous: it all depends on the ability of the general.] 6. If you set a fully equipped army in march in order to snatch an advantage, the chances are that you will be too late. On the other hand, to detach a flying column for the purpose involves the sacrifice of its baggage and stores. [Some of the Chinese text is unintelligible to the Chinese commentators, who paraphrase the sentence. I submit my own rendering without much enthusiasm, being convinced that there is some deep-seated corruption in the text. On the whole, it is clear that Sun Tzŭ does not approve of a lengthy march being undertaken without supplies. Cf. infra, § 11.] 7. Thus, if you order your men to roll up their buff-coats, and make forced marches without halting day or night, covering double the usual distance at a stretch, [The ordinary day’s march, according to Tu Mu, was 30 _li_; but on one occasion, when pursuing Liu Pei, Ts’ao Ts’ao is said to have covered the incredible distance of 300 _li_ within twenty-four hours.] doing a hundred _li_ in order to wrest an advantage, the leaders of all your three divisions will fall into the hands of the enemy.