World leaders are meeting at the annual UN General Assembly against a grim backdrop of global conflict and deepening geopolitical divisions. But sometimes diplomacy can yield important results. This time last year, Siamak Namazi was released from Iran's notorious Evin Prison in a hostage-prisoner swap with the United States. He was the longest held American in Iran, a horrifying eight-year ordeal. Six months before his release, Namazi bravely called into this program from inside Evin, to make an emotional plea to President Biden. A year later, he is ready to talk for the first time, in an interview with Christiane in New York.?

Also on today's show: Irish Prime Minister Simon Harris; historian Timothy Snyder on his new book "On Freedom"?