I think there is more to this than we read in the newspapers, I honestly believe Russia is trying to stop another NATO intervention like the Libyan civil war, what a disaster that was....
Do you think the UN really cares about the Syrian citizens? when NATO went to Libya they caused more harm than good and actually created more violence than even Gaddafi.
There could be a bit of truth in it though, maybe Russia and China believe they could be the next victims of a NATO "Humanitarian" mission, maybe that is why they arent so eager to intervene with Syria's internal conflicts.