LONDON, Aug 2 (Reuters) - The Syrian army's brisk recapture of parts of Damascus is unlikely to be repeated in Aleppo, where open rebel supply lines, hard-to-assail narrow streets and an apparent lack of elite manpower will limit its commanders' options. The struggle in parts of Aleppo held by insurgents is likely to be more protracted than last month's battles in the capital, inflicting further bloodshed and damage on Syria's largest city and driving more of the population out, analysts say. One reason the army's superior firepower has not translated into a quick victory may be the narrow streets and alleys that give cover for Free Syrian Army (FSA) rebels in central Aleppo. That complex geography in a city vital to Syria's economy and to President Bashar al-Assad's survival makes it problematic to bring the military's full firepower to bear. "It would destroy a lot of the city and that would undermine the 'support' of the population for the regime," said Nikolaos van Dam, a Dutch historian of Syrian politics and ex-diplomat.