24 February 2023

What can(’t) international criminal justice deliver for Ukraine?

One year ago, Russia began its full-scale invasion of Ukraine, committing an act of aggression in violation of the UN Charter. Many more incidents of international crimes followed, adding to an already large number of unaddressed crimes going back to 2014 (see here for the Ukraine Prosecutor General’s Office statistics).

The reaction by European and North American states focused heavily on international criminal law to address and sanction violations of international humanitarian law and human rights law. In addition, and most visibly, there is an ongoing discussion about how to prosecute the crime of aggression, though one hears less frequently about the progress being made with regard to investigations into the other three core crimes under international law: war crimes, crimes against humanity and genocide.

While investigations are underway, the failures to pursue accountability for international crimes committed by Russia in the past still need to be addressed in this context. The international criminal justice sector, along with many governments, bear responsibility for their failures and selectivity in bringing high-level Russian superiors to justice prior to February 2022. In light of all this, conclusions must also be reached in the debate about an international special tribunal for the crime of aggression, which would perpetuate double standards in the implementation of international justice and thus undermine its legitimacy. Other pathways to prosecute the crime of aggression do exist.

The status of international investigations one year into the conflict

The initial weeks after the invasion were filled with almost daily announcements that another prosecutor’s office had opened investigations into international crimes under the principle of universal jurisdiction (as one would wish for other conflict situations as well). This came in addition to states’ referrals to the International Criminal Court (“ICC”), which enabled the Office of the Prosecutor to start its investigation early on.

However, since then, authorities have been working in silence. It is less well known how the massive resources provided are being spent, what the targets of investigations are, and how states coordinate. This is no surprise, given the necessarily confidential nature of investigative work, especially at the outset of an investigation. Another open question concerns the relation of international investigations to domestic procedures in Ukraine, which have been criticized for failing international standards of prosecutions.

The basic approach of war crimes units acting under the principle of universal jurisdiction is to secure evidence that is directly accessible to them. So, we can assume that in countries like Germany, Sweden, Poland and many others, a significant number of witness statements have been formally secured through interviews by the competent investigating authorities. In addition, war crimes units will likely have received additional evidence from witnesses, such as pictures, videos and documents which they brought with them. Furthermore, open-source evidence is also available to war crimes units – as it is to everyone else – which they, along with NGOs, will have likely captured.

The next step, which has most likely not yet been taken by every war crimes unit, is to further select and investigate individual or systematic incidents, along with chains of command. This is where things start to get interesting, as these selections contain the strategic elements that indicate which kinds of cases and what level of perpetrator we could one day see in court – or at least served with an arrest warrant.

This strategic selection process needs coordination, for example by Eurojust’s EU Genocide Network, or through the joint investigation team composed of several states and the ICC, along with domestic Ukrainian authorities, victims’ lawyers and NGOs. For war crimes units, it is important to know who else is investigating a particular individual case, a pattern of crimes, a specific location, such as Bucha, Kherson or Izyum, or certain suspects in key positions within the chain of command. Similarly, it would be important for NGOs to know these things as well, as they have their own strategic case selection process, and focus their efforts on analyzing patterns of crime and command chains, as well as on identifying where evidence is located for further investigations (see here for ECCHR`s web dossier). The EU Genocide Network has begun to function as bridge in this regard, facilitating some direct exchange between NGOs and war crimes units.

A year after the full-scale invasion, we know that a lot of resources have been spent to secure evidence and to build cases at many levels. However, it is too early to know which cases will be prioritized by the war crimes units and the Office of the Prosecutor of the International Criminal Court. The risk exists that, for legal or evidential reasons, crimes such as those against the environment, airstrikes or conflict-related sexual violence, continue to remain unaccounted for. Even if progress is being made, it is a balancing act to communicate this without revealing too much about the targets, as arrest warrants might be sealed for good reason.

The responsibility of the criminal justice sector

When looking at the status quo, one should not forget that international crimes have been committed in Ukraine since 2014. Moreover, Russian troops have been responsible for perpetrating international crimes over a much longer period of time and in many more places than just Ukraine, from Chechnya to Georgia to Syria. Similar observations can be made about the activities of Wagner group members and Chechen security forces. Some perpetrators might reappear in current Ukraine investigations, providing the chance to prosecute them for crimes committed in other conflicts as well.

Especially with regard to Chechnya, many opportunities were missed, as perpetrators traveled rather freely to the EU. Members of Chechen leader Kadyrov’s inner circle even spent time at mixed martial arts fight events in Europe, for example, and posted pictures of their trips online (which had been reported to war crimes units at the time). Others came to carry out abductions of dissidents and return them to Chechnya, while in certain cases, some even perpetrated killings in the middle of European capitals, such as Vienna or Berlin. The perpetrators of the latter cases were prosecuted, but it remains unlikely that significant steps have been taken against those who ordered the assassinations. Over the years, it appeared as though Europe had not only become dependent on Russian energy, but also had a policy of avoiding the investigation of Russian or Chechen perpetrators, except for the henchmen who were caught after fatal incidents. The same policy seemed to be in place when it came to Russian crimes in Syria or even in Ukraine prior to 2022.

Regarding the latter situation, the focus was on the ICC, as it had jurisdiction after two ad hoc declarations had been made by Ukraine in 2014 and 2015. After years of preliminary examinations, the Office of the Prosecutor of the International Criminal Court decided in 2020 to open investigations, while highlighting that more resources would be needed to do so.

Something new is needed? The debate on prosecuting aggression

The crime of aggression is a core crime under the Rome Statute, which criminalizes violations of one of the pillars of the UN Charter, the prohibition of the use of force. Since 2018, the ICC has the power to prosecute it. However, there is an exception with regard to this crime that does not pertain to the three other core crimes, as Article 15 bis (5) of the Rome Statute requires that the aggressor state also needs to be a party to the Rome Statute (or a UN Security Council referral, which is not a viable option in this situation) for the ICC to exercise its jurisdiction. Realistically, only after a regime change would an aggressor state potentially ratify the Rome Statute. On the other hand, technically, it would be quite easy to change the Statute within a matter of months, to delete this provision, and for the Office of the Prosecutor to apply it retroactively. As a procedural change, this would be possible, as the crime of aggression has been defined in international law long before 2022, is under the ICC`s jurisdiction since 2018 (as required by Art. 22 (1) of the Rome Statute) and Russian leadership was in a position to know that they were committing a crime under international law. It all depends on the political will of the 123 ICC state parties.

There’s been much discussion about creating a special tribunal under international law through a majority vote of the UN General Assembly (or other models), with the possibility of in absentia trials. Without going into the details of what this could look like – there is no shortage of blogs and articles which do so – the legitimacy of any new court created under international law would likely be fragile at best, if not non-existent, even if the UN General Assembly were to endorse it. Such a court would go down in history as a special court created for one specific situation, and not as one applicable to others, especially if it were to include in absentia trials at a time when a permanent international criminal court exists. The only way around the legitimacy question, particularly for states which themselves became victims of acts of aggression by more powerful states in the past – and this list is rather long – would be to find a majority in the ICC Assembly of States Parties to change the Rome Statute. Instead of a one-time-only special court, this would also equip the ICC with the jurisdiction to address similar future situations of crimes of aggression. Only such a step would stabilize the global legal order, instead of further fragmenting it by following the will of the more powerful states.

Certainly, Ukraine also has the right to prosecute the crime of aggression. However, even though Ukrainian law includes the crime of aggression, it falls short of the Rome Statute definition, especially of being a leadership crime. In addition, it would nevertheless be understandable if, considering the current circumstances of ongoing aggression against its territory, Ukraine itself is not in a position to prosecute the crime before its domestic courts in an independent and impartial manner. Thus, to support the country internationally, a hybrid Ukrainian-internationalized institution would be another option that bears legitimacy while avoiding double standards. This would be even more so the case, if all international core crimes would be included in such an institution, composed of international and Ukrainian staff. The fact that Russian leadership would enjoy immunity before a national court, demonstrates, on the other hand, the urgency to reform the Rome Statute.


We’ve come a long way, with many missed opportunities before 2022. There is a chance now to set a precedent for strengthening international criminal justice, domestic justice and international cooperation without delegitimizing it through the creation of special courts. There are many more conflicts that would benefit tremendously if international criminal justice progresses in an equal manner that is applicable to all situations.

SUGGESTED CITATION  Schüller, Andreas: What can(’t) international criminal justice deliver for Ukraine?, VerfBlog, 2023/2/24, https://verfassungsblog.de/justice-ukraine/, DOI: 10.17176/20230224-185251-0.

One Comment

  1. Edward Fri 24 Feb 2023 at 10:24 - Reply

    Dear Andreas,

    Many thanks for your blog post.

    However, I am a little puzzled since your post reads as if crimes have been committed for which merely criminal conviction is outstanding.

    While scholars (and other legal practitioners and actors) agree that laws prohibiting aggression have been violated, in my humble opinion international legal scholars should be very careful when it comes to asserting any claims with respect to supposedly evident and manifest *crimes* since this would run counter to the principle (also applicable in international criminal law) of innocent until proven guilty. As you know such guilt has to be determined by a court and not by scholars.

    This might be a good opportunity to remind oneself that Laurent Gbagbo, while charged with heinous crimes, was acquitted.


Leave A Comment


1. We welcome your comments but you do so as our guest. Please note that we will exercise our property rights to make sure that Verfassungsblog remains a safe and attractive place for everyone. Your comment will not appear immediately but will be moderated by us. Just as with posts, we make a choice. That means not all submitted comments will be published.

2. We expect comments to be matter-of-fact, on-topic and free of sarcasm, innuendo and ad personam arguments.

3. Racist, sexist and otherwise discriminatory comments will not be published.

4. Comments under pseudonym are allowed but a valid email address is obligatory. The use of more than one pseudonym is not allowed.

Explore posts related to this:
International Criminal Court, Russian War against Ukraine, Ukraine, Vladimir Putin, criminal justice

Other posts about this region: