Symposium on PMSCs: Use of Maritime PMSCs, Weapons Procurement and Predatory Recruitment – New Frontiers in PMSC Regulation

[Andres Macías-Tolosa is a professor and researcher at Universidad Externado de Colombia, coordinator of the OPERA Research Group and editor of the OPERA Journal.  

Joana de Deus Pereira is a senior research fellow at RUSI Europe, co-founder of the Private Military and Security Companies (PMSC) Research Group at King’s College London, adjunct professor at Sciences Po, Paris, and visiting senior fellow at the International Centre for Policing and Security at the University of South Wales. 

Jovana Jezdimirovic Ranito is an assistant professor at the University College Twente in the Netherlands and founder of PrivSecNet. 

Michelle Small is a senior lecturerin international relations at the University of the Witwatersrand, Johannesburg and an expert at the Peace and Security Action Committee (EISA).

The authors are all members of the UN Working Group on Mercenaries.]

The evolution in the provision of private military and security services around the world has become of significant interest for states, international organizations, the private sector, and civil society, among others. That interest revolves around the expansion of the private military and security industry, the existing regulatory frameworks governing their activities, the associated risks of human rights violations, the measures required to prevent such violations, and the responsibility of states to ensure accountability. On this matter, the work of the UN Working Group on the use of mercenaries as a means of violating human rights and impeding the exercise of the right of peoples to self-determination, has been of significant importance (hereinafter, UN WG on Mercenaries) Additionally, the UN Human Rights Council has consistently emphasized the need to strengthen oversight mechanisms to address these evolving challenges.  

This contribution elaborates on three specific trends that appear insufficiently prioritized in current regulatory discussions, highlights existing regulatory gaps and challenges, and calls for urgent regulatory attention. 

Maritime Security 

One of the emerging trends in private military and security operations posing significant challenges to existing regulatory frameworks governing Private Military and Security Companies (PMSCs) concerns maritime security. The UN increasingly identifies maritime security as integral to international peace and legal order, as evolving threats expose growing regulatory gaps.

PMSCs have played a central role in responding to piracy and terrorism targeting commercial shipping and maritime trade routes, shifting their operations from traditional land-based activities towards increasingly complex roles in international waters. Protection provided by PMSCs not only reduces the risk of piracy attacks on contracted vessels but also lowers the likelihood of attacks on nearby vessels by approximately 7%.

More recently, with significant downsizing of the industry, a consequence of reduced high-risk areas, regulatory problems observed are related to regulation of the floating armories (FAs). While the UN Working Group on Mercenaries addressed a number of regulatory challenges related to use and operations of maritime PMSCs (2022), operations of the floating armories continue to raise concerns. Recent incidents of sinking vessels used as FAs close to conflict areas, without international oversight of transfer/management of stockpiles on them, raise further concerns about their regulation. While the International Maritime Organization does not have specific regulatory framework guiding operations of FAs, the UN Convention on the Law of the Sea (UNCLOS) addresses criminal jurisdiction on board of a foreign ship, which is quite limited in relation to territorial waters, and shifts responsibility mainly to regulate activities and operations of FAs to Flag states. As Flag States do not have (in general mode) particular oversight mechanisms of FAs, nor do they perform their audits, there is a clear gap in oversight of the global operations of FAs.  

Furthermore, considering oversight of weapons and operations of maritime Private Security Companies (PSCs), there are concerns that even though some Flag States have quite a comprehensive regulatory framework regarding registration and certification of maritime PSCs, they often lack oversight capabilities, and depend on documented reports only. For instance, inspections of vessels using PSCs staff, to verify if arms are properly stored, if they are operational, or living/working conditions of the staff operating on vessels, are not a common procedure. Additionally, concerns over PSCs employees’ rights relate to difficulty reporting potential abuse, lack of payment or poor working conditions incompatible with Flag State national laws. This is a consequence of widespread hiring by maritime PSCs across the globe, including in less developed countries, unaware of their rights under Flag States national law.  

All these constraints are becoming more important in a context where PMSCs are increasingly recognized as critical non-state actors in maritime security, and questions arise regarding their de facto substitution of state responsibilities in this domain (see Anwar et al, Cusumano and Ruzza and Arifin) as well as lack of international regulatory mechanisms responsible for global oversight.  

Weapons Procurement and Transfers 

A second emerging issue concerns the role of PMSCs in arms procurement and transfer activities. The arms trade network has changed and PMSCs possess an increasing capacity to procure arms and facilitate weapons transfers to states and non-state clients.  

While many states have legal, regulatory, and contractual provisions in place regarding PMSCs involvement in the ‘sub-delegation’ of the acquisition of arms and weapons that follows tracing, recording, and ‘end-certification’ processes, some do not. PMSCs involvement in arms procurement risks undermining existing arms control regimes and oversight mechanisms, the majority of which are State-focused, as well as falling outside of them (see Petersohn, Nebolsina, Patel and Jha and A/HRC/57/45). 

Instruments such as the Firearms Protocol, Arms Trade Treaty, and the Convention on Prohibitions or Restrictions on the Use of Certain Conventional Weapons do not recognize the possibility of PMSCs engaging in weapons transfers. Similarly, the Montreux Document ‘best practices’ and the ICoCA ‘Code of Conduct’ – neither of which legally binding instruments – place the responsibility of arms acquisition and transfer on contracting, home and territorial states.  

In conflict and/or weak governance settings, PMSCs have engaged in acquisitions and transfers on behalf of States that do not follow established procedures of registration and end-user certification. This entails the use of brokers, intermediaries, and the fabrication of documentation. PMSCs have also acquired weapons via state ‘re-routing’ (i.e. the diversion of a legal state-state transfer, that is re-routed onto the PMSC for use, sale, transfer). This complicates the traceability, end-user verification process, and control over arms transfers. These practices have been flagged as creating heightened risks of diversion to sanctioned armed groups, in violation of UN Security Council arms embargoes.Of particular concern is the growing nexus between PMSCs and “grey and black markets, networks and financing”.

Emerging technologies, such as uncrewed aerial systems and 3D printed weapons ‘ghost guns’, represent a new frontier not only in weapons development and manufacturing, but also in the expanding operational capabilities and commercial activities of PMSCs. PMSCs have been connected to the supply and sale of such additive components as a means of self-funding, raising concerns about PMCSs connections to illicit networks, their ability to raise illicit funds, and the circulation of unmarked, unverified weapon components and technologies. Moreover, the increasing availability of dual-use technologies — applicable for both civilian and military purposes — further complicates oversight, blurring the line between legitimate trade and unauthorized proliferation, and challenging existing export control regimes (see Bromley & Holtom). 

PMSCs are also increasingly engaged in utilizing digital tools and cyber-technologies for surveillance, intelligence gathering, operational planning and targeting in conflict and non-conflict situations. This growing reliance on cyber-enabled services is likely to persist and expand, yet currently unfolds within a largely unregulated international legal framework. In some cases, PMSCs have even been implicated in the development and operation of offensive cyber capabilities, raising significant concerns under international law governing cyber operations.

Predatory Recruitment Practices 

Another emerging trend concerns the growing prevalence of exploitative or predatory recruitment practices. The involvement of PMSCs in conflict, post-conflict, and proxy war contexts has intensified recruitment efforts, facilitated by globalized labor markets. While recruitment often adheres to national and international standards, there is increasing evidence that PMSCs exploit vulnerabilities among prospective recruits, leading to abusive and coercive labor practices, in violation of applicable human rights obligations. 

The Global South has become a key labor pool for PMSCs, exacerbating existing inequalities based on citizenship, socioeconomic status, gender, social class, and race. These disparities render PMSC personnel particularly vulnerable to exploitation and labor rights violations. This practice became even more evident in the aftermath of COVID-19, as migration of individuals seeking better employment opportunities in other countries increased; and also among prisoners, in many cases serving sentences in states different from their own nationalities, where they are offered amnesty or pardon deals in exchange for enlisting in PMSCs. 

Recruitment is often conducted through internal databases, digital platforms, and targeted branding campaigns using provocative messaging and promises of lucrative compensation to attract highly specialized freelance personnel. However, emerging reports document instances where promised benefits are not delivered, where fraud and coercion occur, and where these practices amount to violations of international human rights norms.

Concluding Remarks 

The rapid diversification of PMSC activities underscores the urgent need for the international community to confront not only the traditional challenges associated with the outsourcing of military and security functions, but also the increasingly complex regulatory gaps emerging in new operational domains. These developments reveal a clear trend: PMSCs are no longer confined to conventional combat support or logistical roles but are extending into areas that directly affect the rights and safety of civilians, the integrity of international legal regimes, and the sovereign functions of States. 

The regulatory vacuum that persists across multiple domains –including maritime security, arms transfers, and labor practices–, poses serious threats to international human rights and international humanitarian law. This vacuum reflects not only regulatory gaps, but an erosion of the state’s monopoly on legitimate force, challenging attribution, effective control, and state responsibility. Without clear, enforceable international standards, PMSCs may continue to operate in legal grey zones, shielded from effective accountability mechanisms while exercising functions that often approach, or even replace, core State responsibilities. 

In this context, the work of the Open-ended Intergovernmental Working Group on PMSCs takes on renewed urgency. A robust, legally binding international instrument is indispensable to establish clear obligations for States, to regulate the transnational operations of PMSCs, particularly in emerging, hybrid, non-traditional domains, so as to ensure human rights abuses are prevented, and provide adequate access and remedy to justice.  

The effective regulation of PMSCs is not merely a technical legal challenge; it is a matter of upholding the foundational principles of international law, protecting human dignity, and preserving the accountability architecture upon which global peace and security depend. The current moment presents a critical opportunity for States, international organizations, and civil society to forge a comprehensive, future-proof regulatory framework that meets the evolving challenges of private military and security governance.