KABUL — U.S. troops are pulling out of Afghanistan's perilous Korengal Valley as part of a new focus on protecting population centers, NATO said Wednesday, ending a mission that saw some of the most intense fighting of the nearly nine-year American presence in the country. The isolated mountainous region of caves and canyons on the eastern border with Pakistan has been the scene of near daily exchanges of fire between NATO and insurgents, who use it as a route for infiltrating weapons and fighters into Afghanistan. While militants will likely portray the withdrawal as a defeat for foreign forces in...
