Secret operations are essential in war; upon them the army relies to make its every move.

This does not mean that the enemy is to be allowed to escape. The object is to make him believe that there is a road to safety, and thus prevent his fighting with the courage of despair. After that, you may crush him.

There are five kinds of incendiary attack: The first is called setting fire to personnel; the second, to stores; the third, to transport vehicles and equipment; the fourth, to munitions; the fifth, to supply installations...In all cases an army must understand the changes induced by the five kinds of incendiary attack, and make use of logistical calculations to address them.

From a position of this sort, if the enemy is unprepared, you may sally forth and defeat him. But if the enemy is prepared for your coming, and you fail to defeat him, then, return being impossible, disaster will ensue.

Of all rewards none [is] more liberal than those given to secret agents.

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.

He whose ranks are united in purpose will be victorious.