Using Spies

1. Sun Tzŭ said: Raising a host of a hundred thousand men and marching them great distances entails heavy loss on the people and a drain on the resources of the State. The daily expenditure will amount to a thousand ounces of silver. There will be commotion at home and abroad, and men will drop down exhausted on the highways. As many as seven hundred thousand families will be impeded in their labor.

1. Sun Tzu said: Raising an army of a hundred thousand men and marching them long distances places heavy burdens on the people. It also drains the state's resources. Daily spending will reach a thousand ounces of silver. There will be turmoil at home and abroad, and men will collapse from exhaustion on the roads. As many as seven hundred thousand families will have their work disrupted.

2. Hostile armies may face each other for years, striving for the victory which is decided in a single day. This being so, to remain in ignorance of the enemy’s condition simply because one grudges the outlay of a hundred ounces of silver in honours and emoluments, is the height of inhumanity.

2. Enemy armies may face each other for years, seeking a victory decided in a single day. Given this, remaining ignorant of the enemy’s situation simply because you resent spending money is the height of inhumanity. The expense is a hundred ounces of silver in honors and payments.

3. One who acts thus is no leader of men, no present help to his sovereign, no master of victory.

3. Anyone who acts this way is no leader of men. He offers no help to his ruler and has no mastery of victory.

4. Thus, what enables the wise sovereign and the good general to strike and conquer, and achieve things beyond the reach of ordinary men, is foreknowledge.

4. So a wise ruler and a good general can attack, conquer, and achieve things beyond ordinary people’s reach because of foreknowledge.

5. Now this foreknowledge cannot be elicited from spirits; it cannot be obtained inductively from experience, nor by any deductive calculation.

5. Now this advance knowledge cannot come from spirits. Nor can it come from generalizing past experience or from logical calculations.

6. Knowledge of the enemy’s dispositions can only be obtained from other men.

6. You can learn about the enemy’s positions and arrangements only from other people.

7. Hence the use of spies, of whom there are five classes: (1) Local spies; (2) inward spies; (3) converted spies; (4) doomed spies; (5) surviving spies.

7. This is why spies are used. There are five types: (1) local spies, (2) insider spies, (3) turned spies, (4) doomed spies, (5) surviving spies.

8. When these five kinds of spy are all at work, none can discover the secret system. This is called “divine manipulation of the threads.” It is the sovereign’s most precious faculty.

8. When all five kinds of spy are at work, no one can uncover the secret system. Using them together is called “divine manipulation of the threads.” This is the ruler’s most precious skill.

9. Having local spies means employing the services of the inhabitants of a district.

9. Having local spies means using the services of people who live in the area.

10. Having inward spies, making use of officials of the enemy.

10. Using inward spies means using the enemy's officials as spies.

11. Having converted spies, getting hold of the enemy’s spies and using them for our own purposes.

11. Using converted spies means capturing the enemy’s spies and using them for our own purposes.

12. Having doomed spies, doing certain things openly for purposes of deception, and allowing our own spies to know of them and report them to the enemy.

12. Using doomed spies means openly doing certain things to deceive the enemy. We let our own spies learn of these actions and report them to the enemy.

13. Surviving spies, finally, are those who bring back news from the enemy’s camp.

13. Surviving spies are the final type: those who bring back information from the enemy’s camp.

14. Hence it is that with none in the whole army are more intimate relations to be maintained than with spies. None should be more liberally rewarded. In no other business should greater secrecy be preserved.

14. So no one in the whole army should have closer relationships with the commander than spies. No one should be rewarded more generously. No other work should be kept more secret.

15. Spies cannot be usefully employed without a certain intuitive sagacity.

15. Spies cannot be used effectively without a certain amount of intuition and good judgment.

16. They cannot be properly managed without benevolence and straightforwardness.

16. They cannot be managed properly without kindness and honesty.

17. Without subtle ingenuity of mind, one cannot make certain of the truth of their reports.

17. Without a sharp, resourceful mind, you cannot be certain their reports are true.

18. Be subtle! be subtle! and use your spies for every kind of business.

18. Be subtle! Be subtle! And use your spies for every kind of task.

19. If a secret piece of news is divulged by a spy before the time is ripe, he must be put to death together with the man to whom the secret was told.

19. If a spy reveals secret information too soon, both he and the man he told must be put to death.

20. Whether the object be to crush an army, to storm a city, or to assassinate an individual, it is always necessary to begin by finding out the names of the attendants, the aides-de-camp, the door-keepers and sentries of the general in command. Our spies must be commissioned to ascertain these.

20. Whether you aim to crush an army, storm a city, or assassinate someone, you must always begin the same way. Find the names of the commanding general’s attendants, military aides, gatekeepers, and sentries. Our spies must be assigned to uncover these names.

21. The enemy’s spies who have come to spy on us must be sought out, tempted with bribes, led away and comfortably housed. Thus they will become converted spies and available for our service.

21. We must find the enemy spies sent to spy on us. We must tempt them with bribes, lead them away, and give them comfortable housing. This will turn the enemy spies into double agents available to serve us.

22. It is through the information brought by the converted spy that we are able to acquire and employ local and inward spies.

22. Information from an enemy spy we have turned lets us recruit and use local spies and enemy insiders.

23. It is owing to his information, again, that we can cause the doomed spy to carry false tidings to the enemy.

23. Again, his information allows us to make the doomed spy carry false reports to the enemy.

24. Lastly, it is by his information that the surviving spy can be used on appointed occasions.

24. Finally, his information allows the surviving spy to be used at the appointed times.

25. The end and aim of spying in all its five varieties is knowledge of the enemy; and this knowledge can only be derived, in the first instance, from the converted spy. Hence it is essential that the converted spy be treated with the utmost liberality.

25. The goal of all five types of spying is to gain knowledge of the enemy. This knowledge must first come from an enemy spy who has been won over. So it is essential to treat that spy with the greatest generosity.

26. Of old, the rise of the Yin dynasty was due to I Chih who had served under the Hsia. Likewise, the rise of the Chou dynasty was due to Lü Ya who had served under the Yin.

26. In ancient times, the Yin dynasty rose because of I Chih, who had served under the Hsia. Likewise, the Chou dynasty rose because of Lü Ya, who had served under the Yin.

27. Hence it is only the enlightened ruler and the wise general who will use the highest intelligence of the army for purposes of spying and thereby they achieve great results. Spies are a most important element in war, because on them depends an army’s ability to move.

27. So only an enlightened ruler and a wise general will use the army’s most intelligent people as spies. By doing so, these leaders achieve great results. Spies are vital in war because an army’s ability to move depends on them.