As Syrian army tanks mass around Homs and its artillery pounds Sunni districts of the city, Syria is slipping into the first stages of a sectarian civil war. This conflict could be as bloody as anything seen in Iraq between 2006 and 2007 or as long as the civil war in Lebanon (1975-90). The two words that best describe the current process in Syria are "Lebanisation" and "militarisation"; neither bodes well for Syria's people.

Short of a serious split in the Syrian army, the opposition forces' best chance of success is to lure outside powers into such a venture. They want a repeat performance of what happened in Libya. The rag-tag militiamen who finally captured Tripoli would have been beaten in a few days without close air support from Nato. But Syria is not Libya, its powerful armed forces have not yet disintegrated, and, most importantly, it is not isolated internationally to anything like the same degree as Gaddafi was.

By any realistic calculation, Assad might well last into 2014. Glib references to his isolation are exaggerated. The vote on 4 February in the UN Security Council condemning him and asking him to turn over power to his deputy was vetoed by Russia and China.