The establishment of a Special Tribunal to Investigate the Crimes of Aggression against Ukraine with Mykola Gnatovskyy

How and why did the idea of calling for the establishment of a special tribunal to investigate the crimes of aggression against Ukraine come up in the first place? Why was it necessary to call for the establishment of a new International Criminal Court when there is one already in The Hague? Why can the International Criminal Court not investigate Russia for crimes of aggression? Under what conditions could any newly established special court successfully prosecute anyone from the highest echelons of the current Russian regime? What is the broader symbolic significance of taking such initiatives today, initiatives which may not immediately be implemented, but at least bring about a larger public discussion about the role of international law in armed conflict?