Pakistan and Afghanistan’s Taliban authorities are locked in a widening tit-for-tat confrontation that neither side seems willing to defuse, analysts said, warning the exchanges risked settling into a prolonged conflict along one of Asia’s most volatile borders.Islamabad has vowed to keep striking military targets inside Afghanistan until the Taliban takes action against the Tehreek-i-Taliban Pakistan (TTP) and other militant groups Pakistan says operate from Afghan soil.Pakistani warplanes...