If you march thirty li with the same object, two-thirds of your army will arrive.
In the T‘ung Tien is added: 以是知軍爭之難 “From this we may know the difficulty of manœuvring.”
11. 是故軍無輜重則亡無糧食則亡無委積則亡
We may take it then that an army without its baggage-train is lost; without provisions it is lost; without bases of supply it is lost.
委積 is explained by Tu Yu as 芻草之屬 “fodder and the like;” by Tu Mu and Chang Yü as 財貨 “goods in general;” and by Wang Hsi as 薪鹽蔬材之屬 “fuel, salt, foodstuffs, etc.” But I think what Sun Tzŭ meant was “stores accumulated in dépôts,” as distinguished from 輜重 and 糧食, the various impedimenta accompanying an army on its march. Cf. Chou Li, ch. xvi. fol. 10: 委人 ... 斂薪芻凡疏材木材凡畜聚之物.
12. 故不知諸侯之謀者不能豫交
We cannot enter into alliances until we are acquainted with the designs of our neighbours.
豫 = 先. Li Ch‘üan understands it as 備 “guard against,” which is hardly so good. An original interpretation of 交 is given by Tu Mu, who says it stands for 交兵 or 合戰 “join in battle.”
13. 不知山林險阻沮澤之形者不能行軍
We are not fit to lead an army on the march unless we are familiar with the face of the country—its mountains and forests, its pitfalls