All of these countries are members of the genocide conventon which means that even if not members of the ICC they have domestic laws criminalizing genocide. Th

All of these countries are members of the genocide conventon which means that even if not members of the ICC they have domestic laws criminalizing genocide. The great thing about the ICC is that if the perpetrator isn't a member they still have juridsiction if the victim country is (talking somewhat informally since the ICC prosecutes people not countries) If all else fails, the UNSC is allowed to "refer" situations (basically add juridsiction) to the ICC. They can also set up ad-hoc tribunials, like they did for Yugoslavia (which did send Ratko Mladić to jail for genocide). Some countries (e.g. Germany) also practise universal juridsiction for genocide. They have indeed sent people to jail for genocide even though it took place in a foreign country (e.g. Taha al-Jumailly). In fact, the ICC has only ever accused one person (Omar al-bashir) of genocide, and that person hasn't been tried because he is already in jail for other things. All succesful genocide prosecutions have been through other bodies, not the ICC. My main point though is i think genocide is the most illegal thing in the world. The ICC is part of the reason, but only part. There is of course always challenges enforcing stuff in failed states and war-torn regions, but I would challenge people to come up with something more criminalized than genocide.