ABDUL QADIR SEDIQI and OROOJ HAKIMI TALIBAN fighters in Afghanistan have seized control of a major border crossing with Pakistan, achieving a key strategic objective during a rapid advance across the country as U.S. forces pull out. A Pakistani official said Taliban insurgents had taken down the Afghan government flag from atop the Friendship Gate at the border crossing between the Pakistani town of Chaman and the Afghan town of Wesh. The crossing, south of Afghanistan's main southern city Kandahar, is the landlocked country's second busiest entry point and main commercial artery between its sprawling southwest region and Pakistani seaports.…