CHAPTER SUMMARY (8.01-8.16): Staying Flexible, Preparing for Multiple Eventualities
Most scholars take nine in the chapter title to mean "limitless," given Chinese tradition, which associates nine with eternity. "Nine Changes," they say, refers to the limitless possibilities of change, or variation in circumstances. There are, however, a few dependable patterns within all this variation. They're related to five types of battleground and the strategy to use on each type (with the proviso that strategies need to be adapted as circumstances change). The five types: 1) Difficult ground (terrain the army has trouble traversing, like a swamp)—leave it as soon as possible. 2) Intersecting ground (terrain on which the army is encircled by enemies and allies or prospective allies)—strengthen and maximize your alliances. 3) Open ground (terrain that your own army and the enemy's can freely cross and recross)—don't expose your troops; strive to move away from open ground. 4) Surrounded ground (terrain with only a small, narrow entrance and a circuitous or roundabout exit)—prepare for the worst possibilities; gather enough strength to withstand them. 5) Deadly ground (terrain that requires your troops to go through enemy forces)—the troops need to fight or die. Before doing battle on any ground, consider whether it's best not to fight at all and try to block your adversaries's progress. Finally, guard against personal faults in a general (rashness, cowardness, hot temper, supermorality, overfondness for the people). And remember to adhere to the Way (your side's moral purpose), even if you have to defy a superior to do so.
[8.01] Generally, the principles of warfare are: The general receives his commands from the ruler, assembles the armies, and mobilizes the masses.
[8.02] Do not camp on difficult ground. Unite with your allies on intersecting ground. Do not stay on open ground. Be prepared on surrounded ground. Do battle on deadly ground.
[8.03] There are routes not to be taken; there are armies not to be attacked; there are walled cities not to be besieged; there are grounds not to be penetrated; there are commands not to be obeyed.
[8.04] Therefore, the general who knows the advantages of the nine changes* knows how to use the troops.
[08.05] If the general does not know the advantages of the nine changes, even if he knows the lay of the land, he will not be able to take advantage of the ground.
[8.06] He who commands an army but does not know the principles of the nine changes, even if he is familiar with the five advantages,* will not be able to best use his troops.
[8.07] Therefore, the intelligent general contemplates both the advantages and disadvantages.
[8.08] Contemplating the advantages, he fulfills his calculations; contemplating the disadvantages, he removes his difficulties.*
8.04 the nine changes. The various possible circumstances. The idea here is to prepare for/know your side's advantages in the various sets of circumstances you're likely to find yourselves in.
8.06 the five advantages. Here the chapter speaks of the five factors of warfare listed on page 1.
8.08 Contemplating the advantages.... Plan for various probable scenarios so you can quickly adapt to changes (take advantage of new opportunities/prevent new difficulties from occurring).