Reprisal (International Law) (Ro: Represalii, Fr: Représailles, Gr: αντίποινα) (See also: Countermeasures, Retorsion) = an act committed by a State in response to an earlier violation of international law from an adversary. Reprisals are acts that would otherwise be considered illegal but under strict conditions are lawful. They can be belligerant or non-forcible, the latter usually refered to as 'countermeasures'. 

In order for such a measure to be considered legal, there must be a previous wrongful act committed by the other party, the measure must be preceded by an unsatisfied request for redress and remain proportional to the earlier violation. In addition, for belligerant reprisals, a warrning must be given beforehand, the decision to carry out reprisals must be taken by a competent authority and a termination of the reprisal must come into place as soon as the other party’s violation stops.

Useful links

Legislation - Lieber Code of 1863, Article 28 [English] - The Fourth Geneva Convention of 1949, Article 33 [English] - Commentary of 1958 to article 33 of the Fourth Geneva Convention [English] - Vienna Convention on the Law of Treaties 1969, Article 60(5) [English] - UN General Assembly Resolution on Basic Principles for the Protection of Civilian Populations in Armed Conflicts adopted in 1970 - Articles on Responsibility of States or Internationally Wrongful Acts 2001, Articles 51, 52 [English]

Case Law - Execution of German-Portuguese Arbitral Award of 30 June 1930 [English, French] - Air Service Agreement between the United States of America and France, Arbitral Tribunal Award of 27 March 1946 [English, French] - Gabčíkovo-Nagymaros Project, Hungary v. Slovakia, International Court of Justice Judgement of 1997 [English, French]

Online publications - Akande D. & Cawthorne L.H., 2015, Lieber Series: The Lieber Code and the Regulation of Civil War in International Law, Columbia Journal of Transnational Law, Vol. 53, No. 3 [English] - Free Legal Encyclopedia - Reprisal [English]  - Sicilianos L.A, 1993, The Relationship Between Reprisals and Denunciation or Suspension of a Treaty, European Journal of International Law, Vol. 4, No. 3 [English]


Constantin V., 2010, Drept Internaţional, Bucureşti, Ed. Universul Juridic [Romanian]

Dinstein Y., 2004, The Conduct of Hostilities under the Law of International Armed Conflict, Cambridge University Press [English]

Klabbers J., 2013, International Law, New York, Cambridge University Press [English]


By Daniela Toma