FILE - In this Feb. 21, 1972, file photo, Chinese communist party leader Mao Tse-Tung, left, and U.S. President Richard Nixon shake hands as they meet in Beijing. Nixon's visit marked the first time an American president visited China. From World War Two‚Äôs Yalta gathering through U.S.-Soviet summits in the Cold War, Nixon‚Äôs trip to Chairman Mao‚Äôs China and various attempts to forge peace among Israeli, Egyptian and Palestinian leaders, the art of the summit has long been a rare and rarified moment where the world stops agape. (AP Photo/File)