Leave it to Russians and the society will suffer in the long run. Leave it to Assad and the society suffers already as it is. Leave to the rival fractions and they are too extreme.
You cannot leave it to neither of them. Yet you cannot stay idle and not do something about it neither for Assad is butchering his own civilian people.
It seems the only issue worth engaging here is the society in Syria. If all these powers were to go away the power in the vacuum could be won with elections instead.