The Practical Guide to Humanitarian Law

« Calling things by the wrong name adds to the affliction of the world. » Albert Camus.


The legal statute of mercenaries differs in international law and in humanitarian law, although international conventions use the same definition of mercenaries.

Under International Humanitarian Law

As defined by Article 47 of Additional Protocol I to the Geneva Conventions, a mercenary is any person who:

  1. is specially recruited locally or abroad,
  2. does, in fact, participate directly in the hostilities,
  3. is motivated to take part in the hostilities essentially by the desire for private gain and, in fact, is promised, by or on behalf of a party to the conflict, material compensation substantially in excess of that promised or paid to combatants of similar ranks and functions in the armed forces of that party
  4. is neither a national of a party to the conflict nor a resident of a territory controlled by a party to the conflict;
  5. is not a member of the armed forces of a party to the conflict; and
  6. has not been sent by a State that is not a party to the conflict on official duty as a member of its armed forces.

It must be noted that this definition is a very restrictive one since it applies only to international armed conflict and requires six cumulative criteria to be met. According to Article 47 of Additional Protocol I, the determination of mercenary status is to be done by a “competent tribunal” of the detaining power.

Under international humanitarian law, being a mercenary does not constitute a specific crime. The same holds true for the Statute of the International Criminal Court. If arrested, mercenaries are not entitled to the status of prisoners of war, but the detaining power can decide to treat them according to this status. They must always be treated humanely according to the fundamental guarantees of humanitarian law, as defined by Article 75 of API. They can be prosecuted for being a mercenary only under the national law of the detaining power if it contains such provisions designating mercenarism as a distinct crime.

It is clear that the category of “mercenary” cannot be extended to cover some grey area regarding voluntary combatants who do not share the nationality of the belligerents and decide to take part in a conflict, or employees of private military companies present in situations of conflict. The main rationale of this category is to impose the stigma of financial greed as opposed to the virtues of patriotism and honor that would characterize regular combatants. But apart from this, the mercenary category is of little use with regard to the necessary regulation of what private military companies’ employees are allowed to do in situations of conflict. Relying on individual determination of status after arrest and requesting the six criteria to be filled will only make the situation more incoherent among these employees without changing the status of the companies itself. Efficient regulation of private military employees should rather bring them back into IHL basic categories of civilians or combatants. The same is true for so-called irregular combatants and foreign combatants belonging to a State that is not party to a non-international or international conflict

CombatantsPrivate military companies

Under Public International Law

The definition and regulation of mercenarism is also provided by two specific mercenary international conventions. The first one is the International Convention against the Recruitment, Use, Financing, and Training of Mercenaries, which was adopted by the United Nations on 4 December 1989, pursuant to UNGA Resolution A/RES/44/34, and entered into force on 20 October 2001. As of June 2015, thirty-three States have ratified it. The second one is a regional one sponsored by the African Union, the Convention for the Elimination of Mercenarism in Africa, adopted in Libreville on 3 July 1977 and entered into force in April 1985. As of April 2013, it has thirty States Parties. The purpose of these conventions is not to regulate their behavior and status but to eliminate mercenaries through criminalizing them.

The two conventions refer to the same definition of mercenary as the one contained in international humanitarian law, but they enlarge the scope of the definition. Indeed, the conventions are applicable in situations of international and non-international armed conflicts, while the IHL definition is limited to international armed conflicts.

Under the two mercenary Conventions, mercenarism is considered a crime, whereas under international humanitarian law, being a mercenary is not per se a violation of the Geneva Conventions or Protocols.

Under Customary International Humanitarian Law

Rule 108 of the 2005 ICRC customary IHL study prescribes that in the context of an international armed conflict, mercenaries, as defined in Additional Protocol I, do not have the right to combatant or prisoner-of-war status and may not be convicted or sentenced without previous trial.

Mercenaries are not entitled to the status of combatant, prisoner of war (API Article 47), or any of the categories of protected persons provided for by the Geneva Conventions, unless they are wounded or sick, although they must always benefit from humane treatment. In conformity with the Geneva Conventions, they can be held criminally responsible if they commit war crimes or other grave breaches of humanitarian law. They are entitled to the fundamental guarantees established for all individuals.

CombatantsFundamental guaranteesNon-state armed groupsPrisoners of warPrivate military companiesSituations and persons not expressly coveredWounded and sick persons

For Additional Information: Cameron, Lindsey. “Private Military Companies: Their Status under International Humanitarian Law and Its Impact on Their Regulation.” International Review of the Red Cross 863 (September 2006): 573–98.

Dinstein, Yoram. The Conduct of Hostilities under the Law of International Armed Conflict . Cambridge: Cambridge University Press, 2004, esp. chap. 2.

Goldstein, Bohunka O. “Mercenaries.” In International Criminal Law , edited by M. Cherif Bassiouni, 439–58. Ardsley, NY: Transnational, 1999.

Green, L. C. “The Status of Mercenaries in International Laws.” Israel Yearbook on Human Rights 8 (1978): 9–62.

Yusuf, A. A. “Mercenaries in the Law of Armed Conflicts.” In The New Humanitarian Law of Armed Conflict , edited by A. Cassese, 1:113–27. Naples: Editoriale Scientifica, 1979.

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