Hence that general is skilful in attack whose opponent does not know what to defend; and he is skilful in defense whose opponent does not know what to attack.
There is nothing more difficult than tactical maneuvering. The difficult consists in turning the devious into the direct, and misfortune into gain. Thus, to take a long and circuitous route after enticing the enemy out of the way, and though starting after him to contrive to reach the goal before him, shows knowledge of the artifice of deviation.
Nothing is more difficult than the art of maneuver. What is difficult about maneuver is to make the devious route the most direct and to turn misfortune to advantage.
If we do not wish to fight, we can prevent the enemy from engaging us even though the lines of our encampment be merely traced out on the ground. All we need to do is to throw something odd and unaccountable in his way.
Those who excel in war first cultivate their own humanity and and maintain their laws and institutions. By these means they make their governments invincible.