4. Now, when your weapons are dulled, your ardour damped, your strength exhausted and your treasure spent, other chieftains will spring up to take advantage of your extremity. Then no man, however wise, will be able to avert the consequences that must ensue.
Following Tu Yu, I understand 善 in the sense of “to make good,” i.e. to mend. But Tu Mu and Ho Shih explain it as “to make good plans” — for the future.
5. Thus, though we have heard of stupid haste in war, cleverness has never been seen associated with long delays.
This concise and difficult sentence is not well explained by any of the commentators. Ts‘ao Kung, Li Ch‘üan, Mêng Shih, Tu Yu, Tu Mu and Mei Yao-ch‘ên have notes to the effect that a general, though naturally stupid, may nevertheless conquer through sheer force of rapidity. Ho Shih says “Haste may be stupid, but at any rate it saves expenditure of energy and treasure; protracted operations may be very clever, but they bring calamity in their train.” Wang Hsi evades the difficulty by remarking: “Lengthy operations mean an army growing old, wealth being expended, an empty exchequer and distress among the people; true cleverness insures against the occurrence of such calamities.” Chang Yü says: “So long as victory can be attained, stupid haste is preferable to clever dilatoriness.” Now Sun Tzŭ says nothing whatever, except possibly by implication, about ill-considered haste being better than ingenious but length operations. What he does say is something much more guarded, namely that, while speed may sometimes be injudicious, tardiness can never be anything but foolish — if only because it means impoverishment to the nation. Capt. Calthrop indulges his imagination with the following: “Therefore it is acknowledged that war cannot be too short in duration. But though conducted with the utmost art, if long continuing, misfortunes do always appear.” It is hardly worth while to note the total disappearance of 拙速 in this precious concoction. In considering the point raised here by Sun Tzŭ, the classic example of Fabius Cunctator will inevitably occur to the mind. That general deliberately measured the endurance of Rome against that of Hannibal‘s isolated army, because it seemed to him that the latter was more likely to suffer from a long campaign in a strange country. But it is quite a moot question whether his tactics would have proved successful in the long run. Their reversal, it is true, led to Cannae; but this only establishes a negative presumption in their favour.