One: Syria is already in a full civil war and it will end in one of two ways: partition or genocide of the Alawi, Shi'ites and Christians and maybe Druze of Lebanon and Syria.
Two: The Russians have no reason to support the Sunni dictators taking over Syria and Iran.
Three: If the Saudis are so concerned about dead civilians, why don't they send their own armies? Why do American and British soldiers have to die for the Saudis? Just so that American leaders can go to cocktail parties?