In warfare, a reprisal is a limited and deliberate violation of the laws of war to punish an enemy for breaking the laws of war. A legally executed reprisal is not an atrocity.

To be legally justified, a reprisal can only be directed against the party carrying out the original violation, can only be carried out as a last resort, after having given formal notice of the planned reprisal, must be proportionate to the original violation, must have the aim of pursuading the original violator to comply with the legally accepted behaviour in future, and must not continue after the illegal behaviour ends.

Circumstances usually dictate that reprisals can only be taken against people innocent of the original violation, which increases the probability that the reprisals will themselves be viewed as hostile acts, risking a vicious circle of violations by both sides.

All four Geneva Conventions prohibit reprisals against, respectively, battlefield casualties, shipwreck survivors, prisoners of war and civilians, as well as certain buildings and property. An additional 1977 protocol extends this to cover historic monuments, works of art and places of worship. Despite this, in ratifying the Conventions, a number of states have reserved the right to undertake reprisals against civilians, including the United Kingdom and Germany.

In the United States military, the lowest ranked commander who can authorize a reprisal is the general in command of the theater (i.e. Europe, Middle East, etc).

See also

• The related concept of Letter of marque (license to hunt enemy ships and retake lost ships from the enemy).
• War
  • Laws of war