Military Aid to Russia and International Law

North Korea’s leader, Kim Jong-un, is in Russia to discuss military support, including supplying artillery shells and rockets, for Russian operations against Ukraine. In the past, North Korea has supplied the Wagner Group with arms and ammunition. Its support to Russia is expected to grow as Pyongyang seeks Russian assistance for its own weapons programs and tries to enhance its international influence. In response, U.S. National Security Adviser Jake Sullivan has warned, “Providing weapons to Russia for use on the battlefield to attack grain silos and the heating infrastructure of major cities as we head into winter to try to conquer territory that belongs to another sovereign nation—this is not going to reflect well on North Korea, and they will pay a price for this in the international community.”

If the deal goes through, North Korea will join Iran in providing arms and equipment that Russia relies on to maintain its war of aggression against Ukraine. And that support is very significant. To illustrate, the Wall Street Journal reported that in the six months between October 2022 and April 2023, “cargo ships have carried more than 300,000 artillery shells and a million rounds of ammunition from Iran to Russia” across the Caspian Sea. Perhaps best known are the hundreds (maybe thousands) of reconnaissance and attack drones and surface-to-surface missiles Iran has provided Russian forces, which have been used to attack not only military objectives but also civilian targets. Assisted by Iran, Russia is now copying the drones, with a goal of producing 6,000 by next summer.

Prior Articles of War posts examined aid and assistance to Ukraine, which I consider lawful (see here, here, here, and here). By contrast, this post explores the law governing the transfer of arms and equipment to Russia. I conclude that the Iranian and proposed North Korean military support is unambiguously unlawful on multiple grounds.

The Red Herrings

Before discussing why that is so, it is useful to dispense with two potential red herrings. The first is the question of whether military assistance standing alone triggers the use of force prohibition set forth in Article 2(4) of the UN Charter and customary international law, unless provided in self-defense or pursuant to Security Council authorization. In a recent International Law Studies article, Lieutenant Colonel Casey Biggerstaff and I explored the matter, concluding that, in certain limited circumstances, aid and assistance might qualify as a use of force (we hastened to add that “States have yet to meaningfully contend with the concept of indirect force, much less its precise contours”). Applying the criteria we discussed, I do not believe the arms and equipment provided to Russia amounts to a use of force by the States providing it, at least not yet.

The second red herring is the question of whether, and if so, when, aid or assistance to a belligerent in an international armed conflict makes the supporting State a party to the conflict. In an earlier Articles of War post, I explored this issue in the context of U.S. support for Ukraine, suggesting it could do so in certain circumstances. Whether that occurs depends on the nature of the assistance, the intent behind its provision, and its nexus with specific conduct of hostilities operations. Undoubtedly, Iranian aid is making a measurable contribution to the Russian war effort. Still, at least based on the information publicly available, it has yet to transform Iran into a party to this armed conflict. And even if it had, status as a party to a conflict does not alone violate international law. Instead, party status is a choice of law issue. Once a State becomes a party, it is subject to the international humanitarian law and law of neutrality rules binding on belligerents.

Neutrality

The treaty law governing the rights and obligations of neutrals and belligerents is found in two of the 1907 Hague Conventions: Convention (V) Respecting the Rights and Duties of Neutral Powers in Case of War on Land and Convention (XIII) Concerning the Rights and Duties of Neutral Powers in Naval War. Iran, Russia, and Ukraine are party to both, whereas North Korea is party to neither. Most of the military supplies provided to Russia support land operations governed by Hague Convention V. Unlike Hague Convention XIII (see art. 6), it contains no provision banning inter-governmental support. Instead, the only provision related to support of a belligerent is Article 7, which provides, “A neutral Power is not called upon to prevent the export or transport, on behalf of one or other of the belligerents, of arms, munitions of war, or, in general, of anything which can be of use to an army or a fleet.”

However, the fact that the treaty does not address intergovernmental transfers such as those engaged in by Iran and (possibly) North Korea does not render them lawful. On the contrary, customary law has long prohibited such transfers. The Department of Defense Law of War Manual accurately articulates the rule (§ 15.3.2.1):

Neutral States have an obligation to refrain from providing war-related goods and services to belligerents. A neutral State is prohibited from supplying a belligerent State in any manner, either directly or indirectly, with warships, ammunition, or war material of any kind.

In support, the Manual cites a 1902 Attorney General Opinion, Neutrality—Military Supplies—Horses, thereby demonstrating the rule’s long lineage. The scholarly community is in accord. For instance, in his classic 1984 piece on neutrality, Yoram Dinstein observed, “A neutral State must not assist the war effort of one of the belligerents against its adversary through military supplies furnished on an inter-governmental basis. . . . No doubt, this is the general norm in respect of any type of weapons, munitions and war materials to the extent that inter-governmental transactions are involved” (14 Israel Yearbook on Human Rights 80).

This rule would appear to make any military aid and assistance to a belligerent unlawful. Yet, the existence of two approaches to how neutrality law applies complicates matters (see here).

By the first, so-called “strict neutrality,” the rules regarding transfer of arms apply equally to all neutral States and without distinction between the belligerents (see Pete Pedrozo’s analysis). Military aid to a belligerent is unlawful without qualification. But a second view, which the United States has long advocated, takes a different tack, that of “qualified neutrality.” As the DoD Law of War Manual notes, “before its entry into World War II, the United States adopted a position of ‘qualified neutrality’ in which neutral States had the right to support belligerent States that had been the victim of flagrant and illegal wars of aggression” (§ 15.2.2). Today, the United States takes the position that “[t]he Charter of the United Nations and decisions by the U.N. Security Council may, in certain circumstances, qualify rights and obligations under the law of neutrality” (§ 15.2.3).

The relevant aspects of the Charter are the prohibition on the use of force (art. 2(4)), the right of self and collective defense (art. 51), and Security Council authorization for a use of force (ch. VII). Wolff Heintschel von Heinegg and I have separately contended that the self-evident nature of Russia’s aggression justifies the application of the qualified neutrality doctrine in this case. Extensive State practice of providing Ukraine aid and assistance supports this contention, for there is no other legal basis justifying that practice.

But even though aid and assistance to Ukraine are, in my estimation, lawful, the fact that Russia is engaged in aggression against Ukraine precludes it from benefiting from the doctrine. Thus, by any reasonable reading of the law, support to Russia is an unambiguous violation of the customary law of neutrality under both the strict and qualified neutrality approaches.

I have heard it suggested that aid to Russia might be justified as a “collective countermeasure” despite that neutrality violation. A countermeasure is an act or omission by a State that would be unlawful but for the fact that it is a proportionate response to another State’s breach of a legal obligation the latter owes it and that is designed to compel that State to cease and/or provide any reparations due under the law of State responsibility (International Law Commission, Articles on State Responsibility (ASR), arts. 22, 49(1)). Collective countermeasures are analogous to collective defense (UN Charter, art. 51) in that third States either assist a State entitled to take a countermeasure or carry out the countermeasures on its behalf and at its request.

The argument in these circumstances would be that by the strict neutrality approach, Ukraine is violating neutrality law by accepting aid from neutral States that themselves are violating that body of law. This gives Russia the right to take countermeasures against Ukraine. In doing so, it has sought the assistance of other States to execute or even perform them, including by supplying otherwise unlawful materiel support.

This is a flawed argument from many angles. For instance, it is debatable whether military support to Ukraine is unlawful (qualified neutrality). Moreover, the right to engage in collective countermeasures is controversial. Sean Watts and I have argued that they are lawful, but in doing so, we acknowledged the reasonableness of the competing views.

Most importantly, however, there is widespread consensus that countermeasures “shall not affect the obligation to refrain from the threat or use of force as embodied in the Charter of the United Nations” (ASR, art. 50(1)(a)) or “other obligations under peremptory norms of general international law” (ASR, art. 50(1)(d)). In the latter regard, both the prohibition of aggression and the “basic rules of international humanitarian law” qualify as peremptory norms (see, e.g., International Law Commission, 2022 Draft Conclusions on Peremptory Norms, at 16; International Court of Justice (ICJ), Paramilitary Activities, para. 190; ICJ, Nuclear Weapons, para. 79). Providing any military aid enhances Russia’s ability to continue its unlawful use of force against Ukraine and Russia uses some of it directly or indirectly to engage in serious international humanitarian law violations, most notably drones and missiles that target civilian infrastructure. Countermeasures, including collective countermeasures, are clearly off the table even if the aid to Ukraine was unlawful.

Aid and Assistance under the Law of State Responsibility

The law of State responsibility regulates a number of situations in which one State may be held responsible for acting in support of the unlawful activity of another. Two are relevant vis-à-vis the provision of military aid to Russia. The International Law Commission’s ASR, which are considered a generally reliable restatement of customary international law, address them both.

Article 16 sets forth the first. It provides,

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.

The ICJ confirmed the customary law character of Article 16 in the 2007 Bosnian Genocide judgment (para. 420).

Obviously, if Iran or North Korea engaged in the same unlawful conduct as Russia, they would violate international law. Moreover, it cannot be doubted that Iran knows that its military aid supports Russia’s continuing unlawful use of force and that some of it is being used to strike civilian targets in violation of international humanitarian law. As to North Korea, any military aid to Russia would plainly fall within the ambit of Article 16 due to the self-evident unlawfulness of Russia’s use of force. And should it become apparent that its aid was being used for unlawful attacks under international humanitarian law (see also here), North Korea would also shoulder legal responsibility on that basis.

Applying Article 16 can be complex, as Marko Milanovic has demonstrated here and in his comprehensive International Law Studies article on intelligence sharing. For instance, there has been extensive analysis in the scholarly literature of such issues as the requisite causal nexus between the aid or assistance and the underlying internationally wrongful acts, as well as whether, and if so, how, intent should be read into Article 16(a)’s knowledge requirement. But in this case, the arms and equipment directly make Russia’s unlawful operations possible. Furthermore, it would be absurd to suggest there is a lack of intent (if intent is required) when the support’s very purpose (and highly visible use) is to enable operations that are barefaced international law violations.

The second basis for finding States supplying Russia responsible for an internationally wrongful act is captured in Article 41(2) of the ASR. It provides, “No State shall recognize as lawful a situation created by a serious breach [of a peremptory norm], nor render aid or assistance in maintaining that situation.” As noted, the prohibition on the wrongful use of force and the type of international humanitarian law violations engaged in by Russia are paradigmatic examples of peremptory norms.

It is important to caution that States supporting Russia with military aid are not legally responsible for Russia’sunlawful actions. Under the law of State responsibility, they only bear legal responsibility for their aid’s contribution to the underlying unlawful Russian conduct (ASR Commentary, art. 16, paras. 1, 10). This distinction would be relevant should Ukraine avail itself of its right to take countermeasures against these States (or turn to other States for assistance in taking them) because countermeasures must be proportionate to the wrongful conduct to which they respond (ASR, art. 51). Similarly, the distinction would bear on the extent of reparations (ASR, art. 31) due to Ukraine as a result of the assisting States’ military aid to Russia.

Only if the military aid is an essential and integral aspect of Russia’s wrongful operations would the States providing it be jointly and severally responsible for Russia’s unlawful actions. This is most likely in jointly planned operations or where the wrongful conduct could not have occurred but for the aid. Although that arguably might be the case with some of the attacks on civilian infrastructure, responsibility on this basis would be a harder case to make than that set forth by Articles 16 or 41 (ASR Commentary, art. 16, para. 10).

Common Article 1 of the Geneva Conventions

Common Article 1 of the four 1949 Geneva Conventions provides, “all High Contracting Parties undertake to respect and to ensure respect for the present Convention in all circumstances.” The International Committee of the Red Cross (ICRC) has cited the provision as reflecting customary international law, and rightly so (Customary IHL Study, rule 139).

For many years, there has been a debate among international law scholars and States as to the meaning and scope of application of the “respect” and “ensure respect” obligations. In particular, discussion has revolved around two issues: whether the ensure respect obligation imposes a duty on States not party to the conflict to affirmatively take measures to convince a State violating international humanitarian law to desist and whether the obligation applies in non-international armed conflict. These issues have been deconstructed in two International Law Studies companion pieces (Schmitt & Watts and Zwanenburg).

However, those are not the issues at hand. To begin with, this is an international armed conflict. More significantly, the question here is whether States providing military aid have a negative duty to refrain from supplying Russia, which has used some of it in international humanitarian law violations. They do, although there is some question as to whether the duty derives from the obligation to respect or to ensure respect. I take the former position, while the ICRC has taken the latter (Geneva Convention I Commentary 2016, art. 1, para. 154). But we agree there is a negative obligation borne by all States, whether a party to the conflict or not, to refrain from aiding or assisting violations of international humanitarian law. This is consistent with the ICJ’s Nicaragua judgment finding that States may not encourage persons or groups to violate that law (paras. 220, 255-56). The ICRC takes the position that the obligation not to encourage violations is customary in character, a position with which I agree (Customary IHL Study, rule 144). Indeed, few means of encouraging international humanitarian law violations are more effective than providing the violating State with the weapons systems used to engage in them, as is the case with Iran.

Violation of U.N. Security Council Sanctions

As a result of North Korea’s nuclear and ballistic missile programs (see Schmitt & Tramazzo), the UN Security Council, acting under Chapter VII of the UN Charter, has passed a series of binding resolutions prohibiting, inter alia, the export of certain arms by North Korea. Most notably with respect to North Korea’s support to Russia, the Council banned the transfer of “battle tanks, armoured combat vehicles, large calibre artillery systems, combat aircraft, attack helicopters, warships, missiles or missile systems [and certain other items subsequently identified] by their nationals or from their territory” (Security Council Resolution 1718, para. 8). Later resolutions “recalled” Resolution 1718, which remains in effect (see, e.g., Resolution 2397 (2017)).

Thus, the transfer of, for instance, artillery shells by North Korea would violate the ban. It must be remembered that pursuant to Article 25 of the UN Charter, “Members of the United Nations agree to accept and carry out the decisions of the Security Council.” This means that if North Korea transfers such material to Russia, Russia would also violate the ban.

Finally, according to the U.S. State Department, Iran’s transfer of drones to Russia violated UN Security Council Resolution 2231 (2015), which supported the Joint Comprehensive Plan of Action. This conclusion is highly technical but appears accurate as a matter of law.

Conclusion

International law is clear. The supply by any country of weapon systems, arms, ammunition, or other military equipment to Russia violates the law of neutrality. Additionally, such transfers amount to internationally wrongful acts under the law of State responsibility. They also breach the customary international law obligation to respect international humanitarian law that also appears in Common Article 1 of the 1949 Geneva Conventions. Finally, a transfer by North Korea would constitute a breach of binding Security Council resolutions by both North Korea and Russia, while Iran has already violated a Security Council ban.

***

Michael N. Schmitt is the G. Norman Lieber Distinguished Scholar at the United States Military Academy at West Point. He is also Professor of Public International Law at the University of Reading and Professor Emeritus and Charles H. Stockton Distinguished Scholar-in-Residence at the United States Naval War College.

Photo credit: Kremlin.ru