On 24 February 2022, Russia commenced an unlawful invasion of Ukraine.
At the beginning of March 2022, approximately 40 States Parties referred the situation in the Ukraine to the ICC. After this joint referral from an unprecedented number of States, the ICC Chief Prosecutor opened an investigation. This investigation encompasses any allegations of war crimes, crimes against humanity or genocide on the territory of Ukraine. On 17 March 2023, the ICC issued arrest warrants for the Russian President Vladimir Putin and his so-called Commissioner for Children’s Rights, Maria Alekseyevna Lvova-Belova.
Due to the exclusion of the territory and nationals of Non-States Parties under Article 15bis(5) of the Rome Statute, the ICC is unable to extend the investigations to the crime of aggression. A referral by the UN Security Council could circumvent these jurisdictional restrictions but is unlikely due to the Russian veto.
Shortly after the Russian invasion, there was a call for establishing a special tribunal to hold those accountable who allegedly committed the crime of aggression against Ukraine (see here, here and here).
The need for establishing a special tribunal was acknowledged by parliaments of international organizations, such as the Parliamentary Assembly of the Council of Europe (see here and here) the Parliament of the European Union, and the Parliamentary Assembly of the NATO. National Parliaments of Czechia, Estonia, France, Latvia, Lithuania, the Netherlands and Poland followed and adopted resolutions supporting the establishment of a special tribunal (see here).
Several academic groups also supported the idea, with statements issued after events at Chatham House and the International Humanitarian Law Rountables at Lake Chautaqua.
Ukraine is currently advocating for the creation of a special tribunal. Ukrainian President Zelenskyy emphasized that Ukraine had prepared precise steps to establish such a tribunal. He argues that “the very fact of preparing indictments and issuing arrest warrants for those who planned and ordered the beginning of this aggression will be the most powerful signal to all other potential aggressors in the world that war is inevitably punished, and the guilty are held accountable; that the law is always valid and the law always prevails; and humanity is guaranteed to be protected.”
There is now a coalition (‘Core Group‘) on the creation of a Special Tribunal on the crime of aggression against Ukraine which includes representatives of over 35 States.
A special tribunal could be established on the basis of a multilateral treaty between interested States. It could also be established by using regional fora, such as the European Union or the Council of Europe. One may also proceed through the UN General Assembly which can recommend the creation of a special tribunal and provide the UN Secretary-General with a mandate to negotiate and conclude a treaty between the UN and Ukraine establishing a special tribunal for the crime of aggression (see here and here). A respective draft statute has been proposed by the Ukraine Task Force of the Global Accountability Network.
The more multilateral the establishment and international the design of the special tribunal, the easier it would be to address any legal and political challenges to it, including questions of personal immunity, legitimacy and impartiality.
Besides the proposals to establish a special tribunal, there are proposals to amend the ICC Statute (by the Parliamentarians for Global Action and the Global Institute for the Prevention of Aggression, see here and here), especially by deleting the carve out for Non-States Parties in Article 15bis(5) of the ICC Statute.
The crime of aggression is also punishable under international law as well as domestic law in Ukraine, Russia and Belarus.
The Russian use of armed force against Ukraine has been condemned as unlawful by several international organizations and experts groups, such as the UN General Assembly, the Global Institute for the Prevention of Aggression and the International Law Association Committee on the Use of Force.
Caveat: The site does not suggest that Ukraine is the only situation where the use of armed force is illegal.