The following guest post was written by Volodymyr Pylypenko. Volodymyr holds a PhD in Law and is an Associate Professor in the International Relations Department of Lviv University of Business and Law, Ukraine. His previous post for JiC, ‘The View from Ukraine: Why a New International Criminal Tribunal to Prosecute Russian Aggression is Needed’ is available here.

Modern international law knows several relevant precedents. International tribunals became effective tools to punish persons guilty of the most serious international crimes of the 20th century, including the crime of aggression. The International Military Tribunals in Nuremberg and Tokyo, which were established after the Second World War recognized in their verdicts the planning, preparation, initiation and/or the waging of an aggressive war as an international crime. Accordingly, an ad hoc international criminal tribunal (ICT), with the power to prosecute senior Russian officials with the planning, preparing, and waging of aggressive war in Ukraine is plausible and legitimate. That is also the view of states, including The Netherlands, Estonia, Latvia, and Lithuania, as well as some international organizations such as the European Union (EU) and the Counsel of Europe, which have discussed the need to create such a tribunal to punish Russian officials for the crime of aggression and other international crimes.
A week ago, the ICC issued an arrest warrants against Putin and Russian Commissioner of Children’s Rights, charging them for serious war crimes such as unlawful deportation of Ukrainian children. Other charges for war crimes in Ukraine are like to still appear while the ICC Prosecutor meticulously examines Russian atrocities in Ukraine. Meanwhile, the ICC does not have a jurisdiction to accuse Putin and hold him to account for the crime of aggression he committed against Ukraine. As I mentioned in my previous blog piece, I believe the establishment of a separate, international ad hoc tribunal is the best option to prosecute Russian aggression. In this blog I discuss possible options concerning the nature and the manner of establishing such a tribunal.
The sooner the main stakeholders agree on a unified strategy over the organization and functioning of this ICT and define a legal basis for its creation, the sooner accountability for aggression will follow. However, there are still some ‘pitfalls’ connected to the model of the future tribunal. In what follows, I briefly assess three possible options.
Creating a tribunal through treaty between the states
An ICT can be created on the basis of an international treaty between states. Ukraine, as the state that has directly suffered the damage caused by Russian aggression, should be a mandatory participant in such a treaty. Under the same treaty, the parties should approve the ICT’s Statute, which will determine its procedural and substantive elements. The best precedent for this mechanism is, in my view, the well-known Nuremberg Tribunal, which was established on the basis of an agreement between the USSR, the United States, Great Britain and France with 19 other countries joining afterwards.
Opponents of this model appeal to the unlikelihood that the aggressor state and persons who may end up on its bench will recognize and accept its jurisdiction. The ICT’s jurisdiction and its ‘international legitimacy’ could also be contested given the small number of states participating in the creation of its founding treaty. For instance, states that are not interested in holding Russian leaders accountable may question its legitimacy. In addition, the ICT would be most effective only after the end of the war and Ukraine’s victory, as it would be a ‘victors’ court’ like the Nuremberg Tribunal. Regardless, such a tribunal may be gaining traction if the Core group of states, which consists now of 33 members and still growing, would decide to establish an ad hoc criminal mechanism by a multilateral treaty.
Creating a tribunal using the legal capability of international organizations
The ICT can also be established as an ad hoc tribunal based on a UN Security Council resolution. This mechanism was used to establish the tribunals for the former Yugoslavia and Rwanda. Although these tribunals were not charged with prosecuting the crime of aggression, they provided modern international criminal law with significant practice in the investigation of war crimes and genocide.
However, Article 24 of the UN Charter undermines the success of this option, as it provides that the responsibility for maintaining international peace and security rests with the Security Council, and related decisions must receive unanimous support from all five permanent members to be adopted. Apart from Russia, which would never support the decision to establish the ICT against its own political leadership, China, which is usually in solidarity with Russia, will also likely veto such resolution. Thus, the adoption of the corresponding resolution is practically impossible. Although Russia could be eliminated from participating in the vote per Article 27 of the UN Charter as a ‘participant in the conflict’ or be deprived of its status as a permanent member of the Security Council as an illegitimate entity, none of these options have sufficient support.
That said, the ICT could also be established through an international treaty between Ukraine and the UN General Assembly. According to the Guardian, the draft of the Resolution concerning this issue and a draft Statute are already being circulated among the members of the UN General Assembly. Notably, representatives from Ukraine’s Presidential Office recently stated that such mechanism was possible.
If the UN route does not work, however, international organizations could lead the creation of the ICT. In addition to the UN, European organizations – the Council of Europe and the EU – could lead this effort. As previously noted, these organizations already condemned Russian aggression and other international crimes committed in Ukraine and have also called for the creation of an ICT.
Creating a “hybrid” tribunal
Another option promoted by scholars, lawyers, and the UK (as well as other states) is the establishment of a “hybrid” tribunal based on international and Ukrainian Law. Proponents refer to the Special Court for Sierra Leone and the Extraordinary Chambers in the Courts of Cambodia as possible examples; both were set up through agreements between the respective countries and the UN.
This choice seems doubtful. I believe that Ukrainian Constitution forbids the creation of any extraordinary or special courts in Ukraine. Some may try to argue that a future hybrid tribunal will neither be extraordinary nor a special court. Nonetheless, it is imperative that the creation of this body respects the Ukrainian Constitution. In fact, the 2001 decision of the Constitutional Court of Ukraine, which found that the complimentary jurisdiction of the ICC conflicts with the Ukrainian Constitution has blocked its ratification for a decades. Despite Constitutional amendments of 2016 which brought the Constitution of Ukraine into the line of the Rome Treaty the ratification is still to come. Of course, this verdict of the Constitutional Court of Ukraine concerns only a Rome Treaty of ICC and cannot affect any future hybrid tribunal if created. But its mere existence in Ukrainian law system may be a precedent to challenge a jurisdiction and legal capacity of a future hybrid court. Accordingly, creating a hybrid tribunal would likely require a constitutional amendment. However, the Parliament of Ukraine is not authorized to amend the Constitution when the country is under martial law.
In addition, some scholars correctly note that a “hybrid” tribunal may be faced with the immunity of high ranked Russian and Belorussian officials accountable for the full scale aggression. The office of the Prosecutor General of Ukraine as well as Presidential Office of Ukraine are on the same page regarding the set-up of “hybrid” tribunal. Ukrainian officials stress that such hybrid model contains the risks of narrowing the legal assessment of ongoing aggression to the level of “interstate conflict.”
Finally, neither a ‘hybrid’ tribunal nor the examples of such courts are relevant options given that the conflicts in Sierra Leone and Cambodia were of non-international nature. Here, we have an international armed conflict and a violation of the UN Charter by a member of the Security Council. The world needs the widest territorially international institution of responsibility for aggression with the highest level of legitimacy and recognition.
Different approaches to set up the ICT should be without prejudice to the irreplaceability of its creation and activity. The choice of a model for the establishment of a special ICT is extremely important for the future conviction of persons guilty of planning, preparing, and waging an aggressive war against Ukraine. A future tribunal must have proper international recognition to guarantee the criminal responsibility of all responsible for the aggression on Ukraine. Ensuring the principle of the inevitability of punishment for international crimes is important not only for Ukraine, but also for the whole world to prevent such atrocities in the future. It will also be a good example and warning for those who still think that the most serious international crimes can go unpunishable.
Considering the scale and gravity of the crimes committed by Russia and their consequences for Ukraine and for the rest of the world, the establishment of an ICT through a treaty between states is the best option under the international law, followed by the option of creating an ICT through a treaty with the international organization. This is what the Ukrainian people and officials want, for the reasons I have outlined as well as other. In my view, a hybrid mechanism would diminish the atrocities Russians have committed and that Ukrainians have suffered. Perhaps we Ukrainians are emotional or biased on this question but we deserve it: we want a new Nuremberg to punish Putin and not a hybrid tribunal. This is what Ukrainians are waiting for.
Important post indeed.
Yet, one major issue, must be raised here:
You claim, and justifiably so (apparently) that the ICC, can’t deal with or punish for the crime of aggression in that case of Russia and Putin. Ok. Yet, an arrest warrant has been issued. What does it mean:
It means, that the immunity of Putin, has been actually removed. To what extent we don’t know ! (we can’t know, for Rome statute, doesn’t clarify it). But removed. But, you don’t prove here, that such removal of immunity, concerns only the ICC or vis a vis ICC as a court, and solely the ICC. Why not to claim, that such removal of immunity, makes it possible, for Ukraine or hybrid court, to try Putin, for the crime of aggression we couldn’t understand.
I quote for example from very recommended article in EJIL:Talk! (Written by Miguel Lemos):
” To argue that states can deploy all forceful and non-forceful measures necessary to repel aggression, except the measure[s] of [issuing an arrest warrant, arresting or simply] prosecuting the sitting head of state who is perpetrating the very act of aggression, is pure nonsense.”
Here:
https://www.ejiltalk.org/the-law-of-immunity-and-the-prosecution-of-the-head-of-state-of-the-russian-federation-for-international-crimes-in-the-war-against-ukraine/
So, theoretically, if Putin, is present in Ukraine, are you telling us, that Ukraine or hybrid court, wouldn’t be able to arrest him and indict him ? Let alone, after removal of his immunity done already by the ICC ?
Maybe you think that not. OK. But we couldn’t read, any coherent and plausible reasoning in that post for that issue with all due respect.
Thanks