Was the "pingpong diplomacy" that took place between the United States and China an accident of history or a planned event? Listen in to a debate on that subject, as featured on the weekly CNN program "Postscript" -- which accompanies the COLD WAR series.

CNN World Affairs Correspondent Ralph Begleiter, Russian historian Vladislav Zubok, American scholar Thomas Blanton and former U.S. Defense Secretary Donald Rumsfeld consider whether Beijing and Washington were looking for opportunities to repair relations -- or maneuvering for better positions in their Cold War rivalry.

Rumsfeld, now in private business, served as secretary of defense under President Gerald Ford and was elected to four terms as U.S. representative from Illinois. He was also an adviser to President Nixon and U.S. ambassador to NATO from 1973 to 1974.

Zubok is one of the leading historians of the Soviet side of the Cold War and the author of "Inside the Kremlin's Cold War." He has studied extensively in Soviet and American archives and has taught classes on the Cold War at Amherst College, Ohio University in Athens and Stamford University. In 1993, Zubok was employed by the Kennan Institute for Advanced Russian Studies in Washington, and since then has worked at the Norwegian Nobel Institute in Oslo and is now a fellow at the National Security Archive in Washington.

Blanton is executive director for the National Security Archive. The NSA is a non-governmental research institute providing information from U.S. government and official archives for scholars, journalists, members of Congress, lobbyists and others. Their research teases out documents still classified to give a complete picture of what really happened.