AMMAN (Reuters) – Syrian government forces backed by foreign Shi’ite Muslim militia advanced on rebels in the northern city of Aleppo on Tuesday, bent on recapturing districts from opposition brigades weakened by infighting, activists said. They said that rebels saw the threat of President Bashar al-Assad wresting back Aleppo, Syria’s former commercial hub and once most populous city, as so grave that Islamist brigades, including an al Qaeda affiliate, had declared an emergency and summoned all fighters to head to the fronts. After 2-1/2 years of conflict, which started when Assad’s forces fired on pro-democracy demonstrators and escalated into a full-blown civil war, the fighting has settled into a rough stalemate in which scores of people are killed every day. Aleppo has been divided roughly in half by the warring parties for much of the conflict but the government is determined to reassert total control to solidify a foothold […]