Privatizing War

The modern state has a monopoly on the use of force. Nevertheless, private actors have been increasingly deployed in armed conflicts since the 1990s. How can this be? And what does international law say about it? Hendrik Simon discusses this with Sarah Katharina Stein, author of Der privatisierte Krieg (Mohr Siebeck 2024). 

Dear Katharina, you begin your book with a quote from Erik Prince, founder and former CEO of the private military company Blackwater, who argued that “[g]overnments do not have a monopoly on innovation and tactical application in the next-phase generation of warfare.” Is Prince right? Are we facing a new phase of private violence in international law?

And the quote ends with: “You can send 100,000 conventional soldiers, or you can send 3,000–4,000 contractors […] to sort this out. Which one would [the genius] have gone for?” I wasn’t especially keen on starting the book with a quote by him, but it just captures the prevailing sentiment towards PMCs at the moment – they seem to be a smartass choice. Of course, I think otherwise and hope to have proven it in my book.

Are we facing a new phase of private violence in international law? I think so, yes. This did not happen overnight, but developments in this direction have become more pronounced in recent years and will continue to accelerate.

I think in this quote, Erik Prince understands and plays with the particularities of violence in international law. We can theorize and “legalize” violence via the state monopoly on the use of force, sovereignty and the rules of jus ad bellum and jus in bello. However, even under the most perfect system, one cannot eradicate violence. Violence, as physical coercion, does not cease to exist because of state-made laws. Or to put it differently: potestas does not end vis. This entails the gist of Prince’s statement: the state monopoly on the use of force does not include a monopoly in technical innovations. Drone warfare is a prime example: drones were developed mostly by private actors. You can now privately download construction manuals for 3D-printers and it is said that the continuous outsourcing of know-how by the U.S. government led to the lack of core competences in drone warfare, so now they have to employ private contractors to be fully operational. Oftentimes, states make themselves dependant on private contractors when they rely on new, privately developed innovations.

This illustrates a further point: violence and war are a market. States operate under austerity rules and want to save money; hence they tone down development, training and cooperation. Buying fighters for particular needs like a set mission or a specific conflict might save money in the moment. No soldiers need to be trained, no gear to be developed and medical bills and pensions are not paid. Looking with a very neoliberal lens, war by contract seems to be cheaper than maintaining standing armies. Meanwhile, private actors can sell their services wherever needed or where the most money is to be gained.

Is this a new process?

This is not new, but newer developments speed up this process. The security architecture has changed in recent years, e.g. with the rise of authoritarianism. States are turning inward, meaning that national particularities are driving and justifying forces on the international stage. Look at Syria or Ukraine – very few international actors argue primarily with the need of people affected by war and dictatorship. Most care about migrants, internal security and the spread of war reaching them. Authoritarian figures also place less emphasis on due process, the rule of law and transparency. All this can be circumvented if PMCs are employed instead of the military, because constitutional path dependencies for deployment are only applicable to the military.

In the early modern period, it was common practice to employ private actors of violence: mercenary armies, for example, in the context of the Thirty Years’ War, or trading companies in the context of colonialism. With the emergence of the state’s monopoly on the use of force, however, violence is actually tied to the state. The entire history of international law is, if you will, a fetishization of the state. At the same time, you note that the number of missions carried out by private military and security companies has risen sharply since the 1990s. How can this be?

Yes, that seems a paradox. What it reveals is that states did not consciously decide to abandon their monopoly on force. Rather, they sleepwalked into it, driven by ideology and economic expediency

The pragmatic driver here is economic. After the Cold War, military budgets collapsed everywhere. And, neoliberal thinking was ascendant. The U.S. had a third fewer soldiers, Britain’s armed forces shrank to Waterloo-era levels. Meanwhile, you had a proliferation of new conflicts like civil wars, asymmetric threats and failed states. That could not be ignored. States faced a resource crisis: they could not maintain the personnel deployments needed for all these simultaneous conflicts. Rather than making difficult strategic choices about which conflicts to engage in, states opted for privatization because PMCs offered a solution. They are flexible, deployable at short notice, and they do not deplete your standing military.

At the same time, the end of the Cold War and its aftermath resulted in a flood of soldiers, equipment and ammunition onto the market. Personnel and weapons were available at low cost, which resulted in the establishment of numerous new PMCs during this period. Timing was just favorable.

 “The dichotomy of international treaty law is strict: there are no quasi-combatants or semi-civilians,” as you write (p. 84). What are private military companies (PMCs) actually, in terms of international law?

There is no group status in international law, hence we have to look at the individuals concerned. Private military contractors are virtually never members of the armed forces, because states lose all the advantages of their employment if they formally incorporate them into their military.

In some circumstances, they could be members of other militias belonging to a Party to the conflict, as stated in Art. 4(A) §2 GC III. They would have to carry arms openly and wear a distinctive sign (lit. b) and c)), which can be achieved easily. However, in my research I found that most PMCs lack responsible command as per lit. a) and d). While the Geneva Conventions do not concretize the threshold for a responsible command, it is clear that the hierarchy, structure of obedience, penalties and punishment must be comparable to those of the armed forces to gain the same privileges under humanitarian law. As some PMCs might have those structures, most do not. One can even ask if civil rules and regulations, such as stemming from contract and labor law, can ever be on par with military command and obedience. Hence most PMCs are not combatants.

Contrary to popular belief, PMCs do not constitute mercenaries in the legal sense, a distinction that owes less to the nature of PMCs themselves than to the restrictiveness of the mercenary definition in Article 47 AP I. I confess this is something of a pet peeve: my growing collection of headlines conflating PMCs with mercenaries reflects a persistent misunderstanding rooted not in the realities of private military contracting, but in the definitional architecture of IHL itself – and of course, the stigma associated with mercenaries is used by newspapers to make a point. The mercenary definition is so restrictive that it is unlikely that anyone will meet all six requirements. Particularly problematic are the conditions that refer to belonging to a state party, such as residence in the territory or nationality of a party to the conflict, or deployment. However, the most problematic criterion is that one can only be considered a mercenary if one is motivated to take part in the hostilities essentially by the desire for private gain. This is such a vague and malleable criterion, full of value judgements reminiscent of the jus ad bellum realm, that there is a saying: “any mercenary who cannot exclude himself from this definition deserves to be shot – and his lawyer with him.”

This leaves us with the category of civilians. However, if PMCs take part in hostilities, they are losing their protection under IHL and are subsequently legitimate targets of attacks. The exact boundaries of participation, and thus the point at which protection ends, are controversial. In the context of the discussion about unlawful combatants, representatives of this category argue that adopting a combat-ready stance should constitute active participation, meaning that non-state actors are legitimate targets for countermeasures at all times. This is reflected in the treatment of so-called terrorists. However, PMCs are not yet viewed in this way, mainly because states that support the category of unlawful combatants benefit from PMCs and are, as of now, less likely to oppose them on the battlefield.

All in all, PMCs are not really fitting into the tight categories of IHL.

Although the state has a monopoly on the use of force, international law has enormous problems dealing with private actors of violence. Why is that? What approaches exist in international law?

International law struggles with private actors of violence because its core architecture is state-centric: violence and power are assumed to be exercised by states, not by diffuse constellations of groups, companies, militias, fighters or security contractors. This state-centric architecture also leads to the fact that there is not much to be gained from non-state groups, when they adhere to state-centric laws – they can never reach an equal position or corresponding bargaining power. Thus, addressing non-state actors inevitably includes elements of hierarchy. Against this background, power can be gained by sheer force, not at the state-level bargaining table, because there is (generally speaking) not a place open.

Art. 4(A) § 2 partially integrates certain non-state actors into the law of armed conflict, but excludes many groups operating transnationally or failing to meet organizational thresholds. State responsibility doctrine addresses non-state actors indirectly by the possibility of attributing their conduct to states, thus holding states accountable for supporting, directing, or failing to prevent non-state violence. Counter-terrorism regimes, by contrast, treat designated non-state actors as criminal organizations outside the framework of armed conflict, denying them combatant status while subjecting them to Security Council sanctions, asset freezes, and travel bans under Chapter VII measures.​

International criminal law seeks direct individual accountability by prosecuting members of armed groups for war crimes before international tribunals, though this faces jurisdictional and enforcement challenges. Human rights law imposes positive obligations on states to protect individuals from violence by non-state actors through due diligence standards, requiring prevention, investigation, and punishment, though it struggles to directly bind non-state groups themselves. Finally, soft-law initiatives like the Montreux Document and various codes of conduct attempt to regulate private military and security companies through voluntary standards, transparency mechanisms, and corporate accountability frameworks, which lack binding enforcement. Thus, PMCs fall into a structural blind spot, operating in spaces where state control is weak or unwanted, across borders, and through contractual relations that make attribution and enforcement difficult.​

​This fragmentation reflects geopolitical hierarchies: Western-aligned groups, like most PMCs, gain operationality while liberation movements are criminalized, and international law’s regulatory gaps enable powerful states to instrumentalize non-state violence while criminalizing resistance in the Global South.

Legitimacy is of central importance for the use of force. What legitimacy deficits exist in PMCs?

PMCs face fundamental legitimacy deficits stemming from their hybrid status as private entities performing sovereign functions. First, they lack democratic accountability: operating outside traditional chains of command and parliamentary oversight, they are bound by contracts rather than public law obligations, creating perverse incentives where profit may conflict with conflict resolution. Second, states deliberately create legal accountability gaps around them and the companies offer services geared towards this: operating in jurisdictional grey zones with weak oversight, PMC personnel frequently evade sanction for abuses in ways that state armed forces cannot, corroding the rule of law and the normative framework of international humanitarian law. Finally, they suffer from a normative legitimacy deficit: by outsourcing violence to private actors, states undermine the conceptual basis of sovereignty itself: the monopoly on legitimate use of force that has structured international order since Westphalia. And, from TWAIL perspectives, the use of PMCs reproduces colonial patterns of outsourced coercion that obscure state responsibility while disproportionately affecting the Global South.​

You write that “the erosion of democratic principles through the relinquishment of the monopoly on the use of force must be countered by nation states – alone or together – by rethinking the role of private actors in international armed conflict” (p. 434). How could these deficits be addressed?

A first step must be awareness and acknowledgment. While some prominent cases of PMC-involvement were discussed in media and politics – like torture at Abu Ghraib, Blackwater and more recently the Wagner Group –, the structural problem of outsourcing sovereignty is ignored. Critical awareness of military outsourcing must be taken into account in debates about the German Armed Forces and compulsory military service, the EU and NATO. This is not to replace the Armed Forces, but to inform strategic decisions about troop composition in view of a privatised international environment. How do the (German) armed forces intend to deal with enemy combatants who are not regular soldiers? How will they cooperate with private companies on international missions? Who does Germany intend to hold accountable for Wagner’s human rights violations? What role can, will and should Germany and the EU play in international discourse within the framework of value-based foreign policy?

Furthermore, national and international initiatives to regulate the industry must be supported and self-regulatory regimes must be viewed very cautiously. Clearly, non-binding self-regulation that does not create new obligations is not an effective means of controlling state-like military power. The mere existence of self-regulation perpetuates its defensive effect against state regulation. The more influential entities that support such initiatives, the more this effect is reinforced. Above all, the voluntary commitment of a few companies has no effect on the industry as a whole. Companies that do not seek certification because a trustworthy reputation does not align with their business model are not influenced by the voluntary commitments of others. Unlike real law, self-regulation cannot reach those who are unwilling to comply. Therefore, by its very nature, self-regulation cannot regulate what is at risk: the erosion of the monopoly on the use of force and involvement in conflicts without accountability. That means, quite counterintuitively, that the promotion of self-regulatory instruments as the Montreux Document by states such as Germany, as well as by organizations such as the OSCE, NATO and the EU, is not a step in the right direction, but a major step away from the regulatory goal.

A minimum consensus I would like to see is a clear prohibition on outsourcing inherently sovereign functions, coupled with robust accountability mechanisms. If states were systematically held responsible for human rights and IHL violations committed by the PMCs they deploy, many of the perceived advantages of relying on such companies would quickly erode and the appeal of this rogue industry would likely diminish.

Ultimately, however, the repeated failure of international initiatives to establish genuine regulation of PMCs also lays bare the broader crisis of contemporary multilateralism and is not solely linked to the topic of international armed conflict.

You argue that for the first time since the emergence of PMCs after the Cold War, Western states are confronted with PMCs that are not deployed by them, but on the contrary are fighting on behalf of Russia (e.g. Wagner) against them or their allies. This is accompanied, you write, by an unprecedented interpretative clarity in the assessment of PMCs: “there is currently no moral room for interpretation – PMCs are on the wrong side.” (p. 416) Meanwhile, in Gaza, the Gaza Humanitarian Foundation, a questionable organization of former soldiers, has been deployed to distribute food, which has also led to regular armed violence. Critics speak of a militarized aid program. Has the momentum of clarity regarding PMCs already passed?

Yeah, I might have been too hopeful. Clarity about PMCs was never going to last very long, because it was born out of this exceptional constellation: Wagner fighting openly and brutally on behalf of Russia in Ukraine. In that context, it suddenly became easy for Western states to say: “PMCs are on the wrong side” – and to rediscover all the legitimacy, accountability and sovereignty problems that had long been downplayed when these companies were primarily tools of Western security policy. That moment of moral clarity was real, but it was also highly contingent: it depended on who was hiring the PMCs and against whom they were deployed. Our collective attention span has also proved remarkably short: as interest in Ukraine and Wagner receded from the headlines – especially after the failed insurrection and the subsequent “mysterious” deaths of Prigozhin and Utkin, Wagner’s former leaders, the broader moral reckoning with PMCs faded as well, even though Wagner continues to operate across multiple African countries with undiminished brutality and impunity.

The situation in Gaza shows how quickly this clarity erodes, too. When an organization of former soldiers enters under the label of “humanitarian aid”, but operates with weapons, hierarchical command structures and political backing, we are back in the familiar grey zone: is this assistance, proxy warfare, or both? But here is what is crucial: we must look beneath the surface and understand the actual structure and motives behind such organizations. The Gaza Humanitarian Foundation may present itself as a benevolent aid provider on first glance, but a closer examination might reveal that it as a geopolitical instrument that operates fundamentally at odds with the humanitarian mission it claims to embody. This gap between appearance and reality is precisely how privatized violence operates in this contemporary moment – it disguises itself, deploys different labels, adapts its rhetoric to changing political winds.

So yes, the brief moment in which PMCs could be neatly placed on the “wrong side” has passed. What we are left with is the harder, less comfortable task: to take our own arguments about PMCs seriously, even when it is “our” side that benefits from their deployment – and to develop the analytical tools to see through organizational facades and recognize geopolitical instrumentalization wherever it occurs.

Looking ahead, how do you see the future of war with regard to the use of PMCs? Are we moving toward a future without PMCs, or rather back to the early modern past with the active use of PMCs?

That ship has, in many ways, already sailed. PMCs are now firmly embedded in the contemporary security architecture and are not going away. In the current legislative and political climate, they are simply too convenient for too many actors: hegemonic powers that do not want to sacrifice their sons and daughters on the battlefield; smaller states that lack sufficient manpower; private entities facing security risks in unfamiliar environments; multilateral groups that lack institutional backing from the UN; actors who want clandestine operations; and international organizations under budgetary pressure that look for cheaper alternatives to traditional peacekeeping forces.

At the moment, war, violence, sovereignty, private actors – and Erik Prince – come full circle in Haiti. The Haitian government requested assistance to re-establish its monopoly on the use of force, as armed non-state groups control around 90 per cent of Port-au-Prince and exercise authority over large parts of the country. The Kenyan-led Multinational Security Support Mission in Haiti (MSS) lacked both capacity and backing, particularly as states, most prominently the U.S., have withdrawn from international cooperation such as peacekeeping or curtailed funding for the UN. In view of the failure to contain the violence, the Security Council in October authorized the creation of a “Gang Suppression Force”. However, even before that, the Haitian government hired Vectus Global, Erik Prince’s new PMC. Reportedly remunerated on a performance basis through a commission on customs revenues, Vectus will not only exercise governmental authority under virtually no control, but the state will also cede further inherently sovereign functions – such as revenue collection – to a private actor.

What we are seeing today is that military strength, security and power are no longer organized primarily through constitutional principles, values and norms, but increasingly according to the rules of the market. Military services are treated like any other sector of the economy, aligned with efficiency, cost‑effectiveness, competition and growth, even though force, as part of a state’s monopoly, is neither meant nor able to serve particular private interests. In this process, buyers and sellers commodify not only the historically evolved bond between nation state and standing army. Privatization also shifts power from the center of democratic legitimacy to its margins, as private actors gain authority while democratic control recedes. With each deployment of PMCs, the state allows its monopoly on the use of force to erode and undermines the contractarian foundations of its own legitimacy. That is why a fundamental reassessment of military outsourcing is urgently needed – not only for humanitarian reasons, but also for what it means for the future of the state itself.