9. The Army on the March
The contents of this interesting chapter are better indicated in ss. 1 than by this heading.
1
Sun Tzu said: We come now to the question of encamping the army, and observing signs of the enemy. Pass quickly over mountains, and keep in the neighborhood of valleys.
The idea is, not to linger among barren uplands, but to keep close to supplies of water and grass. Cf. Wu Tzu, ch. 3: "Abide not in natural ovens," i.e. "the openings of valleys." Chang Yu tells the following anecdote: Wu-tu Ch`iang was a robber captain in the time of the Later Han, and Ma Yuan was sent to exterminate his gang. Ch`iang having found a refuge in the hills, Ma Yuan made no attempt to force a battle, but seized all the favorable positions commanding supplies of water and forage. Ch`iang was soon in such a desperate plight for want of provisions that he was forced to make a total surrender. He did not know the advantage of keeping in the neighborhood of valleys."