Ruse of war

A ruse of war, or ruse de guerre, is an action taken by a belligerent in warfare to fool the enemy in order to gain intelligence or a military advantage against the enemy.

Ancient history

 * Prior to a naval battle with King Eumenes II of Pergamon, Hannibal sent a herald with a message for the opposing commander. This was a trick to locate Eumenes' ship, so that Hannibal could concentrate his forces against it.
 * Alexander the Great walked his men up and down the river continuously to condition and fool his opponents into believing he was leaving the majority of his men behind. One night Alexander marched a contingent of his men up river and crossed the Indus and fought and won a battle against a local ruler Porus in the Battle of Hydaspes in 326 BC.

Modern history

 * During the American Civil War, Union General George Meade's General Order No. 13 of 1865 was retracted after it was determined that his criticism of Brigadier-General McLaughlin was based on "nothing more than the obvious result of those ruses de guerre, by which the very best officers may, at times, be victimized", after the Confederate Army falsely claimed that it had gained a foothold in the Union Army lines.


 * An effort by the Japanese Navy to lure the Russian fleet out of its harbor during the Russo-Japanese War in 1904 was described by The New York Times as "a clever ruse of war to entice the Russian ships out of Port Arthur".


 * The use of the American flag flown on the RMS Lusitania while crossing through the Irish Sea to avoid attack by German submarines during the First World War was criticized in debate in the United States House of Representatives by Republican Eben Martin of South Dakota, who stated that "the United States cannot be made a party to a ruse of war where the national colors are involved".


 * During the Second Sino-Japanese War, the former IJN battleship Asahi, which had been taken out of reserve shortly after the outbreak of war for use as a troop transport but then converted to a repair ship, was fitted with dummy wooden main batteries fore and aft to resemble an old battleship after her arrival in Shanghai on 29 December 1938.


 * In the lead up to the First Battle of Sirte during the Second World War, the Fast Minelayer HMS Abdiel successfully impersonated a force of two battleships using false signals traffic, as part of a decoy mission against Italian forces.


 * The Allied Combined Operations raid on the Normandie Dock in Saint Nazaire employed several legitimate ruses during their voyage up the Loire estuary, including flying German colours and replying to signal challenges by giving misleading replies in German. These measures were all designed to buy time for the attacking force. When these tactics ceased to be effective and German shore batteries opened fire in earnest, all the British ships lowered their German colours and hoisted White Ensigns before returning fire.


 * Wehrmacht Field Marshal Erwin Rommel's withdrawal of his Afrika Korps at the Second Battle of El Alamein in November 1942 was described to the German people as a ruse de guerre and not as a retreat.


 * German commando Otto Skorzeny led his troops wearing American uniforms to infiltrate American lines in Operation Greif during the Battle of the Bulge. Skorzeny later reported that he was told by experts in military law that wearing American uniforms was a defensible ruse de guerre, provided his troops took off their American uniforms, and put on German uniforms, prior to firing their weapons. Skorzeny was acquitted by a United States military court in Dachau in 1947, after his defense counsel argued that the "wearing of American uniforms was a legitimate ruse of war for espionage and sabotage" as described by The New York Times.

Mythology

 * During the Trojan War, the Greeks pretend to give up their fruitless ten-year siege of the city of Troy and sail away, leaving behind the Trojan Horse. After the Trojans pull what they believed is a parting gift within the walls of the city, soldiers hidden within exit at night and open the gates.

Fiction

 * In the novel A Ship of the Line, British Captain Horatio Hornblower sails his Dutch-built ship unmolested into a well-defended enemy harbor by flying French colors and hoisting the French recognition signal for the day.

Good faith
Good faith in dealing with the enemy must be observed as a rule of conduct, but this does not prevent measures such as using spies and secret agents, encouraging defection or insurrection among the enemy civilian population, corrupting enemy civilians or soldiers by bribes, or inducing the enemy's soldiers to desert, surrender, or rebel. In general, a belligerent may resort to those measures for mystifying or misleading the enemy against which the enemy ought to take measures to protect itself.

Legitimate ruses
Legitimate ruses include:
 * surprises, ambushes, feigning attacks, retreats, or flights;
 * simulating quiet and inactivity (to lull the enemy into complacency);
 * use of small forces to simulate large units (for example, inducing an enemy unit to surrender by pretending that it is surrounded by a large force);
 * transmitting false or misleading radio or telephone messages;
 * deception of the enemy by bogus orders purporting to have been issued by the enemy commander;
 * making use of the enemy’s signals and passwords or secret handshakes;
 * pretending to communicate with nonexistent troops or reinforcements;
 * deceptive supply movements (which might make the enemy think you are preparing for action when you're not);
 * deliberate planting of false information;
 * use of spies and secret agents;
 * moving landmarks (to confuse the enemy operating in unfamiliar territory);
 * putting up dummy guns and vehicles or laying dummy mines;
 * erection of dummy installations and airfields (to intimidate or encourage useless attack);
 * removing unit identifications (but not those that identify the belligerent while in combat) from uniforms;
 * psychological warfare activities;
 * disguising a warship to appear to be a neutral merchant vessel, or a merchant vessel on your opponent's side, has traditionally been considered a legitimate ruse de guerre, provided the belligerent raises their own flag to break the deception, prior to firing their guns. This was called sailing under false colors. Both sides during the world wars used this tactic, most famously the Royal Navy's Q ships.
 * disguising a warship to appear to be one of your opponent's warships has traditionally been considered to be a legitimate ruse de guerre, provided the belligerent raises their own flag to drop the disguise, prior to firing their guns. The Germans took steps to disguise their pocket battleships as Allied cruisers during World War II. This tactic was also used by the Royal Navy to great effect during the Napoleonic Wars, since the boarding and capture of enemy vessels was quite common during that time, and information about the current ownership of vessels was not easy to disseminate rapidly.

No treachery or perfidy
Ruses of war are legitimate so long as they do not involve treachery or perfidy on the part of the belligerent resorting to them. They are, however, forbidden if they contravene any generally accepted rule.

When landmines were not marked or reported, or when they are disguised, they are perfidious per the Geneva Conventions, annex 10 October 1980:
 * traps that are apparently harmless portable objects, that contain an explosive charge, and are specifically designed to produce a detonation when you move or approach it;
 * traps that are attached or associated in any way with:
 * emblems, signs, or signals internationally recognized;
 * sick, wounded, or dead;
 * burial, cremation, or graves;
 * facilities, equipment, supplies, or medical transportation;
 * toys for children or other portable objects;
 * food or drink;
 * kitchen utensils or appliances;
 * objects of a religious nature;
 * historic monuments, works of art, or places of worship which constitute a cultural or spiritual heritage of people.

Prohibited ruses
Article 23 of the 1907 Hague Convention IV - The Laws and Customs of War on Land provides that: "It is especially forbidden....(b) To kill or wound treacherously individuals belonging to the hostile nation or army....(f) To make improper use of a flag of truce, of the national flag, or of the military insignia and military uniform of the enemy, as well as the distinctive badges of the Geneva Convention". Protocol I of the Geneva Conventions expanded the rules of prohibiting certain type of ruses as defined in Articles 37, 38, and 39.

The line of demarcation between legitimate ruses and forbidden acts of perfidy is sometimes indistinct. In general, it would be an improper practice to secure an advantage over the enemy by deliberate lying or misleading conduct which involves a breach of faith, or when there is a moral obligation to speak the truth. For example, it is improper to pretend to surrender to secure an advantage over the opposing belligerent, such as the Union troops did during the Siege of Port Hudson during the American Civil War to cover a retreat.

To broadcast to the enemy that an armistice had been agreed upon when such is not the case would be treacherous. Abuse of the protections afforded to medical personnel (by disguising combat soldiers as medics, or by putting a red cross on a combat vehicle) is also considered unacceptable. In 1946, a German soldier, Heinz Hagendorf, was found guilty by a U.S. military tribunal at the Dachau Trials and sentenced to six months imprisonment for having “wrongfully used the Red Cross emblem in a combat zone by firing a weapon at American soldiers from an enemy ambulance displaying such emblem."

Books

 * Stratagems (Latin: Strategemata), by the 1st-century Roman author Frontinus, which concerns military stratagems drawn from Greek and Roman history.
 * Stratagems (Greek: Στρατηγηματα), book by the 2nd-century Macedonian author Polyaenus which concerns military strategems. In common with Frontinus' work (see above), the title is sometimes given as Strategemata.
 * Stratagems of the Warring States, English title of a Chinese book compiled between the 3rd to 1st centuries BCE. Alternative English titles include Strategies of the Warring States.
 * Thirty-Six Stratagems, English title of a Chinese book concerning stratagems which have military and civil applications.