Is there a place for mercenaries in the future of war?

They have been active in Ukraine since the 2014 annexation of Crimea, and in Syria as early as 2013 (in the form of predecessor, the Slavonic Corps). They have significant presence in countries including the Central African Republic, Libya and Mali. But it is their involvement in the invasion of Ukraine since early 2022 that has pushed the Wagner Group into headlines across the globe. Now, especially after the abortive mutiny in late June, everyone knows who they are.

However, Wagner Group, though perhaps especially brutal, and especially shadowy, is far from unique. From Aegis to G4S to Blackwater (now Academi), recent conflicts have seen an increasing number private contractors take on logistics, training and even security and combat roles. (Though in the case of Wagner, it’s somewhat questionable how “private” they really were). It’s the latter, often called mercenaries, which are particularly controversial. But what are mercenaries, and how worried should we be about their proliferation?

What are mercenaries?

The first thing is to consider the difference between private military and security companies (PMSCs) and mercenaries. PMSCs can provide a range of services, including maintenance, security, training, and so on. Mercenaries both in common usage, and from the perspective of international law, specifically refer to private agents who are recruited to fight in an armed conflict. Thus, not all PMSCs do necessarily provide mercenaries – though the line is incredibly blurry.

A commonly used legal definition can be found in the 1977 First Additional Protocol to the Geneva Conventions. In order to count as a mercenary, someone must:

1. be specially recruited locally or abroad in order to fight in an armed conflict;
2. take a direct part in the hostilities;
3. be motivated to take part in the hostilities essentially by the desire for private gain and to be 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. not be a national of a Party to the conflict or a resident of territory controlled by a Party to the conflict;
5. not be a member of the armed forces of a Party to the conflict; and
6. not have been sent by a State which is not a Party to the conflict on official duty as a member of its armed forces.

This is a fairly narrow definition. For example, it suggests that a Russian Wagner Group employee doesn’t count as a mercenary when fighting in Ukraine – because they are a national of a party to the conflict. Yet while Wagner in Ukraine has reportedly been relying mostly on Russian prisoners, they’ve previously been reported to have recruited from countries including Serbia, Belarus, Uzbekistan, Moldova and even France. Unlike their Russian colleagues, any Wagner employees from these countries could be considered mercenaries.

The “motivation” requirement may also be tricky. Many who join groups such as Wagner are undoubtedly motivated by financial gain. Yet other factors can also play a role, including a belief in Putin’s “Russian World” ideal and Russian nationalism, or simply the desire to shorten a prison sentence.

What’s the problem with mercenaries?

It shouldn’t be surprising that mercenaries pose a challenge to the typical just war theory approach to the ethics of war. Just war theory, after all, relies on the crucial distinction between combatants and non-combatants. Combatants are authorized by their state to kill on its behalf, yet mercenaries are simply acting on their own private interests.

More practically – though certainly raising important moral issues as well – the use of mercenaries is often associated with human rights violations. Indeed, we may fairly hypothesize that certain states favour the use of mercenaries precisely because they can distance themselves more easily should human rights violations or war crimes occur. Mercenaries and PMSCs more generally also allow states, like Russia, to project power abroad (and potentially destabilize areas) without having to officially commit ground forces. They are, in Putin’s own words, “an instrument in the pursuit of national interests without the direct participation of the state”. Moreover, the widespread use of mercenaries is considered by some to pose a threat to the (post-) Westphalian state system. They undermine the state’s monopoly on the use of force, and may herald – or speed up the development of – what Hedley Bull referred to as a “neo-mediaeval” world order.

But mercenaries seem here to stay, if they were ever really gone. This raises the crucial question – can we imagine a just, or at least permissible, war that includes mercenaries?

The answer, tentatively, might be yes. Many objections to mercenarism are contingent, and as Sean McFate points out, some objections to mercenaries may be due to ignorance or stigma. For example, it’s not as if being employed by a state has historically prevented soldiers from committing serious war crimes and human rights violations.

While a well-organised all-volunteer force is absolutely preferable to a mercenary army, a mercenary army may be preferable to an army made up of conscripts.  

Furthermore, James Pattison has argued for an approach he calls the Cumulative Legitimacy Approach, according to which the legitimacy of a military is both scalar and cumulative. It considers factors including the effectiveness of a military, the degree to which there is democratic control over the use of military force, the treatment of military personnel and the effect a military has on communal bonds. One upshot of this approach is that mercenary armies may be considered at least somewhat legitimate, depending on their ability to meet the criteria set out by Pattison. In particular, he suggests that armies made up primarily of conscripts are less likely to meet this standard than PMSCs. Thus, while a well-organised all-volunteer force is absolutely preferable to a mercenary army, a mercenary army may be preferable to an army made up of conscripts.  

Is there a future for mercenarism?

It is at least conceptually possible that a PMSC or mercenary army can meet the requirements set out by Pattison. His more nuanced approach – or one similar to it – is valuable because it follows that there may be circumstances in which a state can legitimately use mercenaries. This seems especially important for states who lack an effective military, either due to lack of experience or exhaustion from prolonged conflict. For example, Nigeria hired South African mercenaries to help fight Boko Haram in 2014. Though use of mercenaries is outlawed under the African Union’s Convention for the Elimination of Mercenarism in Africa, in this case they may have helped turn the tide against Boko Haram.

While a single example should by no means be taken to be representative of mercenaries and their effectiveness, it does suggest it’s not just theoretically possible that mercenaries can be an effective supplement to traditional state military force. Perhaps, with the private military genie apparently firmly out of the bottle, the right question no longer is “how can we ban mercenaries?”, but “how can we effectively regulate PMSCs and mercenaries to prevent the worst?”.

Revisiting the concept of mercenarism in IHL would be an important first step. But regardless of whether we choose to pursue a more effective ban, or more effective regulation, it would require a serious and global political commitment. The Wagner Group’s well-publicized crimes in Ukraine have generated media attention and outrage, but could it spur some much-needed international action?