S.M. Plokhy, history professor at Harvard University, recounts the Yalta conference that brought Winston Churchill, Franklin Delano Roosevelt, and Joseph Stalin together for eight days in February,1945 to discuss the organization of post-World War II Europe.  Mr. Plokhy refutes the contention made by many of Roosevelt's critics that the president ceded too much to Stalin and that his actions laid the groundwork for the Cold War.  S.M. Plokhy presents his book at the Weatherhead Center for International Affairs at Harvard University in Cambridge, Massachusetts.