Leading article: Russia's double game in Syria

As William Hague, Hillary Clinton and Alain Juppé headed to New York yesterday to press for a UN Security Council resolution on Syria, President Bashar al-Assad's tanks were in the suburbs of Damascus and the overall situation looked grim. More than 5,400 people have been killed since the uprising began last March, and the violence shows no sign of diminishing.

Against this background, efforts to secure a UN mandate for the Arab League peace plan that President Assad so mendaciously signed up to in December are urgent. The draft resolution calls for an end to violence on both sides of the conflict and requires President Assad to step aside in favour of a deputy charged with forming a government of national unity.

But however laudable the intention of this resolution, it is unlikely to convince Russia – an ally of both the current Damascus regime and its even bloodier predecessor. Russia has already refused to sign one UN resolution on Syria, and the latest scheme, backed by both Arab and Western states, is stronger still. Comments from Russia's Deputy Foreign Minister yesterday to the effect that the resolution is "a path to civil war" do not bode well.

Russia has its reasons. For Moscow, a UN resolution looks like a step on to the slippery slope that led to military intervention in Libya. Russia is also concerned about the instability that would follow President Assad's fall. Then there is the loss of face that would be the price of backing down.

Russia's supporters claim, meanwhile, that Moscow is pursuing a solution of its own. It is true that the Kremlin is attempting to broker peace talks between the Syrian government and the opposition, but it remains unclear whether such efforts are genuine or merely a ruse to pre-empt the UN. With one of the largest opposition groups apparently not invited, the latter explanation looks more likely.

It would, of course, be a mistake to conclude that, were it not for Russia's intransigence, President Assad's murderous regime would immediately fold, allowing Syria to join the Arab Spring. Sadly, the Assad regime is more entrenched than that. The opposition may not yet be sufficiently widespread to force him to consider his position.

But Russia does not get off the hook so easily. The future of Syria is a complex matter. The condemnation of a government that sends tanks against its own people, however, is not. That Moscow continues actively to abet the Assad regime – selling Damascus $550m-worth of fighter jets, for example – is shameful. If Russia cannot support the Arab League peace plan out of common humanity, it should, at the very least, hold back its veto.