The essential factor of military success is speed, that is taking advantage of others' unpreparedness or lack of foresight, their failure to catch up, going by routes they do not expect, attacking where they are not on guard. This you cannot accomplish with hesitation.
Humble words and increased preparations are signs that the enemy is about to advance. Violent language and driving forward as if to the attack are signs that he will retreat.
The general who wins the battle makes many calculations in his temple before the battle is fought. The general who loses makes but few calculations beforehand.
So a military force has no constant formation, water has no constant shape: the ability to gain victory by changing and adapting according to the opponent is called genius.
When he utilizes combined energy, his fighting men become, as it were, like rolling logs or stones... The energy developed by good fighting men is as the momentum of a round stone rolled down a mountain thousands of feet in height.
Be extremely subtle, even to the point of formlessness. Be extremely mysterious, even to the point of soundlessness. Thereby you can be the director of the opponent's fate.
Generally, management of many is the same as management of few. It is a matter of organization. And to control many is the same as to control few. This is a matter of formations and signals.
So the principles of warfare are: Do not depend on the enemy not coming, but depend on our readiness against him. Do not depend on the enemy not attacking, but depend on our position that cannot be attacked.
It is the rule in war, if our forces are ten to the enemy's one, to surround him; if five to one, to attack him; if twice as numerous, to divide our army into two.
On the field of battle, the spoken word does not carry far enough; hence the institution of gongs and drums... banners and flags. Gongs and drums, banners and flags, are means whereby the ears and eyes of the host may be focused on one particular point.