"My time in the Obama administration turned out to be a deeply disillusioning experience." It was close to midnight on Jan. 20, 2009, and I was about to go to sleep when my iPhone beeped. There was a new text message. It was from Richard Holbrooke. It said, "Are you up, can you talk?" When I called, he told me that Barack Obama had asked him to serve as envoy for Afghanistan and Pakistan. He would work out of the State Department, and he wanted me to join his team. "No one knows this yet. Don't tell anyone. Well, maybe...