Two attacks over the weekend in Afghanistan drew into even sharper relief the challenges of relations between Pakistan and the U.S. One reason: officials pointed to the first attack, in which a suicide bombing of an armored convoy killed 17 people, as a likely calling card not of the Taliban but the Haqqani terrorist network. The Haqqani network is based largely in Pakistan, and the U.S. has accused that country of supporting them. Now, American officials are in the difficult position of asking Pakistan for help in peace negotiations with the Haqqanis. David Sanger of our partner The New York Times talks more about the tangled diplomatic situation.