Mr. Feis, who has written several notable books on recent diplomatic history, here continues the narrative of his earlier "Churchill-Roosevelt-Stalin." The author had access to the State Department recòrds on the Potsdam Conference, as well as to records in the possession of W. Averell Harriman and James Byrnes. The story is of a fateful and melancholy period of months: "History hints that what is done during the first few months after a great war ends is likely to determine the fate of the next generation, perhaps of many generations."