Military deception refers to attempts to mislead enemy forces during warfare. This is usually achieved by creating or amplifying an artificial fog of war via psychological operations, information warfare, visual deception and other methods. As a form of strategic use of information (disinformation), it overlaps with psychological warfare. To the degree that any enemy that falls for the deception will lose confidence when it is revealed, he may hesitate when confronted with the truth.
Deception in warfare dates back to early history. The Art of War, an ancient Chinese military treatise, puts great emphasis on the tactic. In modern times military deception has developed as a fully fledged doctrine. Misinformation and visual deception were employed during World War I and came into even greater prominence during World War II. In the buildup to the 1944 invasion of Normandy the Allies executed one of the largest deceptions in military history, Operation Bodyguard, helping them achieve full tactical surprise.
Broadly, military deception may take both strategic and tactical forms. Deception across a strategic battlefield was uncommon until the modern age (particularly in the world wars of the 20th century), but tactical deception (on individual battlefields) dates back to early history. In a practical sense military deception employs visual misdirection, misinformation (for example, via double agents) and psychology to make the enemy believe something that is untrue. The use of military camouflage, especially on a large scale, is a form of deception. The Russian loanword maskirovka (literally: masking) is used to describe the Soviet Union and Russia's military doctrine of surprise through deception, in which camouflage plays a significant role.