As part of a conference organised by the International Bar Association (IBA), the team behind Asymmetrical Haircuts: your international justice podcast recorded an interview with Dr Mark Ellis, Executive Director of the IBA. The conversation focused on the practical modalities of the future Special Tribunal for the Crime of Aggression against Ukraine and the key legal and political challenges that this mechanism is expected to face.

In absentia proceedings as a potential tool of the Tribunal

One of the central questions discussed in the episode concerned the Tribunal’s ability to proceed when a state is unable to arrest senior officials suspected of committing the crime of aggression. According to Dr Mark Ellis, in such situations in absentia proceedings may become a viable option. This refers to cases in which an accused person is unable or unwilling to appear before the court, while the proceedings may nevertheless continue in their absence.

Although this format is not typical for most international criminal jurisdictions, it is employed in certain legal systems and is likely to become part of the Tribunal’s procedural toolkit.

Scope of application and the question of immunities

Dr Ellis emphasised that the possibility of conducting in absentia proceedings has its legal limits. In particular, under the rules of international law on immunities, the sitting President of the Russian Federation, Vladimir Putin, cannot be brought before such a Tribunal while he remains in office. This remains one of the most complex issues in designing the Tribunal’s mandate.

The expert also noted that states participating in negotiations on the establishment of the Special Tribunal — a process in which he has been directly involved — hold differing views on whether and how the immunities of the highest-ranking officials may be limited. Some governments advocate for the broadest possible mandate, while others take a more cautious approach due to the potential precedential implications.

Political context and the risks associated with timing

Another issue raised during the discussion was whether the Tribunal can be established and begin operating before its creation becomes vulnerable to political pressures — for example, in the context of possible “peace negotiations” or broader geopolitical compromises. According to Dr Ellis, this is one of the key challenges facing the international coalition working on the Tribunal’s design.