Are you speaking of the 1990 book CASEY, by Joseph E. Persico? Great book on the whole story of Casey. his years as head of the OSS in Europe underscores much of his later life. A must read for anyone interested in WW II and the CIA.
Peter Schweizer.
The book is, “Victory: The Reagan Administration’s Secret Strategy that Hastened the Collapse of the Soviet Union.” 1994.
Read reviews before you buy.