I have read the prologue, Part 1: Modern Montana, and the skipped Chapter 2, 3, 4, 5 in Part 2: Past Societies, then I read the chapters in Part 2 having to deal with Greenland (Chapters 5, 6, 7, 8) and chapter 9 which goes over a few success stories. I plan on returning to read the first part of Part 2.
Overall, I think Mr. Diamond does a good job of setting up a framework to analyze how and why certain societies have collapsed. It is somewhat simplistic and I think that most of the time the five point framework does not emphasize the heavy influence of environmental destruction in the societies or maybe it's because he seems overly concerned with balancing the different forces in societal collapse so that he doesn't come up with a majic bullet approach. However, this is a minor criticism.
I found what I consider to be a MAJOR issue with certain statements in Chapter 9 regarding success stories. Here is the quote from page 306:
"In thus devoting one chapter to these three success stories of the New Guinea highlands, Tikopia, and Tokugawa Japan, after seven chapters mostly on societies brought down by deforestation and other environmental problems plus a few other success stories (Orkney, Shetland, Faeroes, Iceland), I'm not implying that success stories constitute rare exceptions. Within the last few centuries Germany, Denmark, Switzerland, France, and other western European countries stabilized and then expanded their forested area by top-down measures, as did Japan. Similarly, about 600 years earlier, the largest and most tightly organized Native American society, the Inca Empire of the Central Andes with tens of millions of subjects under an absolute ruler, carried out massive reafforestation and terracing to halt soil erosion, increase crop yields, and secure its wood supplies."
Well, the western European countries that he mentions that have increased their forested area, where does he think that they get their wood from? Does Mr. Diamond think that they are self-sufficient in wood products? Hell no, they all import most of the wood products that they use. To judge a societies ability to sustainably use it's environment you have to expand to everywhere it obtains resources from. As he pointed out in the section on Montana, that Montana receives most of it's income from out of state and is not and would not be sustainable, similarly, the western European states receive most of their wood products from elsewhere including the Nordic states and the tropics.
Also, most Western European nations idea of a forest is really a mono-crop tree farm similar to what the forest service does in the US. They clear cut a stand of trees, then they plant new trees made up of a single species which they then 'harvest' again in thirty years. A thirty year stand of mono-crop trees is not a forest, that is a tree-farm. A forest can take a thousand years to mature.