A major military operation is a severe drain on the nation, and may be keptup for years in the struggle for one day's victory. So to fail to know theconditions of opponents because of reluctance to give rewards forintelligence is extremely inhumane, uncharacteristic of a true militaryleader, uncharacteristic of an assistant of the government, uncharacteristicof a victorious chief. So what enables an intelligent government and awise military leadership to overcome others and achieve extraordinaryaccomplishments is foreknowledge.
Foreknowledge cannot be gotten from ghosts and spirits, cannot be had byanalogy, cannot be found out by calculation. It must be obtained frompeople, people who know the conditions of the enemy.
There are five kinds of spy: The local spy, the inside spy, the reversespy, the dead spy, and the living spy. When the five kinds of spies areall active, no one knows their routes - this is called organizationalgenius, and is valuable to the leadership.
Local spies are hired from among the people of a locality. Inside spiesare hired from among enemy officials. Reverse spies are hired from amongenemy spies. Dead spies transmit false intelligence to enemy spies.Living spies come back to report.
Therefore no one in the armed forces is treated as familiarly as are spies,no one is given rewards as rich as those given to spies, and no matter ismore secret than espionage.
One cannot use spies without sagacity and knowledge, one cannot use spieswithout humanity and justice, one cannot get the truth from spies withoutsubtlety. This is a very delicate matter indeed. Spies are usefuleverywhere.
If an item of intelligence is heard before a spy reports it, then both thespy and the one who told about it die.
Whenever you want to attack an army, besiege a city, or kill a person,first you must know the identities of their defending generals, theirassociates, their visitors, their gatekeepers, and their chamberlains, soyou have your spies find out.
You must seek out enemy agents who have come to spy on you, bribe them andinduce them to stay with you, so you can use them as reverse spies. Byintelligence thus obtained, you can find local spies and inside spies toemploy. By intelligence thus obtained, you can cause the misinformation ofdead spies to be conveyed to the enemy. By intelligence thus obtained, youcan get living spies to work as planned.
It is essential for a leader to know about the five kinds of espionage, andthis knowledge depends on reverse spies, so reverse spies must be treatedwell.
So only a brilliant ruler or a wise general who can use the highlyintelligent for espionage is sure of great success. This is essential formilitary operations, and the armies depend on this in their actions.
