Russia has its own fish to fry in Syria, not least the fact that the Syrian port of Tartus is home to Russia's only Mediterranean naval base. They also have a profitable arms trade as well as historical ties to the Assad family - a holdover from the Soviet days.

But it is clear that their veto of a UN Security Council resolution backing an Arab League plan that would have Assad voluntarily giving up power to his Vice President while an interim government worked toward democratic elections has emboldened the dictator. After 400 or more civilians were killed over the weekend in the flashpoint city of Homs, Assad's forces continued their machine gun and mortar barrage on Monday killing another 95 according to activists.

BBC:

Visiting Syria, Mr Lavrov said Damascus was ready for a larger Arab League mission to monitor the plan, which the West has urged Syria to accept.

Crowds gave Mr Lavrov a hero's welcome. His visit comes after Russia and China vetoed a UN resolution.

Government forces are continuing a fierce assault on rebels in Homs.

Thousands waved Syrian and Russian flags as Mr Lavrov's convoy moved through Damascus. He later held talks with President Bashar al-Assad.

Crowds of people were out in Damascus as Sergei Lavrov's convoy arrived

The BBC's Paul Wood - one of the only foreign reporters in Homs - says the Syrian army resumed mortar attacks and heavy machine-gun fire after daybreak.

He says Russian-made tanks have been seen close to the city centre, but these is no sign so far of the ground assault feared by many residents.

Both Russia and China are going to have blood on their hands before this nightmare is over. They are already damaging their relationships in the Arab world and further obstructionism is likely to cause a backlash that would hurt their commercial and military ties in the region.

But Assad is the linchpin of Russia's Middle East strategy and they can't afford to wait and see if regime change would alter that equation.