This is coolbert: In his book, "The Art of War", Sun Tzu devotes an entire chapter to spies. Espionage in the modern terminology. Sun says that the wise sovereign and the successful general owe their victories to good intelligence. Sun says that there are five categories of spies. These are local spies, inward spies, converted spies, doomed spies, and returned spies. Employing all these types of spies will provide the intelligence necessary to win wars.

Local spies are those persons recruited from among the local populace where ever the army marches.

Inward spies are persons recruited from within the governing councils of the opposition. Civilian and military alike.

Converted spies are those spies of the enemy captured and "turned" to work for your own forces. Sent back to spy upon the opposition who they have originally worked for [without the opposition realizing this].

Doomed spies are your spies sent out with false briefings [without them knowing it] as part of an effort to deceive the enemy. The hope is that some of these doomed spies will be captured and reveal information to the enemy that is false, deceiving the enemy in the process.

Returned spies are those spies of yours that have returned from behind enemy lines, succeeding in their mission of finding the enemy troops, determining their strength, dispositions, etc.

coolbert.