Though I am sympathetic, I found this book to be somewhat less original than Guns; the examples, dealing with small societies, are not (as the author allows) necessarily illustrative of our complex society -- which, admittedly, may be *more* fragile..., as a result of its complexity... as Niall Ferguson has been arguing. And while the emphasis on ecological fragility is certainly plausible, the history of man suggests that -- with a few exceptions (e.g., the 14th cen.) -- it is more often the social and purely *human* aspects that fail.
Anyway, I'm glad I've listened to these two books --
(on audible)