The introduction is brilliant, as is the Vietnam case study. The material between ranges from adequate (a solid but pedestrial treatment of Britain's bungling before the American Revolution) to awful (a peevish, presentist scolding of the Renaissance Popes) to irrelevant (what is Troy, whose internal politics remain obscure, *doing* in this book as a case study?).
Saying that "It seemed like a good idea at the time," then going on to explore *why* it seemed like one, is nearly always an effective way to understand the actions of historical figures. For Tuchman, though, the answer always seems to be the same: "It seemed like a good idea because they were too stupid, venal, deluded, or blind to see that it wasn't." This doesn't help us, much, in understanding history or applying its lessons.
The notable exception to this--the one chapter where Tuchman seems willing to trace the internal logic of misgovernment--is the Vietnam chapter. If you're interested in, but not an expert on, Vietnam, that chapter may be worth the price of the book.
