Variation in Tactics

Chapter 8 opens with the command structure repeated from Chapter 7 — orders from the sovereign, army assembled and concentrated — and immediately diverges into the doctrine of variation. Do not camp in difficult terrain. In areas where roads intersect, build alliances. Do not linger in exposed, isolated positions. In confined situations, use ingenuity. In desperate situations, fight. There are roads not worth taking, armies not worth attacking, cities not worth besieging, positions not worth contesting, and sovereign orders not worth obeying. The commander who understands tactical flexibility knows how to deploy troops effectively; the one who does not, even with perfect knowledge of the terrain, cannot turn that knowledge into results.

The practical doctrine: the wise leader always weighs both advantage and disadvantage together. By factoring in potential downsides when the outlook is favorable, core objectives can be accomplished. By looking for opportunities even in the middle of crisis, disaster can be escaped. Subdue rival leaders by inflicting damage; create problems for them; keep them constantly occupied; dangle attractive prospects to keep them moving. The art of war teaches not to rely on the hope that the enemy will not come, but on your own readiness — not on the chance that he will not attack, but on the certainty that your position cannot be taken.

The chapter closes with the five dangerous flaws of a commander: recklessness, which leads to destruction; cowardice, which leads to capture; a quick temper, which can be provoked by insults; over-sensitivity to shame, which can be manipulated; over-attachment to his troops, which opens him to anxiety and manipulation by the enemy. These five flaws are fatal in a commander and ruinous in war. When an army is destroyed and its leader killed, the cause will always trace back to one of them. The chapter is a warning that tactical brilliance can be undone by character, and that a commander who has not examined his own flaws has already given the enemy a weapon against him.