Pakistan blocked a vital supply route for US and NATO troops in Afghanistan Thursday in an apparent retaliation for an alleged cross-border helicopter strike by the coalition that killed three Pakistani frontier troops. The blockade appeared to be a major escalation in tensions between Pakistan and the United States. A permanent stoppage of supply trucks would place massive strains on the relationship between the two countries and hurt the Afghan war effort. Even a short halt is a reminder of the leverage Pakistan has over the US at a crucial time in the nine-year-old war. By late afternoon, a line of more than 150 NATO vehicles was waiting to cross the border into Afghanistan, officials said. “We will have to see whether we are allies or enemies,” Pakistani Interior Minister Rehman Malik said of the border incident, without mentioning the blockade. NATO said it was investigating Pakistani reports that coalition aircraft had mistakenly attacked its forces. The coalition has on at least one other occasion acknowledged mistakenly killing Pakistani security forces stationed close to the border. Over the weekend, NATO helicopters fired on targets in Pakistan at least two times, killing several suspected insurgents they had pursued over the border from Afghanistan. Pakistan's government protested the attacks, which came in a month during which there have been an unprecedented number of US drone missile strikes in the northwest, inflaming already pervasive anti-US sentiment among Pakistanis. Prime Minister Yousaf Raza Gilani told visiting CIA director Leon Panetta in Islamabad that Pakistan was “profoundly concerned” about the missile strikes and helicopter incursions. “Pakistan being a frontline ally in the war against terror expects its partners to respect its territorial sovereignty,” he said, according to a statement from his office.
