Jared Diamond is an interesting man on first sight(see his "Guns, Germs, and Steel: The Fate of Human Societies," Norton, 1997). He is full of interesting facts about the different ways peoples have developed. That he gives too much emphasis to environmental factors in order to overcome what he thinks have been racial theories of development is understandable, yet imperfect. Human decisions (not based on race, of course) are just one of the many things he ignores. Here he focuses on Iraq and the fertile crescent and asks why it was the cradle of civilization (an accident of biogeography) and why it has declined (ecological suicide) so precipitiously. And, of course, he allows himself to pontificate about us, and what we should do about the fact that all political crises are really environmental crises. No surprise, and he becomes less interesting the more you think about what he says, but interesting enough for a quick read.
I wouldnt put much stock on Diamonds reflections on the ecological factors in the rise and decline of civilizations. I think the guy is losing it. He had a long article on this same theme in the June issue of Harpers that was nonsense from end to end. Even some of his history of the Mayas was shoddy, at best. He seems to have been overtaken by environmental correctness, which is a derivative of political correctness.