The protracted violence and deaths in Syria has been a cause for concern, with the Security Council also having condemned it in the past. However, while voting on adoption of a resolution that condemned “grave and systematic human rights violations” in Syria and entailed threat of measures under the U.N. Charter against Syria, both Russia and China vetoed it [much to the exasperation of the US (calling it a 'ruse') and European nations, who pushed for the resolution in the first place].
Russia’s reasons for the veto were that although they did not support the Syrian regime, the resolution would make onerous a peaceful resolution of the dispute (“ Russia does not agree with the unilateral accusatory bias against Damascus.”). Whereas China believed the resolution will only complicate the matter. (see here).
Mark Kersten writes that the veto was not surprising as the situation surrounding Syria is much different that what happened with Libya. Also, that the expectation that a new norm of international politics for intervention to protect human lives and human rights would take shape after the unanimous resolution against Libya was quite far-fetched. In fact, that the West was rebuffed by China and Russia was a direct concomitant of what happened after the Libyan resolution.
Although consensus in the international community is hard to come by, in matters that require concerted action, political calculations play a major role. The major powers will stand united on pressing matters only if their interests are served and accommodated. What is questionable is the organized hypocrisy behind international considerations – which is a not a new phenomenon.