A mercenary (, MUR-sə-nerr-ee) is a private individual who joins an armed conflict for personal profit, is otherwise an outsider to the conflict, and is not a member of any other official military. Mercenaries fight for money or other forms of payment rather than for political interests.
Beginning in the 20th century, mercenaries have increasingly come to be seen as less entitled to protection by rules of war than non-mercenaries. The Geneva Conventions declare that mercenaries are not recognized as legitimate combatants and do not have to be granted the same legal protections as captured service personnel of the armed forces. In practice, whether or not a person is a mercenary may be a matter of degree, as financial and political interests may overlap.
International and national laws of war
Protocol Additional GC 1977 (APGC77) is a 1977 amendment protocol to the Geneva Conventions. Article 47 of the protocol provides the most widely accepted international definition of a mercenary, though it is not endorsed by some countries, including the United States. The Protocol Additional to the Geneva Conventions of 12 August 1949, and relating to the Protection of Victims of International Armed Conflicts (Protocol I), 8 June 1977 states:
All the criteria, as listed in 2(a) through 2(f), must be met, according to the Geneva Convention, for a combatant to be considered a mercenary. While mercenaries do not enjoy the same protection as prisoners of war do, they must still be treated humanely according to the rules of the Protocol and they may not be punished without a trial.
On 4 December 1989, the United Nations passed resolution 44/34, the International Convention against the Recruitment, Use, Financing and Training of Mercenaries. It entered into force on 20 October 2001 and is usually known as the UN Mercenary Convention. Article 1 of the UN Mercenary Convention contains the definition of a mercenary. Article 1.1 is similar to Article 47 of Protocol I. Article 1.2 broadens the definition to include a non-national recruited to overthrow a "Government or otherwise undermin[e] the constitutional order of a State; or Undermin[e] the territorial integrity of a State"; and "Is motivated to take part therein essentially by the desire for significant private gain and is prompted by the promise or payment of material compensation". Under Article 1.2, a person does not have to take a direct part in the hostilities in a planned coup d'état to be a mercenary.
If a person is proven to have worked as a mercenary for any other country while retaining Austrian citizenship, their Austrian citizenship will be revoked.
In 2003, France criminalized mercenary activities, as defined by the protocol to the Geneva convention for French citizens, permanent residents, and legal entities (Penal Code, L436-1, L436-2, L436-3, L436-4, L436-5). This law does not prevent French citizens from serving as volunteers in foreign forces. The law applies to military activities with a specifically mercenary motive or with a mercenary level of remuneration. However, due to jurisdictional loopholes several French companies provide mercenary services.
The French state owns 50% of Défense Conseil International, which it founded, a private military company (PMC) which does not supply any fighters but is used to export military training services. It realised a profit of €222 million in 2019.
It is an offence "to recruit" German citizens "for military duty in a military or military-like facility in support of a foreign power" (§109h StGB). Furthermore, a German citizen who enlists in the armed forces of a state they are also a citizen of risks the loss of their citizenship
In 1998, South Africa passed the Foreign Military Assistance Act that banned citizens and residents from any involvement in foreign wars, except for humanitarian operations, unless a government committee approved deployment. In 2005, the legislation was reviewed by the government because:
South African citizens were working as security guards in Iraq during the American occupation of Iraq;
consequences of the mercenary soldier sponsorship case against Mark Thatcher for the "possible funding and logistical assistance in relation to an alleged attempted coup in Equatorial Guinea" organized by Simon Mann.
As of 2010, South Africa forbids citizens from fighting in foreign wars unless they are under the direct control of their own national armed forces.
In the United Kingdom, the Foreign Enlistment Act 1819 and the Foreign Enlistment Act 1870 make it unlawful for British subjects to join the armed forces of any state warring with another state at peace with Britain. During the Greek War of Independence, British volunteers fought with the Greek rebels, which could have been unlawful per the Foreign Enlistment Act. It was unclear whether or not the Greek rebels constituted a 'state', but the law was later clarified to indicate that they were.
The British government considered using the Act against British subjects fighting for the International Brigades in the Spanish Civil War and the FNLA in the Angolan Civil War, but on both occasions chose not to do so.
Civilians with the US Armed Forces lose their law of war protection from direct attack if, and for such time as, they directly participate in hostilities.
The Anti-Pinkerton Act of 1893 (5 U.S.C. § 3108) forbids the US government from using Pinkerton National Detective Agency employees or similar private police companies.