The general receives his commands from the sovereign, collects an army, and concentrates his forces. Before he pitches camp he must blend and harmonise the different elements. After that comes tactical manoeuvring, than which there is nothing more difficult, because the difficulty consists in turning the devious into the direct, and misfortune into gain. To take a long and circuitous route, after enticing the enemy out of the way, and though starting after him to reach the goal before him, shows knowledge of the artifice of deviation. Manoeuvring with an army is advantageous. With an undisciplined multitude it is most dangerous.
A fully equipped army set in march to snatch an advantage will likely be too late. A flying column detached for the same purpose sacrifices its baggage and stores. Order the men to roll up their buff-coats and make forced marches without halting day or night, covering a hundred li to wrest an advantage, and the leaders of all three divisions fall into the hands of the enemy. The stronger men are in front, the jaded ones fall behind, and only one-tenth of the army reaches its destination. March fifty li to outmanoeuvre the enemy, and the leader of the first division is lost, with only half the force arriving. March thirty li with the same object, and two-thirds arrive. An army without its baggage-train is lost. Without provisions it is lost. Without bases of supply it is lost. Alliances cannot be entered until the designs of neighbours are known. An army is not fit to be led on the march unless its general is familiar with mountains and forests, pitfalls and precipices, marshes and swamps, and makes use of local guides.
In war, practise dissimulation and you will succeed, and move only if there is a real advantage to be gained. Whether to concentrate or to divide must be decided by circumstances. Rapidity is that of the wind, compactness that of the forest, raiding and plundering like fire, immovability like a mountain. Plans stay dark and impenetrable as night, and the move falls like a thunderbolt. Spoil taken from a countryside is divided amongst the men. Captured territory is cut into allotments for the soldiery. He will conquer who has learnt the artifice of deviation.
On the field the spoken word does not carry, so gongs and drums are instituted, and ordinary objects cannot be seen clearly, so banners and flags are instituted. Ears and eyes lock on one point. Then the brave cannot advance alone, and the cowardly cannot retreat alone. That is how a large mass is handled as one body. The same attention turns on mood. A soldier's spirit is keenest in the morning, flags by noonday, and by evening wants only the camp, so the clever general avoids an army while its spirit is keen and attacks it when it is sluggish and inclined to return. He can also be robbed of a whole army's spirit, and a commander-in-chief can be robbed of his presence of mind. He stays calm while the enemy falls into hubbub, near the goal while the enemy is still far, and well-fed while the enemy is famished. Banners in perfect order are not intercepted. A simulated flight is not pursued. A bait is not swallowed. An army returning home is left alone. When he surrounds an army, he leaves an outlet free, and he does not press a desperate foe too hard.
