Ця стаття також доступна українською мовою тут.

Discussions to create a Special Tribunal on the crime of aggression against Ukraine are proceeding rapidly. On Jan. 19, the European Parliament adopted a new resolution on the establishment of a tribunal, which underlined that:

[T]he special international tribunal must have jurisdiction to investigate Vladimir Putin and the political and military leadership of the Russian Federation, but also Aliaksandr Lukashenka and the political and military leadership in Belarus.

The same week, both Germany and the United Kingdom, publicly expressed support for a hybrid aggression tribunal integrated into Ukraine’s national justice system.

A few days later, on Jan. 26, the Parliamentary Assembly of the Council of Europe adopted a resolution calling for the creation of a Special Tribunal with a statute which would:

[C]learly state that personal immunities would not apply to incumbent State officials, in line with the practice of other international criminal tribunals, and that functional immunities would in any event not be applicable to the crime of aggression

Thus, one important consideration in the ability of any Special Tribunal to try senior members of the Russian and Belarusian leadership is the question of immunities under international law. There is growing commentary on the application or non-application of immunities before a Special Tribunal (for example, see this Just Security post by Astrid Reisinger Coracini and Jennifer Trahan and this publication by The Netherlands’ Advisory Committee on Public International Law).

The Open Society Justice Initiative and our colleagues at the International Renaissance Foundation have published an analysis of how personal and functional immunities could apply to prosecutions before a Special Tribunal.

Our analysis highlights that the ability to try senior Russian officials for the crime of aggression will depend on the specific nature of the tribunal. In particular, whether the Special Tribunal constitutes an international court or tribunal will substantially determine its authority to deny the personal immunity of President Putin and a small number of other high-level Russian officials.

What Makes a Court or Tribunal “International” for Personal Immunity?

Personal immunity, or immunity ratione personae, is a status-based immunity which applies to a small number of high-level State officials because of their office, specifically the head of State, head of government and minister of foreign affairs.

The Appeals Chamber of the International Criminal Court (ICC) and the Appeal Chamber of the Special Court for Sierra Leone (SCSL) both found that a head of State does not have personal immunity before an international tribunal (ICC, Al-Bashir, Judgment in the Jordan Referral, paras. 113-117; SCSL, Charles Taylor Decision on Immunity, paras. 52-53). The two Appeals Chambers emphasized that international courts and domestic courts differed in nature. In particular, both courts stressed that the par in parem principle, according to which one sovereign cannot exercise jurisdiction over another sovereign, does not apply to international courts. According to the ICC Appeals Chamber, international courts “act on behalf of the international community as a whole,” they “do not act on behalf of a particular State or States” (para. 115). Thus, the first characteristic of an international court able to decline to recognize the personal immunity of a head of State – and by analogy of a head of government, and minister of foreign affairs – is that it acts on behalf of the international community.

Acting on behalf of the international community is a necessary, but, we argue, not sufficient criterion of assessing whether a court is international for these purposes. Arguably, any domestic court acts on behalf of the international community whenever it properly adjudicates international crimes. However, this alone does not enable such a court to overcome the personal immunity of high-level foreign officials. The second critical characteristic of an international court is that it exercises jurisdiction on behalf of multiple States. In explaining its finding that the SCSL was an international court, the SCSL Appeals Chamber emphasized that the SCSL “is not a national court of Sierra Leone and is not part of the judicial system of Sierra Leone exercising judicial powers of Sierra Leone” (para. 40). While an international court must exercise jurisdiction on behalf of a multiplicity of States, this leaves open important questions, which we discuss further in our analysis, notably the number of States on whose behalf the international court must exercise its jurisdiction.

Different Models for a Special Tribunal

Our paper considers four different models of a Special Tribunal established:

  1. Following a United Nations (U.N.) General Assembly resolution calling either for the U.N. Secretary-General to conclude an agreement between the U.N. and Ukraine or for a regional organization, the European Union (EU) and/or the Council of Europe, and Ukraine to conclude an agreement to establish the tribunal (General Assembly Model)
  2. Through an agreement between Ukraine and the European Union and/or the Council of Europe in the absence of a UNGA resolution (Fully Regional Model)
  3. Through a multilateral treaty between Ukraine and other States (Multilateral Model)
  4. As a domestic but internationalized Ukrainian court (Internationalized Model)

Our assessment is that a Special Tribunal which is endorsed by the General Assembly has the strongest claim to the status of being recognized as an international tribunal because of the broad membership of the U.N., whether that Tribunal would be established by agreement between Ukraine and the U.N., the EU, or the Council of Europe. One outstanding question here is the number of States which would have to support the U.N. General Assembly endorsing the Special Tribunal. Article 18 of the U.N. Charter distinguishes between “important questions” (decided by a majority of members present and voting) and “other questions” (decided by a two-thirds majority of the members present and voting).

The Fully Regional Model presents some claim to the status of being an international tribunal. The Council of Europe has a larger membership than the EU with 46 Member States. We consider that a unanimous endorsement by the Council of Europe would support the claim that the Special Tribunal would be acting on behalf not of Ukraine, but of the entire region.

The Multilateral Model raises again the question of the number of States that would have to ratify the agreement establishing the Special Tribunal for personal immunity not to apply. Personal immunity would likely continue to apply if the Special Tribunal were established through a treaty signed by Ukraine and a small number of States.

The Internationalized Model could take many different forms, in terms of staffing, location, funding, and type of law, among other considerations. A Special Tribunal exercising Ukrainian jurisdiction which is not endorsed by the General Assembly, a regional organization, or many States, would not be international in nature and would likely be restricted by the personal immunity of senior Russian officials. We acknowledge, however, that different arguments have been advanced suggesting that Ukraine may deny personal immunity based on a right of self-defense (e.g., by Dapo Akandeat 41:20), under international humanitarian law to target or detain the commander-in-chief of the opposing armed forces (e.g., by Tom Dannenbaum on Just Security or Miguel Lemos, or as a countermeasure (e.g. by Anton Moiseienko).

What about Functional Immunity?

Functional immunity, or immunity ratione materiae, is a conduct-based immunity which applies with respect to acts performed in an official capacity. Our analysis suggests two alternative ways to consider the application of functional immunity before a Special Tribunal.

First, one can argue that an exception to functional immunity exists for international crimes and that this exception extends to the crime of aggression. The Nuremberg Tribunal enshrined the principle that a person’s official position does not exempt them from individual criminal responsibility (as articulated in Principle III of the Principles recognized in the Charter and Judgment of the Nuremberg Tribunal). According to this first line of reasoning, the status of the Special Tribunal as an international tribunal is irrelevant: officials accused of aggression would not enjoy functional immunity before any court, whether international or national. However, some have questioned the existence of an exception to functional immunity for the crime of aggression. The International Law Commission adopted the position in Draft Article 7 on the Immunity of State officials from foreign criminal jurisdiction that the exception to functional immunity only applies in respect of certain international crimes. Crucially, the ILC did not include the crime of aggression on the list of international crimes, which suggests that functional immunity could continue to apply in respect of the crime of aggression. Thus, proceedings against Russian officials for the crime of aggression may face challenges if they rely on an exception to functional immunity.

Second, one can argue that, irrespective of the existence of an exception to functional immunity for the crime of aggression, functional immunity would not apply before a Special Tribunal which amounts to an international tribunal. The decisions of the ICC and SCSL Appeals Chambers both related to the (non-)application of personal immunity, rather than functional immunity, before international courts. However, the reasoning of the ICC Appeals Chamber is also helpful when considering whether functional immunity would apply before an international court. Indeed, the par in parem principle would not apply where a court that is international passes judgment on the conduct of a State official performed in an official capacity. The International Court of Justice in the Arrest Warrant case noted that a former foreign minister, who only benefits from functional immunity and no longer personal immunity, could be prosecuted “before certain international courts” (Judgment, para. 61). Thus, functional immunity would not prevent prosecutions before a Special Tribunal which amounts to an international tribunal.


Diplomatic discussions now underway on the merits of supporting a Special Tribunal will have to weigh the relative merits of different models and consider which have stronger claims to the status of an international tribunal before which immunities would not apply. As the full-scale Russian invasion approaches its first anniversary, inaction is not an option.

IMAGE: The European Parliament held a plenary session on January 17, 2023 and discussed the establishment of a tribunal on the crime of aggression against Ukraine. (Photo via European Parliament)