this is why you dont assassinate someone on foreign soil
unfortunately i cant think of a way for these nations to punish russia over this. its clear russia doesnt give a forget atm about the views of us/uk and actually seems to prefer being viewed negatively, as long as it doesnt face serious permanent repercussions. they seem perfectly content drumming up conflict, whether its between them and others, or just between others.
it seems like this will just blow over like the
poisoning of Alexander Litvinenko and nobody will really care after a few years