Nostalgia reigns in this account of how the film industry responded to WW II. Hoopes (Ralph Ingersoll, 1985, etc.), Washington bureau chief of Modern Maturity, has written extensively on the ``good old days,'' and his latest effort is in the same vein of mildly revisionist memorabilia. Even before the start of the war, some members of of Hollywood's acting community--notably the British and progressive-minded Jews--were already alert to the dangers posed by the Nazis, and it is with these farsighted individuals that Hoopes begins his chronicle. Vienna-born actor Helmut Dantine, for example, spent three months in a concentration camp as a result of his anti-Nazi activism before coming to America. After Pearl Harbor, however, the entire filmmaking community pitched in eagerly with bond drives, USO tours, and enlistments. ``In many ways, World War II was Hollywood's finest hour,'' Hoopes asserts. ``Just about every male star not in the service went on at least one USO tour; among actresses, participation was close to 100 percent.'' (A notable exception was Greta Garbo.) Although the reaction of the industry to the war is a potentially fascinating story, and Hoopes has some splendid anecdotes, this book suffers from a warmed-over feeling. The first and biggest problem is Hoopes's working method: By his own admission, the entire book was gleaned from secondary sources, most of them movie-star autobiographies--not notably reliable sources of information. As a result, where two reports of events conflict, Hoopes merely repeats both versions and leaves it to readers to decide who is telling the truth; and where a star is not forthcoming about his war record, Robert Montgomery for instance, Hoopes offers silence. This is just lazy reporting. Finally, although the book is organized in a loose chronology, it has no real structure, and meanders aimlessly, if amiably, from anecdote to anecdote. A disappointing failure to explore a rich topic.