evidence: A key U.S. diplomat is trying to explain what went wrong in Afghanistan. Zalmay Khalilzad left the U.S. government last week. He negotiated a peace deal with the Taliban under President Trump. President Biden kept that commitment, resulting in a chaotic U.S. withdrawal. But Ambassador Khalilzad is defending his work. He talked with Steve Inskeep. [...] KHALILZAD: Well, let's separate issues from each other. First, what did the agreement say, and did they comply? The Taliban agreed to sit with the Afghan government to negotiate. They did that. On the violence issue that you referred to, since the signing of the agreement until the withdrawal, for 18 months, not a single American was killed by the Taliban, although... [...] KHALILZAD: I believe that they did make an agreement that they observed, as I give you the example of not attacking or killing a single American soldier. But it wasn't - we weren't trusting them, that we were monitoring what they were doing. We were responding when we thought it was appropriate.