"The world needs to be made aware of the atrocities that Russian President Vladimir Putin has ordered in Ukraine. There are currently three ways under international law that Putin’s actions can be subjected to global scrutiny, and these can be complemented with a new body focused on the specific crime of aggression."
https://www.project-syndicate.org/commentary/tribunal-putin-war-crimes-by-gordon-brown-et-al-2022-03
https://www.project-syndicate.org/commentary/tribunal-putin-war-crimes-by-gordon-brown-et-al-2022-03