This week on dialogue we examine a critical turning point in the history of the Cold War with President Nixon’s visit to China in 1972.  Joining us will be J. Stapleton Roy, who served as U.S. Ambassador to China, Singapore and Indonesia. Currently, he's director of the Kissinger Institute on China and the United States. Also, Douglas Spelman, Deputy Director of the Kissinger Institute joins us. Finally, Yafeng Xia, an Associate Professor of History at Long Island University in New York and a guest professor at the Center for Cold War International History Studies with East China Normal University in Shanghai. He's also a fellow with the Wilson Center's History and Public Policy Program.