What do Appropriate Due Diligence Measures for Nonstate and Substate Partners Look Like? Part I: Outlining Partnership Patterns and the Legal Debate

[Erica Gaston is an international lawyer and non-resident fellow with the Global Public Policy institute (GPPi). She has been engaged in research on IHL and conflict-related human rights issues in Afghanistan, Iraq, Yemen, and other countries since 2007.]

In the last two decades, Western states have frequently worked with nonstate or substate armed groups to help confront security threats. The greater frequency of such partnerships has sparked interest in what measures states should take to address the their nonstate partners’ conduct and any risk of International Humanitarian Law (IHL) obligations flowing from that support. What legal obligations, if any, do Western states have to ensure that their nonstate or substate partners comply with international law or their own domestic standards?  Even if only on a policy basis, what measures do states take to try to deter or prevent abuses or misconduct by supported groups?

Many of the debates surrounding legal obligations for the conduct of partner forces dwell on the degree and scope of state responsibility – appropriately so given that this is an important but still gray area of the law. However, if we agreed that some degree of due diligence measures are appropriate, either on a policy or legal basis, what might those due diligence measures look like? The first part of this two-part blog will briefly outline existing patterns of state support to nonstate or substate armed groups, and introduce the debate over state responsibility and due diligence obligations potentially raised by such support.  Part II will then explore what due diligence measures might look like in practice, drawing examples from a recently published ODI-GPPi study on US efforts to mitigate the risks surrounding its nonstate and substate partners in Syria, Afghanistan, and Iraq. 

Partner Support Operations on the Rise

State support to militias, rebels, guerrillas, or other paramilitary forces is not a new feature of war. However, as a recent ICRC study observed, partner support operations – including with nonstate actors – are an increasingly prominent part of 21^st century conflict. With the greater relative power available to nonstate actors and the fragmentation of state institutions and structures in a number of countries, nonstate and substate forces are frequently security and political actors, acting in lieu of or alongside the state.  As a result, although Western states may prefer to work through state partners to address security concerns, in many peacekeeping, stabilization, or counter-terrorism contexts, nonstate or substate forces may be the best, or simply, the only available partners. 

The US has been the most active in mobilizing and partnering with nonstate armed groups and other substate forces. In Iraq and Afghanistan from 2006 to 2013 the US collectively mobilized some 120,000 tribal and community forces and militias as local counter-insurgents. The US provided support to a range Syrian nonstate armed groups, from select groups of the Free Syrian Army, to prolonged support to the Kurdish-led Syrian Democratic Forces in northeast Syria. In addition to such large-scale support, US Special Forces and intelligence agents have regularly turned to militias, clan forces, tribal groups, or nonstate (or questionably quasi-state) armed groups as auxiliary forces for global counter-terrorism missions. This has been prominent in Afghanistan, Somalia, Syria, Iraq, and Libya, but may also have taken place in any number of the other 80-plus countries where US Special Forces operate annually.

While US forces have been more open to supporting nonstate and substate armed groups, they are not alone. France’s engagement in the Sahel has frequently involved ad hoc partnerships with nonstate militias. In Afghanistan, British leaders were the first to publicly propose that NATO embrace a tribal mobilization strategy, and British Special Forces have reportedly worked covertly with some of the same nonstate and quasi-state actors as American Special Forces have. British and French Special Forces both partnered with or helped train and supply opposition forces in Syria, providing covert support to some Free Syrian Army groups and more open engagement, training, and cooperation with anti-ISIL forces, particularly the Syrian Democratic Forces.

Other Western states have been more reluctant to engage with nonstate armed groups, but have sometimes been forced into positions of tacit, de facto, or limited cooperation. The Netherlands also provided non-lethal assistance to some Free Syrian Army groups, and Denmark cooperated with US Special Forces in training and supporting Iraqi tribal groups operating as cross-border auxiliary forces in Syria and Iraq. The UK and even Germany considered providing limited support or training to the partially state-recognized Darwish militias (at 122) in Somalia. In Afghanistan, up until major withdrawals in 2014, the Netherlands, Italy, France, Norway, the UK and Germany frequently faced the dilemma of how to deal with militias, warlords, and other powerful nonstate armed groups in the provinces or regions they took charge of. While some of these militias had some legal cover – links with state officials, some quasi-state designation, or acting as private security forces – in many cases the veneer was thin or temporary and the level of de facto engagement or cooperation that troops on the ground adopted to meet security needs was controversial.

This last example points to the porous line between state and nonstate actors, and to the reality that in all but name many international actors are de facto cooperating with or even supporting non-state armed groups, and have to consider the risks involved. In some cases, non-state armed groups or militias have been brought under state institutions or given quasi-official designations in part to legitimize them and facilitate external support. This was the case with the Afghan Local Police and the sahwa  (Awakening forces) in Iraq, and has been proposed with some Darwish in Somalia. However, in many situations this legal status is imperfect; may not include all members of a group; or may shift over time. It also often fails to bring about meaningful state authority and control over the groups in question, and thus does little to shift the underlying IHL or political risks associated with irregular forces.

In other situations, although the group in question may hold the title of state forces, there is little to distinguish them from the many other irregular, hybrid, or nonstate forces operating in the same territory, including on conduct and protection grounds. In Libya, a range of European countries, including the UK, France, and Italy, have provided substantial support to Libyan security forces. However, as one European advisor commented, “There’s a difference between what program documents in Brussels say and what they know they’re actually doing on the ground. In Libya they might be dealing with something that calls itself the coast guard or highway police, but really it’s just another variant of militias.” As such, although states may cling to the idea of providing support only to state actors, they may inadvertently support non-state armed groups and partisan forces, with all the attendant political and conduct-based risks that come with that. During the anti-ISIL campaign in Iraq, more than a dozen Western countries provided support to the Kurdish Peshmerga; although support was intended to go only to the unified “Regional Guard Brigades,” in practice much of the training and arms went to the stronger, party-aligned Peshmerga forces (the so-called Division 70 and Division 80 forces), which are more often classed as partisan militias or hybrid armed groups.  

As these examples illustrate, Western states’ engagement or support with non-state armed groups runs the gamut from direct mobilization and a degree of direction and control, to simply tacit cooperation or recognition of these groups as de facto security providers. The legal status of these groups also varies. While some are clearly nonstate armed groups by any definition, others have been granted a degree of legal title or recognition. Given these variations in status, this article will generally refer to these groups as nonstate or substate actors, and note specific status designations as relevant.

Legal Debates over State Responsibility & Due Diligence Measures

There has been a long and fervent legal debate about the degree of state responsibility for partner forces operating in other states. Under the Draft Articles of State Responsibility, states may be held responsible for the conduct of groups or persons who are acting under their instruction, direction, or control, even where not an official agent or subunit of that state. Under Article 8 states could be held responsible for wrongful acts of nonstate partners where the group is acting under the state’s instructions, direction, or control. Under Article 16 states can be responsible for the conduct of the forces of another state, where the supporting state had knowledge of the circumstances surrounding the wrongful act. This ‘knowledge of circumstances’ criterion has generally been interpreted as signalling either a degree of intent to facilitate the wrongful act in question, or a degree of knowledge or foreseeability (at p. 20-23) that the wrongful act would follow from support.

The Draft Articles provisions on state responsibility largely draw from the legal framework set out in the International Court of Justice’s 1986 Nicaragua decision. In that decision, the ICJ found that a state sponsor can be accountable for the conduct of a nonstate armed group where it has “effective control of the military and paramilitary operations in the course of which the alleged violations were committed” (at ¶ 220). However, the application of this principal to the contras at issue in the Nicaragua case established a very narrow interpretation of what might constitute “effective control.” Despite recognizing evidence that the US was “financing, organizing, training, supplying and equipping” the armed groups in Nicaragua, and even involved in the “selection of its military or paramilitary targets, and the planning of the whole of its operation” the court found that this did not constitute “effective control” sufficient to find state responsibility.

Given such a high bar, none of the nonstate armed group relationships described above might meet this “effective control” standard. The knowledge, intent, or foreseeability standards variously applied where state forces are concerned have been equally difficult to find in practice (at ¶ 17). Nonetheless, even if not fully meeting this bar of direct attribution, there might still be some degree of liability or obligation on a theory of complicity or aiding and abetting third party violations, or under the general obligations of human rights law (Of note: there has been a healthy debate about this in the context of mistreatment of ISIL detainees by the US’ Syrian partners).

In addition, and perhaps the more interesting terrain for speculation for this article, there is the question of “due diligence” obligations under IHL. Common Article 1 of the Four Geneva Conventions and Additional Protocol I obliges all state parties “to respect and ensure respect for the [Conventions] in all circumstances.” The Nicaragua decision (at ¶ 220) interpreted this obligation as requiring states “not to encourage” persons or groups from violating IHL. Thus states should ensure respect, and should not knowingly assist or enable IHL violations, but to what degree are they obligated to take affirmative steps to ensure IHL compliance?

The larger weight of scholarship and opinio juris tips toward some degree of affirmative duty (at ¶158) or proactive steps (at p. 32), even more so where a third-party state has some degree of influence or control over the circumstances in question (i.e. through support and sponsorship). However there is still a great deal of gray area in terms of what might satisfy this due diligence obligation. Dormann and Serralvo offer examples of states enforcing sanctions against other states not in compliance (an approach that might also arguably be applied to nonstate actors), or the panoply of regulations and restrictions attached to arms export. Domestic and international frameworks governing arms export, trade, and assistance tend to be at least partly motivated by the responsibilities invoked under Common article 1 as well as other treaty obligations to prevent weapons transfers that might contribute to serious violations of IHL or human rights (see, e.g., here, here, and here). 

Outside of arms control measures, what “proactive steps” should states take to influence nonstate or substate forces’ behaviour where support is being provided? Discussing a sort of voluntary due diligence policy where states support civil defense groups, Bruce Oswald suggests that sponsoring states might ensure there is training, establish codes of conduct, facilitate external monitoring or reporting, or take steps to ensure that investigations and follow-on accountability mechanisms are possible for the groups in question. A newly released ICRC study on partner support suggested that both funding cuts and funding increases might constitute appropriate due diligence measures: “short-term measures to halt or withdraw support” might provide potent sticks, deterring problematic behaviour, the study noted (at p. 25); but where non-compliance was due to lack of capacity to implement IHL, additional support might be more effective. The latter implies some investment in training, advising, and other capacity-building measures.

Do we see examples of these sort of due diligence practices happening in state engagement with nonstate or substate partners? What steps do states take to try to deter or address potential human rights or IHL violations by groups they support? A recent study I conducted examined ways that the US has tried to mitigate the risks surrounding nonstate or substate partners in Syria, Afghanistan, and Iraq, including by provision of training, monitoring, setting rules and standards, establishing sanctions, and other mechanisms. Should such measures be considered an example of emerging practice? A potential blueprint for appropriate due diligence measures? Part II of this blog will explore this practice and those questions in greater detail.