Following last week’s discovery of a mass grave containing some 450 bodies in the Ukrainian town of Izium, questions of international criminal culpability loom heavily.

“Russia left behind mass graves of hundreds of shot and tortured people in the Izium area. In the 21st century, such attacks against the civilian population are unthinkable and abhorrent. We must not overlook it. We stand for the punishment of all war criminals,” Czech Foreign Minister Jan Lipavsky, whose country currently holds the European Union’s rotating presidency, wrote Saturday via Twitter.

“I call for the speedy establishment of a special international tribunal that will prosecute the crime of aggression,” he wrote.

Since the earliest days of Russia’s invasion of Ukraine, world leaders and international organizations have called for investigations and prosecutions into alleged war crimes. As of the UN’s latest count, 5,916 civilians — including more than 300 children — had been killed in the hostilities, while 8,616 — more than 400 of them children — had been injured. But various bureaucratic hurdles ranging from Russia’s powerful role in the UN’s enforcement arm to jurisdictional matters have left the path to justice shrouded in uncertainty.

In this explainer, JURIST explores the events in Izium, and whether and how justice can prevail.

What happened in Izium?

Ukrainian authorities last week revealed the discovery of a mass grave in the forest surrounding the town of Izium, which until recently had been occupied by Russian forces.

“Russia is a terrorist country,” Ukrainian President Volodymyr Zelensky wrote via Twitter on Friday, in a post accompanied by photos of investigators exhuming bodies in a forested area surrounded by wooden crosses. “I don’t know why the world is slow to recognize it. We liberated Izium. Over 400 graves were found in the forest next to it. How many tortured Ukrainians are there is unknown. How many more of our people must die so that all finally figured it out?”

Ukraine’s Foreign Minister, Dmytro Kuleba, echoed the sentiment. “Mass graves in Izium prove that whenever we liberate territories, there is evidence of horrendous Russian crimes. One can only imagine the hell that people in other Russia-occupied territories still go through. We urgently need more weapons to liberate them and save their lives,” he Tweeted on Friday.

As noted in Lipavsky’s comments above, some of the bodies showed evidence of torture.  Official accounts have been corroborated by advocacy groups and journalistic reporting and photography from the site.

This is not the first mass grave to have been discovered in a recently liberated town since the start of Russian hostilities in Ukraine. In Bucha, a town near the capital city of Kyiv, hundreds of bodies were discovered in mass graves following a nearly month-long Russian occupation in March. 

Russia has denied claims that Russian soldiers were responsible for the atrocities allegedly carried out in both towns. Kremlin spokesperson Dmitry Peskov told reporters on Monday in quotes carried by The Moscow Times that what happened in Izium is “a lie and of course we’ll stand up for the truth in this entire story. … Kyiv is pushing the same scenario in [Izium] as it did with the provocation in Bucha.”

What efforts have been made so far to prosecute alleged war crimes in Ukraine?

The International Criminal Court (ICC) has launched an investigation into alleged war crimes and crimes against humanity that have emerged from the conflict. While Ukraine is not a state party to the Rome Statute, which established the ICC and which outlines the scope of its jurisdiction, Kyiv has accepted the court’s jurisdiction over Rome Statute violations that have occurred since Russia’s February 2014 annexation of Ukraine’s Crimean peninsula. Like Ukraine, Russia is not a state party to the Rome Statute, but unlike Ukraine, it has not consented to ICC jurisdiction over these matters.

The ICC can exercise jurisdiction over Russian actors with respect to the original crimes included in the Rome Statue — genocide, war crimes, and crimes against humanity. But further jurisdictional hurdles remain, particularly concerning the crime of aggression.

What is the crime of aggression?

The crime of aggression, which was added to the Statute in 2010 via Rule 8 bis, is defined in relevant part as:

The planning, preparation, initiation or execution, by a person in a position effectively to exercise control over or to direct the political or military action of a State, of an act of aggression which, by its character, gravity and scale, constitutes a manifest violation of the Charter of the United Nations

Acts of aggression can include the following:

(a) The invasion or attack by the armed forces of a State of the territory of another State, or any military occupation, however temporary, resulting from such invasion or attack, or any annexation by the use of force of the territory of another State or part thereof;

(b) Bombardment by the armed forces of a State against the territory of another State or the use of any weapons by a State against the territory of another State;

(c) The blockade of the ports or coasts of a State by the armed forces of another State;

(d) An attack by the armed forces of a State on the land, sea or air forces, or marine and air fleets of another State;

(e) The use of armed forces of one State which are within the territory of another State with the agreement of the receiving State, in contravention of the conditions provided for in the agreement or any extension of their presence in such territory beyond the termination of the agreement;

(f) The action of a State in allowing its territory, which it has placed at the disposal of another State, to be used by that other State for perpetrating an act of aggression against a third State;

(g) The sending by or on behalf of a State of armed bands, groups, irregulars or mercenaries, which carry out acts of armed force against another State of such gravity as to amount to the acts listed above, or its substantial involvement therein

In short, the mass graves, the surging civilian casualties, and many of the other alleged consequences of Russia’s invasion of Ukraine would fit cleanly into the definition of the crime of aggression.

Why can’t the ICC prosecute crimes of aggression in this case?

As explained by the American Society of International Law (ASIL), when the Statute took effect in 1998, the crime of aggression had yet to be fleshed out. At the time, the parties to the convention were unable to agree on a definition of the crime, or what would trigger the ICC’s jurisdiction over it. The original Rome Statute thus left a placeholder that would eventually contain the nuances of aggression under the court’s jurisdiction, ultimately resulting in differing scopes of jurisdiction between this and the earlier crimes included in the statute.

As a result, for the ICC to exercise jurisdiction over the crime of aggression, the aggressor must either be a state party to the Rome Statute, or be asked by the UN Security Council (UNSC) to investigate the matter. Again, Russia is not a state party. And to exacerbate matters, it is a permanent member of the UNSC, thus imbuing it with veto power that would prevent the latter scenario.

But precedent shows that bureaucratic obstacles such as these are far from insurmountable. And this is where Lipavsky’s call for a special tribunal could come into play.

How could a special tribunal take shape in this case?

Earlier this month, a how-to guide of sorts for the creation of a special tribunal for Ukraine was released by the Ukraine Task Force of the Global Accountability Network (GAN) — an international justice advocacy group led by David Crane, former Chief Prosecutor of the Special Court for Sierra Leone.

The report contains proposals for the creation of a special tribunal for Ukraine by way of a resolution of the UN General Assembly, and reads in part:

The crime of aggression perpetrated by the Russian Federation must be dealt with under the rule of law. The invasion by the Russian Federation is … an international one. This aggression challenges the very idea of the UN Charter, and an appropriate response should be led by the UN to hold [Russian President Vladimir] Putin and his inner circle accountable for the invasion and successive criminality. The UN was created to deal with aggression of the kind that the Russian Federation has now committed. If the UN chooses to do little or nothing now, then the question arises: Why have a United Nations?

GAN notes that a significant majority of the UN General Assembly has condemned the invasion as well as the subsequent violations of international humanitarian law. In this light, the paper argues the General Assembly could circumvent Russia’s veto power in the UNSC by recommending with a majority of votes that the UN Secretary-General should enter into a bilateral treaty with the Government of Ukraine to establish a special tribunal with jurisdiction over the crime of aggression in Ukraine — similar to how the Special Court for Sierra Leone was created in the early aughts. The paper is careful to note that the work of such a tribunal should aim to enhance, not detract from, the ICC’s overarching jurisdiction over allegations of genocide, crimes against humanity, and war crimes.

The organization warns that a failure to act would have dangerous consequences:

Ultimately, whether or not by way of the creation of a special tribunal, justice for the civilian victims of Russia’s invasion will require the convergence of creative legal minds and political will.