First Mention of Espionage

The first mention of espionage (chōhō) is in Sun Tzu’s The Art of War, the Chinese classic on warfare. In ancient China, it was common to achieve victory with incredible numbers of troops. But the consequences were catastrophic for the landscape and structure. Countless, long, bloody battles lasting several generations were fought, killing thousands.

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. […] Hostile armies may face each other for years, strivingfor 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.

Sun Tzu, The Art of War

The Art of War

Even today, generals often prefer long campaigns with high human and material costs. Positions are excavated and people entrench themselves. But a single spy or saboteur’s accomplishments could shorten the war by years.

Laws on Warfare?

War is an unacceptable state of affairs, and a Ninja could never allow his master to start a war. However, when the freedom of one’s country is being attacked by others and one is forced to defend oneself, a Ninja strives to do whatever it takes to end the conflict as quickly as possible.

It is therefore questionable what kind of world we live in when rules for war are being established today. It’s not a game!

Of course, it is understandable that some rules need to ensure that civilians are protected from massacres, but it is questionable whether rules are of any use when dictators and tyrants do not comply with them anyway. And as always, the victor of war decides on punishment. Because winners will probably have to answer before any court in the rarest of cases.

So I find it very concerning that espionage and sabotage are considered vile and contemptible in these laws of war, but long-range missile launches, tank battles, and infantry are considered part of normal warfare.

Espionage to Shorten the War

It has been proven time and time again that these despicable spies have saved the lives of hundreds of thousands of soldiers. They restored the balance of nuclear power, stole the Enigma machine, and saved thousands of supply ships from being sunk. The famous British Commandos, by their acts of sabotage, gave Britain a respite after the German invasion. They blew up ship and submarine yards, scouted targets for the bombers, and prevented weapons of mass destruction like V2 from going into mass production. And a German spy found out for the Russians that the Japanese were not planning an invasion of Russia. In this way, Stalin was able to send his troops to Germany with all their strength and end the war with the help of the Allies.

Everyone should think about this and think about who defines right and wrong and what interests they are pursuing.


An important basis for espionage is anonymity. This was the Ninja’s recipe for success, which was also called (mumei mugei no jutsu, Engl. No art, no name). To protect his anonymity, the Ninja made sure no one knew his real face.

When threatened with capture, he has cut his face to avoid identification or cut out his tongue to avoid revealing anything. Sometimes two Ninja were together on a mission. If one was caught, the other had the order to kill his comrade.

A principle of the Ninja (yomogami no jutsu, Engl. a hairstyle, viewed from four different sides, must always look the same) states that one should always choose several names and identities. The famous jōnin Momochi Sandayu even had two different families with children and a house. He was also the jōnin Fujibayashi Nagato. So one person led two different groups of Ninja.

The reason for espionage is to gain an advantage in war. You can find out the strength, armament, etc. of the enemy as pure reconnaissance, and thus plan your campaigns better.

Types of Espionage

This can be divided into two areas: espionage in peacetime (tōiri) and espionage and sabotage during the war (chi kai ri).

When spying or planning an act of sabotage, there were six different points to consider for the successful completion of a mission:

Place a Ninja

A Ninja had to remain unnoticed and unnoticeable throughout their mission. To do this, he had to adopt the most normal appearance possible.

One possibility was to place agents in possible war or unrest areas during peacetime. It was certainly far easier to assimilate into and subvert a society in times of peace.

The Ninja settled into his area of ​​operations and became a part of society. He made contacts, sounded out possible allies, held a lot of conversation, observed objects, and worked his way into the necessary information.

Whenever possible, he and his agents filled important key positions in the military or communications. In times of war, this is hardly possible because the checks are too strong.

He could also draw maps, enabling troops to move more easily in times of war.

Another option was to confuse the enemy or leave them in the dark. A sense of security was created in his mind. You could have an agent intercepted with information. The informant then carried documents with him, but they only contained false or incorrect information. In this way, you could get rid of a traitor in your ranks if you knowingly provided him with false information.


Five different types of spies could be used on an espionage or sabotage mission:

  • Native Spies – He was at home in the area of ​​operations and therefore knew the geography, language, customs, and inhabitants. Such a spy was not easy to disguise because he was well known.
  • Inside Spies – Recruiting a spy from the opposing team was called an Inside Spy. Men who had been demoted, criminals who had been punished, greedy people.
  • Surviving Spies – If a spy entered enemy territory only for the duration of his mission and returned home after completing it, that was called a surviving spy.
  • Defected Spies – An enemy spy who had switched sides and was now working for your side was called a defected spy or double agent. However, such an agent is always a big risk because his loyalty could change again and he could only be a double agent for the other side.
  • Doomed Spies – A spy who for whatever reason fell out of favor with his master, or who turned out to be a traitor or double agent, was sent to his death. You could supply him with false information for a while beforehand and then you could usually use him to carry out one last ruse with his help.


You could also position kunoichi in the enemy’s area of ​​operations. They were usually not touched and could get closer to generals and Samurai. They used their intuition, psychology, and manipulation to achieve their goal. A distinction was made between two different types of kunoichi:

  • Shimma kunoichi – This kunoichi was a female member of a Ninja-Ryū. She had received combat training and had been trained in special tactics and strategies. Usually, a male kantō kusha (commander) led a group of kunoichi. He supported them, took their information, and helped them when an escape was needed.
  • Karima kunoichi – There were numerous women who knowingly or unknowingly brought information to the kunoichi. This kunoichi had seldom received brief instruction in espionage. Both women from the castle area and women of lower status (prostitutes, farmers) kept a kunoichi as informants.

Using the Services of Traitors

Another possibility was to use the enemy’s people for his purposes. The dissatisfied were sought out and instigated to betrayal. This became the principle of gojō goyoku (manipulation by the five desires). Of course, one high-ranking traitor was far more valuable than another. But the Ninja also sought help and support from the population, mostly in times of peace. This is how a Ninja could support a family financially in peacetime. In times of war, this had to be at his service. They had to give the Ninja their house as a shelter, perform minor informant and espionage duties, or perhaps even give their daughter to the enemy prince as a concubine to gain access to the fortress.

Sometimes two agents were sent on the same mission without the knowledge of the other. On the one hand, you had greater objectivity to what was happening, on the other hand, you could easily unmask double agents in this way.

Once you uncovered an enemy agent, you could feed them false information for a while and then discredit them with their masters by blatant deception, either killing them or defecting to them.

One could also use one’s agent, who parted with his old master after an apparent quarrel or for higher money. He enlisted with the enemy and worked for them for a while. It is even said that a Ninja killed some Ninja of his clan on behalf of the enemy master before he completed his task and returned to his old master.

A favorite tactic of the Ninja (kami gakure no jutsu, Engl. the art of hiding behind God) was to use detours to approach the goal. If the target object was too heavily guarded, then the Ninja found out about the relatives of his target object in the Buddhist or Shintoist temple. He tried to befriend a relative or close confidante. In this way, sooner or later, he came close to his goal.

Determine Goals

Next, the Ninja had to figure out the enemy’s targets. For this purpose, a team observed the enemy territory over a longer period.

Closer spies might know more about the enemy’s plans. He gained access to top-secret rooms and documents and tried to see through his opponent.

Determine Strategies

Then the enemy’s strategies had to be recognized and analyzed. One had to find out which people held key positions, which codes and keywords were used by the guards, how supplies reached the enemy, which routes and routes were used by patrols and soldiers. And the Ninja had to expose and, if possible, hinder or destroy the enemy’s espionage system.

Sowing Confusion

You had to confuse the enemy and confuse them with false information, rumors, and fake communications. During this phase, the Ninja also attempted to encourage discord and discontent among the soldiers, playing them off against one another. For example, he could come as a survivor into the castle of the enemy and tell of a campaign, of troops and movements that in reality did not take place or took place somewhere else. Or he frightens the soldiers with reports of nocturnal murders in other camps. In this way, the soldiers could no longer sleep and their motivation and readiness dropped.

Determine Tactics

The Ninja also lay down on observation posts to find out the battle tactics, battle strategies, strengths, and weaknesses of the opponent. He figured out how to place and move his troops, explored troop strength, armament, and the enemy general’s secret techniques and tactics. He found out where and when supplies were arriving and if there were other troops nearby to support them. If a commander had bad tendencies in warfare, the Ninja would support those tendencies.

If he for example splintered his forces, this process was encouraged, if his front was weak, then one tried to urge the general to charge through the weak front. If the enemy had a strong center, the Ninja advised the general to hit the sides and roll up the troops from behind.


At the same time, he had to try to keep his strategies secret from his opponents. Important documents were sent to a possible suspicious person and one waited to see how they reacted (yamabiko shicho no jutsu, Engl. the art of listening for the echo). Once the enemy spies were identified, it was a matter of deciding whether to eliminate them or let them live. If he was allowed to live, of course, he was being given false information on purpose. The fighting techniques of the Ryū were also kept strictly secret. In some Ryū, there were even techniques to show to strangers that were invented solely for deception.

You convinced your general to try out new techniques and issue non-standard orders. In this way, one could leave the enemy in the dark about the truth until the decisive moment.

Text: Stefan Imhoff