Towns and cities across Pakistan plunged into darkness early Sunday when what officials said was an attack by militants on a transmission line short-circuited the national electricity grid, presenting a new indictment of the government’s faltering efforts to solve the country’s chronic power crisis. Emergency efforts to end the blackout, widely described as Pakistan ’s worst ever, resulted in a partial restoration of power in the capital, Islamabad, and the most populous city, Karachi, by Sunday evening. Even so, 80 percent of the country remained without power, including the provincial capitals of Lahore, Peshawar and Quetta, an official said. The minister for water and power, Khawaja Muhammad Asif, blamed separatist rebels in the western province of Baluchistan who, he said, had blown up a critical transmission line. But experts said the attack only highlighted the growing vulnerability of Pakistan’s power grid, which has come under severe […]