Pakistan has told the US it risks losing an ally if it continues to accuse the country of playing a double game in the war against al-Qaeda, escalating the crisis in relations between the two countries. Hina Rabbani Khar, the Pakistani foreign minister, was responding to comments by Admiral Mike Mullen, the US joint chiefs of staff, who said Pakistan military's spy agency, ISI, was closely tied to the Haqqani network, the most violent and effective faction allied with the Taliban in Afghanistan. It is the most serious allegation levelled by the US against Pakistan since they began an alliance...