FILE - Then First lady Pat Nixon watches behind him, then U.S. President Richard Nixon shakes hands with a Chinese girl in Beijing on Feb. 24, 1972 during his tour of historic sites of the Chinese capital. At the height of the Cold War, U.S. President Richard Nixon flew into communist China's center of power for a visit that over time would transform U.S.-China relations and China's position in the world in ways that were unimaginable at the time. (AP Photo, File)