On April 25, a group of militants crossed the border from Pakistan to Afghanistan and opened fire on a small US outpost. When soldiers returned fire, the Pakistani border guards joined the battle—against the Americans—in an engagement that killed two and wounded seven. The episode was emblematic of Pakistan’s double game, where they supported the US in certain respects and undermined them in others. Pakistan and its leader, General Pervez Musharraf, did have shared interests with the United States. Al Qaeda was a threat to them too, and in exchange for their support, the Bush administration promised billions in foreign aid and respectful ignorance of Pakistan’s illegal nuclear weapons program. On the other hand, the Pakistani military and its spy agency, Inter-Services Intelligence, had long supported Afghan insurgencies, including the Taliban. Starting with the support of the resistance against Soviet invaders in the 1980s, Pakistan traditionally viewed the Taliban as a useful proxy for its own interests, sharing tribal ties across the border and fighting other ethnic militias supported by Pakistan’s archenemy, India.

The US failed to take account of these complexities, in part because President Bush placed great faith in his personal relationship with Musharraf, along with the presumption that the Taliban would not return in force.