For example, the UN. The current fit of complete lawlessness seems to be de rigueur within these institutions at the mo.
My impression is that all other international players would like to have a legal framework of international laws that works.
Rather than re-inventing the wheel, it seems sensible to slowly chip at it until the rogue states start seeing that it is in their interest to have this framework in place.
Perhaps ignoring OPCW rulings temporarily might be the way to go, until this mess is sorted out.