(Ця стаття також доступна українською мовою тут.)

On Wednesday, the Organization for Security and Co-operation in Europe (OSCE) released a Report On Violations Of International Humanitarian And Human Rights Law, War Crimes And Crimes Against Humanity Committed In Ukraine Since 24 February 2022. The report was written by three experts appointed to a special Mission pursuant to the OSCE’s Moscow Mechanism. The report marks an important next step in a long road to a full understanding of the illegal and criminal acts committed and suffered in the ongoing armed conflict between Russia and Ukraine.

The Mission was not asked to examine the legality of the Russian invasion itself. Nevertheless, the report flatly states that “Russia is the aggressor and therefore responsible for all human suffering in Ukraine, whether or not it results from violations of IHL and even when it is directly caused by Ukraine, because even that would not have occurred if Ukraine had not to defend itself from the Russian invasion.” As its title suggests, the report focuses on possible violations of international humanitarian law and international human rights law, war crimes, and crimes against humanity.

The report is based on publicly available information, the horrific contents of which are familiar to us all. The experts were not able to travel to Ukraine, and Russia declined to meaningfully engage with them. But though circumstances prevented the Mission from presenting much new evidence, the report is striking for the facts that it pulls together and the legal analysis it provides.

The report covers a shocking range of apparent war crimes, from rape and torture to deportation and the use of human shields. The report also examines the impact of the conflict on vulnerable groups. It deserves to be widely and fully read, though it is often painful to do so. This essay touches on three aspects of the report: the conduct of hostilities, the law of occupation, and human rights law. In each of these areas, the Mission’s legal analysis points to ways in which ongoing or emerging debates in international law will likely intersect with accountability efforts in Ukraine.

The Conduct of Hostilities

The Mission announces a basic methodological choice on the first page of the report:

A detailed assessment of most allegations of International Humanitarian Law (IHL) violations and the identification of war crimes concerning particular incidents has not been possible. Nevertheless, the mission found clear patterns of IHL violations by the Russian forces in their conduct of hostilities. If they had respected their IHL obligations in terms of distinction, proportionality and precautions in attack and concerning specially protected objects such as hospitals, the number of civilians killed or injured would have remained much lower. Similarly, considerably fewer houses, hospitals, cultural properties, schools, multi-story residential buildings, water stations and electricity systems would have been damaged or destroyed.

As the report later explains, a detailed assessment of particular incidents would require particularized evidence of what attacking forces intended and knew, what alternative weapons and tactics they could have used but did not, and what military advantage they were trying to achieve. None of this information was available to the Mission. Instead, the Mission inferred patterns of violations from the sheer scale of death and destruction unleashed by Russian forces on civilians and civilian objects. These results could not be plausibly explained by mistake, technological limitations, or military necessity (see here, here, and here).

The report examines two specific attacks. It concludes that the Mar. 9 attack on the Mariupol Maternity House and Children’s Hospital, which killed three people and injured many others, “constitutes a clear violation of IHL and those responsible for it have committed a war crime.” Essentially, the report finds that Russia’s multiple, conflicting explanations for the attack—Ukraine staged the attack; Russia carried out the attack but only after warning the patients and allowing them to evacuate; there was no airstrike but instead a mysterious landmine—are implausible, so the most plausible explanation for the available evidence is a deliberate attack on a hospital with full knowledge and without warning.

The report also concludes that the Mar. 16 airstrike on the Mariupol Drama Theatre, which killed approximately 300 people, “constitutes most likely an egregious violation of IHL and those who ordered or executed it committed a war crime.” Again, the report finds that Russia’s explanation—that the Azov battalion blew up the theatre—is baseless, so the most plausible explanation is that Russian forces deliberately attacked the theatre despite the word “Children” (in Russian) visible from a distance on both sides.

The Mission’s approach of inference to the most plausible explanation is methodologically sound. The Mission is not a court, and the report is not a criminal conviction. Its mandate is to identify possible violations of international law, including possible international crimes. Some military lawyers may criticize the Mission’s approach of inferring intent from results and inferring knowledge from circumstances. But the alternative is to indulge in speculation and hypotheticals, or to wait for an exculpatory explanation that will never come. Better to lay out the case and leave it to Russia to answer.


The Mission takes a strong position on the controversial question of whether the law of occupation applies all at once, when a state exercises complete authority and control over territory beyond its borders, or rule by rule, as a state’s ability to satisfy or violate the law expands or contracts. The Mission takes the latter view:

The Mission applies in this report a functional concept of occupation to the invasion phase under which certain rules of IHL of military occupation gradually start to apply to certain issues as soon Russia obtained control over those issues, while other rules do not yet apply. A systemic interpretation that takes the object and purpose of Convention IV into account leads to the conclusion that its rules on occupied territory must apply from the very moment the enemy assumes control over a person or an object in an invaded territory. To take an example, it seems absurd that the deportation of civilians would be allowed during the invasion phase but absolutely prohibited once the invasion turns into an occupation. Indeed, inhabitants of an invaded territory are enemy nationals encountering a belligerent on their own territory, which is precisely the situation IHL rules on military occupation were made to address. Under a sliding scale of obligations that apply according to the degree of control, negative obligations to abstain apply as soon as the conduct they prohibit is materially possible (such as when the person benefitting from the prohibition falls into the hands of the invading forces), while positive obligations to provide and to guarantee would apply only at a later stage. This sliding scale is also more adapted to the fluid realities of modern warfare and the absence of frontlines than the traditional ‘all or nothing’ approach. This approach also avoids the difficulty of determining when the invasion phase turns into the occupation phase.

This seemingly abstract question may have concrete implications. As the report indicates, the prohibition (and war crime) of forcible deportation protects civilians under occupation. The Mission’s functional concept of occupation underlies its statement that:

If (some of) these deportations [were] forcible (including because Russia created a coercive environment in which those civilians had no other choice than to leave to Russia) and as they necessarily concerned civilians who had fallen into the power of Russia as an occupying power, this violates in each case IHL and constitutes a war crime.

Interestingly, the report does not appear to draw an important connection between the functional concept of occupation and another of its topics: the application of human rights law.

Human Rights

The report observes that international human rights law continues to apply during armed conflict and that, in principle, violations of international humanitarian law also violate the human right to life of every person a state kills. At the same time, the report notes that the European Court of Human Rights recently ruled that the European Convention on Human Rights extends beyond a state’s borders to areas it militarily occupies, but not to areas of active hostilities. This ruling, from Georgia v. Russia (II), has been widely criticized (see here and here). Although the report itself does not explicitly draw the connection, its functional concept of occupation may provide one way to limit the ruling’s reach, ensuring the wider application of human rights law.

The report notes a number of allegations involving apparent “attacks against civilians walking or riding bicycles in the public space, driving in cars or travelling on trains,” all of which would constitute war crimes if confirmed. In some of these cases, it may be unclear whether Russian forces have already established full authority and control over the area, marking a clear break between hostilities and occupation. Under the Court’s previous ruling, this would leave the application of the Convention unclear as well. But if the functional concept of occupation is adopted, then such a clear break is not necessary. The negative obligations of the law of occupation would protect Ukrainian civilians as Russian forces advance through their cities and towns, even before these forces establish full control. The European Convention on Human Rights should protect them as well.

Alternatively, the Court has sometimes found that the Convention protects individuals who are neither in occupied territory nor physically detained by state agents. In the same Georgia v. Russia judgment, the Court described such cases as relating to “isolated and specific acts involving an element of proximity.” In principle, this category could be applied to attacks on individual civilians on the borderline between hostilities and occupation.

Finally, the report takes note of the view expressed by the UN Human Rights Committee (HRC) that every killing in furtherance of an act of aggression violates the human right to life of the person killed, whether or not that killing also violates international humanitarian law. The report observes that, “[i]f correct, this conclusion seems potentially applicable to the acts resulting in the violations of many other human rights, as long as there is a direct causal link between these acts and the act of aggression.” The HRC’s conclusion is correct (see here). Still, it is understandable for the mission not to rest too much of its analysis on this relatively new and still disputed view. But it might have taken note that the same conclusion follows under the European Convention (see here), as recently recognized by Judge Keller.


The OSCE report is mostly devoted to apparent war crimes committed by Russian forces for the simple reason that Russian forces have committed most of the apparent war crimes. Nevertheless, the report duly documents several possible violations of international humanitarian law by Ukrainian forces, including one apparent war crime against Russian prisoners of war which Ukrainian authorities have promised to investigate. While the report repeatedly states that Russian violations are “by far larger in scale and nature,” it remains legally, morally, and strategically imperative that Ukraine strictly adhere to international law.

International humanitarian law applies to aggressor and defender alike. Its rules do not depend on reciprocity or permit reprisals against prisoners or civilians. The basic truths are important to remember where, as here, Russian forces are engaged in “clear patterns of IHL violations,” and where, as here, “the state which starts an unlawful war is, at least politically and morally, if not legally, responsible for any death that occurs in the course of such an unlawful war.”


IMAGE: A police officer is reflected in the logo of the OSCE (Organization for Security and Cooperation in Europe) at the OSCE headquarters in the Hofburg Palace in Vienna February 21, 2022. (Photo by ALEX HALADA/AFP via Getty Images)