Perfidy is a kind of deception wherein someone promises to do the right thing, but has every intention of breaking that promise later on. An example of perfidy, most commonly thought of in terms of war, is an enemy raising a flag as a symbol of truce, only to attack the opposing side as they come forward to meet. Perfidy is prosecuted as a war crime because it takes advantage of the protections that are in place to benefit every American citizen. To explore this concept, consider the following perfidy definition.

Definition of Perfidy


  1. An act of treachery or faithlessness.
  2. A deliberate breach of someone’s trust.


1585-1595       Latin   perfidia    (beyond the limits of faith)

What is Perfidy

Perfidy is a form of trickery wherein one party makes a promise in good faith, while fully intending to break that promise later on. Perfidy is often seen in wartime, as one side lures the other into a false sense of security, only to break that trust later on when attempting to gain a tactical advantage. An example of perfidy occurred during World War II, when Japanese soldiers booby-trapped their dead or wounded, or fake a surrender or injury, in order to lure Allied soldiers in for an attack.

Perfidy is different from treachery in that, while perfidy is based on encouraging someone to believe a lie, treachery involves an act of deliberately and directly trying to hurt someone. In international law, however, the two terms are used interchangeably. Other examples of perfidy include:

  • Pretending to offer a negotiation under a flag of truce or surrender
  • Pretending to be incapacitated due to an illness or injury
  • Pretending to be a civilian when one is, in fact, a soldier for the opposition

Article 39 of the Geneva Conventions prohibits the use of flags, military emblems, or uniforms of the opposing side during an attack, as a way of either protecting their own forces, or obstructing the enemy’s military operations. The Geneva Conventions are rules, which apply only during wartime, meant to protect those who are not taking part in the war. This includes soldiers who are sick and wounded on the field or at sea, along with civilians and prisoners of war (POWs).

Ruses of War Under the Geneva Conventions

Article 37 of the Geneva Conventions specifically refers to what are called “ruses of war.” Ruses of war are not considered to be perfidy, even though they are technically duping the enemy into believing an untruth. Examples of ruses of war include camouflage, decoys, faked operations, or misinformation. The point of a ruse of war is either mislead the enemy, or to trap him by encouraging him to act in a reckless manner.

However, what separates ruses of war from perfidy is that they do not infringe upon the international laws that pertain to war, and they do not try to set up a false sense of security, using internationally recognized symbols or acts of truce, only to deliberately lead the enemy into a trap. Instead, ruses are used in the hopes that the enemy will take it upon himself to walk right into a trap, such as when soldiers are camouflaged and lying in wait. Ruses are, by comparison, more harmless and indirect than are acts of perfidy.

Disguising Military Equipment

When it comes to disguising military equipment during wartime, there is a fine line between what can be considered legal, and what is considered perfidy. What follows are some of the more commonly used military equipment actions during wartime, and the circumstances under which disguising military equipment may or may not be considered perfidy:

Launching a Missile from Above

Aerial attacks – or missiles launched from above – are only legal when launched from a clearly marked military platform. This is true, whether the platform is an airplane, or a ground- or sea-based launching platform. Dropping a bomb, or launching a missile or other attack from a platform that is pretending to be a civilian vehicle or platform is considered perfidy – even if the people on the ground cannot identify the markings.

Ambushes and Sniper Attacks

Snipers are not permitted to disguise themselves as civilians, or as any other persona, in a deliberate attempt to trick the enemy. For instance, a soldier cannot disguise himself as a member of the Red Cross. Interestingly, snipers are also not permitted to shoot from civilian objects, such as church towers. In a similar fashion to the launching of a missile, even though the person who is hit by the sniper will, in all likelihood, not be able to identify the sniper, or where the bullet came from, it is illegal for a sniper to ambush the enemy by “masquerading” as a civilian.

Improvised Explosive Devices (IEDs)

IEDs have been confusing in the past because there are a lot of different factors at work that could potentially constitute perfidy. For instance, some could argue that it is an act of perfidy to place an IED in something “civilian,” like the grass or sand near a roadside. However, the argument against perfidy is that there is a clear difference between something like grass that does not look “military” under normal circumstances, and disguising military equipment by hiding it in a civilian house.

The former is more similar to a booby-trap and, in that case, it can be argued that an IED is specifically targeting an individual, rather than harming individuals who are not being directly targeted. An instance of the latter would be if the military disguised an IED or other booby trap as a child’s toy, and an innocent child then picked up the toy and got hurt as a result.

While some things like car bombs and IEDs are not considered to be perfidious, some argue that they should be because they are the very definition of perfidy: disguising something harmful to look harmless as a way to ambush the enemy. The key in avoiding perfidy is to be overtly military. This means that, even when setting a trap, the fact that the military set the trap must be unmistakable in order to avoid being guilty of perfidy.

Perfidy Example in a Libel Case

In 1928, a political candidate by the name of F.B. Streeter sued the publisher of Emmons County Farmers Press and its editor, George W. Lynn, over an article he claimed was published “maliciously” in the July, 1926 edition. Streeter alleged the article was defamatory to his reputation. Among other insulting and accusatory points, Streeter (referred to as “Frisky Buckles” in the article) was said to have been guilty of committing perfidy by tampering with election ballots. Specifically, the article stated:

“This act of perfidy on the part of Frisky Buckles, occurring at the primaries, is not so fatal to the Free Press as it would have been had it been pulled off in the fall, and we are glad he exposed this crookedness in the primary.”

The article concluded with the following call-to-action, which was directed at Streeter:

“Stand up, Mr. Buckles, and tell the people of this county how you deliberately, all by yourself, repealed the election laws of the state in so far as they applied to this county.”

The Press and Lyon both admitted to having published the article, and to having used the name “Frisky” to refer to Mr. Streeter. They denied any malice, and claimed that the complaints made in the article were expressions of opinion and criticism that were reasonable and fair, based on the facts that were listed in the article.

The Court noted that the testimony given showed that Streeter did, in fact, fail to handle the ballots as the law directed. Streeter testified that this was a mistake, and that he was ignorant of the exact provisions of the law. He further testified that he believed he was in full compliance with the law, and that he had not intended to take unfair advantage of anyone. Streeter admitted that he realized that what he had done was wrong only when he read the defamatory article.

Lynn testified that he wrote and published the article in good faith, believing the facts within it to be true, and that the comments he made were based on an investigation that he had personally conducted. However, there was evidence to show that Lynn and Streeter were not exactly friends, and the Court found that the article was indeed libelous. The Court further noted that the evidence failed to show that Streeter was the kind of person the article made him out to be.

The Court added that, while Lyon and Emmons County Farmers Press had every right to state the facts concerning the mistake, or failure to comply with the law regarding the ballots, they went too far when they added their own deductions and conclusions to the article that defamed Streeter. The Court deemed those comments to be libelous, and because they could not be proven to be true, they must be accepted as false by default.

The trial court, having already determined that the newspaper had printed a libelous article, instructed the jury to deliberate only on how much in monetary damages they would be awarding to Streeter. Lyon and Emmons County Farmers Press appealed, however the North Dakota Court affirmed the decision of the lower court.

Related Legal Terms and Issues

  • Crimes of War – Crimes committed against an enemy, prisoners of war, or others in wartime that violate international agreements or which are offenses against humanity.
  • Defamation – An intentional false statement that harms a person’s reputation, or which decreases the respect or regard in which a person is held.
  • Geneva Conventions – A set of treaties that defines the proper treatment of civilians, prisoners of war (POWs), and soldiers who are rendered unable to fight in combat.
  • Libel – Responsible by law; to be held legally answerable for an act or omission.
  • Monetary Damages – A court order awarding a specified amount of money to a person for damages suffered due to the acts of another.