Russia vetoed it because Syria are one of their strongest allies, buy a lot of weapons from them, and contain one of their only military bases outside of their own borders. They originally proposed ammendments to the resolution to prevent Western powers supplying weapons and military assistance to what they percieve as terrorists within syria. These ammendments were rejected by the USA who pushed for the restrictions to be applied only to one side (the Syrian Government) of the fighting in Syria. No surprise they couldn’t agree.
Although we are being led by our media to view Russia and China as a single threat here, Chinese opinion is more concerned with the previous NATO abuse of UN mandates in Lybia, Iraq, and Afganistan.
In March, China abstained from a council vote that authorised western military intervention in Libya. That resolution became the basis for a Nato air campaign that led to the overthrow of Muammar Gaddafi. Beijing and Moscow regarded the campaign as going beyond the resolution.
“Libya offers a negative case study. Nato abused the security council resolution about establishing a no-fly zone and directly provided firepower assistance to one side in the Libyan war,” said the People’s Daily.
It cited Iraq and Afghanistan in its case against the Syria resolution. “[These] calamities of Iraq and Afghanistan should be ample to wipe clear the world’s eyes. Forceful prevention of a humanitarian disaster sounds filled with a sense of justice and responsibility.
“But are not the unstoppable attacks and explosions over a decade after regime change a humanitarian disaster?”
from :http://www.guardian.co.uk/world/2012/feb/06/china-syria-veto-peoples-daily