It is widely known that the US is facing numerous challenges in arming and training a select number of fighters as part of a group known as the “New Syrian Forces,” which are part of the Free Syrian Army’s Division 30, in order to fight ISIS on the ground in Syria. A paltry fifty-four such fighters have completed the “train and equip” program so far, with the Pentagon now vetting and training additional fighters. In mid-July, the freshly trained unit was deployed into Syria, but the Nusra Front abducted a number of fighters on July 28, and stormed their encampment on July 31, capturing, wounding or killing several more. Other fighters left the area, and a number went unaccounted for. Last Sunday, the Nusra Front released seven Division 30 fighters, but a Pentagon official anonymously claimed US-trained fighters were not among them.

A number of questions of international law emerge from the US “train and equip” program, some of which were explored in Michael Schmitt’s post earlier this month. An additional question that merits some consideration is the relationship between the US and “New Syrian Forces” fighters, and whether the US bears any responsibility for these fighters’ actions should they commit violations of international humanitarian law.

Reports indicate that special operations forces working under US Central Command are leading the “train and equip” program. At the outset, the program aimed to provide “basic military gear, including ammunition, small arms, trucks and machine guns to mount on them.” We know today the US has provided fighters with heavy machine guns, communications technology, and laser pointers for directing airstrikes. The fighters also receive a stipend from the US.

When the program was launched, the Pentagon declared it would “not have direct tactical control over the trained units once they deploy in Syria,” but instead would be “establishing links” with fighters so the US could “exert indirect influence on Syria’s chaotic battlefield.” Today, the fighters are said to have direct contact with the US-led coalition, but report to Syrian commanders. US Central Command spokesman Col. Pat Ryder has said the fighters are not under US command and control. Once trained, they return to Syrian rebel groups with whom the US has been working. Ryder has added, “[a] key aspect of the Syria Train and Equip program is to train these personnel as units to effectively fight together, which includes training and developing their leaders and ensuring they have a chain of command that can lead forces effectively and appropriately”.

Now, how do these facts fit into the legal framework on State responsibility? Under international law, a State commits an internationally wrongful act when an act or omission is attributable to it and constitutes a breach of its international obligation. A State will bear international responsibility for such a wrongful act, with one of the legal consequences being the obligation to make full reparation for the material or moral injury caused by that act.

As for when a State is responsible for the conduct of a person or group that is not a State organ or empowered to exercise governmental authority, the International Law Commission has set out the following rule:

The conduct of a person or group of persons shall be considered an act of a State under international law if the person or group of persons is in fact acting on the instructions of, or under the direction or control of, that State in carrying out the conduct. [Emphasis added]

In the 1986 Military and Paramilitary Activities in and against Nicaragua decision, the International Court of Justice (ICJ) was faced with deciding whether to attribute the contra forces’ actions to the US, which had largely financed, trained, equipped, armed and organized their military and paramilitary activities. The US had also collaborated closely with the contras to decide and plan operations on the basis of intelligence and logistical support that it had provided to them. The Court held:

that United States participation, even if preponderant or decisive, in the financing, organizing, training, supplying and equipping of the contras, the selection of its military or paramilitary targets, and the planning of the whole of its operation, is still insufficient in itself, on the basis of the evidence in the possession of the Court, for the purpose of attributing to the United States the acts committed by the contras in the course of their military or paramilitary operations in Nicaragua. All the forms of United States participation mentioned above, and even the general control by the respondent State over a force with a high degree of dependency on it, would not in themselves mean, without further evidence, that the United States directed or enforced the perpetration of the acts contrary to human rights and humanitarian law alleged by the applicant State. Such acts could well be committed by members of the contras without the control of the United States. For this conduct to give rise to legal responsibility of the United States, it would in principle have to be proved that that State had effective control of the military or paramilitary operations in the course of which the alleged violations were committed. [Emphasis added]

In 2007, the ICJ reiterated the attribution test of “effective control” in the Application of the Convention on the Prevention and Punishment of the Crime of Genocide case. In deciding whether the Srebrenica massacres were attributable to the Federal Republic of Yugoslavia, the Court held:

Genocide will be considered as attributable to a State if and to the extent that the physical acts constitutive of genocide that have been committed by organs or persons other than the State’s own agents were carried out, wholly or in part, on the instructions or directions of the State, or under its effective control. This is the state of customary international law, as reflected in the ILC Articles on State Responsibility [Emphasis added]

Despite the standard of State direction, enforcement, instruction or effective control set out by the ICJ, the International Criminal Tribunal for the Former Yugoslavia (ICTY) articulated a different test in the Tadic case. (With the International Criminal Court later adopting the ICTY approach in the Lubanga case.) In Tadic, the ICTY was deciding whether the Federal Republic of Yugoslavia’s support for the Bosnian Serb armed forces rendered the armed conflict against the government of Bosnia and Herzegovina international. The Appeals Chamber distinguished the required degree of control over private individuals from the required degree of control over an organized armed group such as the Bosnian Serb armed forces. Because a member of an organized group that has structure, a chain of command, and a set of rules will conform to the group’s standards and be subject to its authority, it is sufficient for the group to be under the “overall control” of the State rather than the “effective control” described in Nicaragua. The ICTY explained:

international rules do not always require the same degree of control over armed groups or private individuals for the purpose of determining whether an individual not having the status of a State official under internal legislation can be regarded as a de facto organ of the State. The extent of the requisite State control varies. Where the question at issue is whether a single private individual or a group that is not militarily organised has acted as a de facto State organ when performing a specific act, it is necessary to ascertain whether specific instructions concerning the commission of that particular act had been issued by that State to the individual or group in question …. By contrast, control by a State over subordinate armed forces or militias or paramilitary units may be of an overall character (and must comprise more than the mere provision of financial assistance or military equipment or training). This requirement, however, does not go so far as to include the issuing of specific orders by the State, or its direction of each individual operation. Under international law it is by no means necessary that the controlling authorities should plan all the operations of the units dependent on them, choose their targets, or give specific instructions concerning the conduct of military operations and any alleged violations of international humanitarian law. The control required by international law may be deemed to exist when a State (or, in the context of an armed conflict, the Party to the conflict) has a role in organising, coordinating or planning the military actions of the military group, in addition to financing, training and equipping or providing operational support to that group. [Emphasis added]

Of course, the ICJ, and legal experts such as Dapo Akande, have disagreed with the Tadic test for various reasons. For instance, the ICJ has argued that the ICTY standard was used to determine whether or not an armed conflict was international, but that “logic does not require the same test to be adopted in resolving the two issues, which are very different in nature: the degree and nature of a State’s involvement in an armed conflict on another State’s territory which is required for the conflict to be characterized as international, can very well, and without logical inconsistency, differ from the degree and nature of involvement required to give rise to that State’s responsibility for a specific act committed in the course of the conflict.” Akande argues that the ICJ test for attribution of responsibility is correct, while the test of whether or not there is an international armed conflict is simply whether or not force has been used by one State against another, for example by training and arming non-state armed groups.

It may be tempting to consider another avenue of State responsibility for the actions of non-state actors. In 2013, the government of Austria shared its position against supplying arms to the Syrian opposition, stating, “Should supplied arms be used by armed opposition groups in Syria in the commission of internationally wrongful acts, the States who had supplied these arms and had knowledge of these acts would incur State responsibility for their aid and assistance in the commission of such acts.” The position referred to the Article on State responsibility for aiding or assisting in the commission of an internationally wrongful act: “A State which aids or assists another State in the commission of an internationally wrongful act by the latter is internationally responsible for doing so if: (a) that State does so with knowledge of the circumstances of the internationally wrongful act; and (b) the act would be internationally wrongful if committed by that State.”

However, as the rule clearly states, it applies to a State aiding or assisting another State. Referring to this as a test for “complicity,” Derek Jinks has explained why it only applies to assisting or aiding another State:

The structure of the rules suggests that the lower [complicity] threshold suffices for imputing the conduct of another state because the public character of any such acts is clear-that is, other states clearly have international legal personality. Attribution of the private acts, on this view, is appropriate only if the nexus between the state and the ostensibly private actor confers a public character on the conduct in question-recasts the private acts as “state action.”

Finally, by providing Syrian fighters with the means and skills to engage in war, the US also bears the obligation to ensure that they comply with IHL, even if the fighters’ actions aren’t attributable to it. Under Article 1 common to the four Geneva Conventions of 1949 and Additional Protocol I (and also considered to be part of customary law), States must ensure respect for IHL by other participants in an armed conflict. States “may not encourage violations of international humanitarian law by parties to an armed conflict. They must exert their influence, to the degree possible, to stop violations of international humanitarian law.” A useful and recent piece by Knut Doermann and Jose Serralvo explores the content of this obligation of due diligence, which has been reaffirmed by the ICJ as well as the UN Secretary-General, General Assembly and Security Council. The authors explain, “a State with close political, economic and/or military ties (for example, through equipping and training of armed forces or joint planning of operations) to one of the belligerents has a stronger obligation to ensure respect for IHL by its ally. This is precisely the underlying logic of CA 1 …” As what can be considered an offshoot of this, the Arms Trade Treaty, which the US has signed but not ratified, reiterates all States’ obligation to ensure respect for international humanitarian law and translates this into an explicit prohibition of weapons transfers if the transferring State has knowledge that the weapons will be used to commit certain war crimes. Short of such knowledge, a risk assessment must be carried out and the weapons withheld if an overriding risk of serious violations is found.

If we apply the Nicaragua test to what we know about US efforts to train and equip Syrian fighters, the US does not appear to be directing or enforcing the fighters’ actions or to have effective control over their operations. Even under the Tadic test applicable to a State’s influence over organized armed groups, it does not appear that the US is “organi[z]ing, coordinating or planning the military actions of the military group” (and this is assuming the fighters qualify as an organized group for the purpose of this test). Nevertheless, the US does have an obligation to use its influence wisely and cautiously, and to ensure that the fighters comply with international humanitarian law.