Diamond has provided (elsewhere) a convenient definition for "collapse" as "drastic decrease in human population numbers and/or in political, economic, or social complexity"; a definition which, of course, includes all civilizations that ever existed. His definition also seems to include any place on Earth where new civilizations replaced old civilizations (for example, Diamond often mentions Java as a place where "societies have existed continuously for thousands of years", but the people of today's Java are Muslims, which is not what Java was "thousands of years ago").

The fundamental weakness of his approach is that he does not use a word of caution at the very beginning. Much of what he writes is based on our understanding of how the environment used to be. That is an approximation at best. There were certainly a lot more forests, but that is true for all places on Earth. Beyond such trivial statements, it is really hard to reconstruct how the environment looked like when a civilization was at its peak.

Diamond's thesis is that some societies ended up destroying the very source of their livelihood. The thought never occurs to Diamond that a society might simply change source of livelihood. If we run out of wood, we can build houses using a different material. If we run out of boats, we can simply start farming or hunting instead of fishing. The history of humankind is not a mechanical repetition of the same lifestyle day after day. Quite the contrary.

His list of pre-industrial societies that collapsed include such obscure civilizations as Cahokia (in Missouri) but does not include such world-famous civilizations as the Mongols and the Arabs, which built empires slightly bigger than Cahokia. He also spends precious little time on Athens, Rome and Persia. He carefully avoids civilizations such as China and Britain, that completely destroyed their original territory (China is the master of repeated large-scale deforestation) and still became huge powers (China "is" the only civilization that has lasted thousands of years and gets only 20 pages and only for the modern period, and Diamond does not realize the contradiction when he mentions the colossal environmental damage caused by Mao's rule in the same page with the exceptional economic boom that came after it). He also neglects India, a good example of a region where societies caused little or no environmental damage but had a tendency to disappear very quickly: perhaps precisely because, unlike the British and the Chinese, they did not massively exploit their natural resources?

Diamond offers an explanation for the Rwandan holocaust (such a vague explanation that i would not know how to summarize it), but ignores the fact that many overcrowded places in the world never experienced anything even remotely similar to what happened in Rwanda. He discusses Haiti (which he considers "the poorest country in the New World" because he never traveled to Cuba) but fails to compare it with comparable countries such as the Philippines or Indonesia that had similar histories. What conclusions to draw from these examples is not clear.

In general, he offers one remote, obscure, and often unverifiable example that supports his theory but blatantly ignores obvious counterexamples that could prove just the opposite.

Diamond seems to think that Japanese society qualifies as a "thousand-year old" civilization, and praises the fact that Japan has been capable of re-foresting what it deforested. Even assuming that the Japanese civilization was not destroyed by the USA in 1945, Diamond neglects the fact that the Japanese people, far from being proud of their environmental wisdom, commit suicide at a rate higher than most other people on the planet.

The truth is that the well-known civilizations don't quite fit his rules, and thus he prefers to dwell on little-known civilizations such as the Anasazi of North America and the Vikings of Greenland (one hundred pages for a community of 5000 people!), that have one thing in common: they wrote very little, so we know very little, so we can claim pretty much anything we like about the causes of their "collapse". He himself writes that "half of [the societies examined in the book] lack writing" but he doesn't explain why he would focus on societies that left no documents behind. He thinks that "the clearest examples" of collapses of isolated societies involve remote Polynesian islands. One wonders how this collapse could be so "clear" if those societies did not leave us any document: we don't even know how they functioned. We might have "theories" on what happened there, but "clearest" sounds a bit exaggerated. (And, by the way, far from collapsing, the Norse did pretty well: Norway is now one of the wealthiest countries in the world. It all depends on when you decide that a "civilization" has ended: sometimes it simply morphed into something else because people got tired of warfare and found a better way to spend their time; and the Vikings who managed to live 450 years in Greenland can hardly be considered a "failure": for those days i consider it quite a feat). When talking about the Anasazi, he tries to increase their importance by stating that they had the "tallest buildings erected in North America" until the invention of the skyscraper. I have visited both the most famous Anasazi sites and the eight-meters tall Square Tower is the highest structure i saw. When he offers examples of success, he picks the New Guinea highland (hardly a very developed place, in my humble opinion) and the Tikopia Islands (don't ask me where they are located) despite living in an age in which there are many world powers that have been around for millennia (China, India, Britain, Russia, France, etc).

The book opens in grand style with a 50-page chapter on... Montana! To the rest of the world (that has probably never heard of such a place or cannot find it on the map) this is a bit laughable. Why not start with ancient Egypt or ancient Greece instead?

In the introduction Diamond clarifies that he chose these specific societies because they can teach us something about modern societies, but this requires a superhuman flight of imagination. Modern societies (even the poorest ones) are infinitely more complex and interdependent than the ancient "civilization" of the Easter Islands. Today we have very rich states like Qatar that occupy deserts; we have rich states that specialize in investing money in other states (Singapore); and we have states whose economy has improved dramatically not because of different attitudes towards the environment or military conquests but because of ideological shifts following the Cold War.

The only major civilization that Diamond examines is the Maya, but in one of the shortest chapters (21 pages versus the 50 pages devoted to Montana). His conclusions are... pretty much all possible conclusions, with a disclaimer that archeologists disagree on just about anything about the Maya.

When he deals with Rwanda, his explanation for the genocide is purely Malthusian, despite the fact that he himself has started by recounting how massacres of Hutus by Tutsis and viceversa have been going on for centuries (when there was no population pressure). He bases his argument on little more than the opinions of two economists from Belgium ignoring a huge bibliography on the subject written by all sorts of experts.

It is difficult to take on specific sentences because Diamond tends to be as vague as possible. For example: "collapses for ecological or other reasons often masquerade as military defeats". Most people will read this sentence as "collapses for ecological reasons often masquerade as military defeats"; but, as you are ready to ask him to explain the most famous battles in history from an ecological viewpoints, you notice the "or other reasons". The sentence is cunningly misleading. What it really states is "collapses due to anything often masquerade as military defeats". We all agree on that one: in most cases there is a bigger reason behind a military defeat. A lot of the book misleads with sentences that are designed to imply something while literally they don't. After a thorough retelling of the histories of Haiti and Dominican Republic, he asks why one is extremely poor and the other one is doing relatively well and concludes: "Part of the answer involves environmental differences". His own account of the two countries has shown such a huge difference in the way they were created and they were governed that it is not difficult to guess the reasons for the wealth gap between them, but that sentence seems to imply that ultimately it's all about the environment, except if you read it carefully it says "part of the answer", which, of course, is true for anything that takes place anywhere in the universe. (Incidentally, many will probably read the entire chapter and not realize the most obvious difference between those two countries, that one is black and one is white, but it must be politically incorrent in the USA to imply that a country created by former African slaves is likely to perform less well than a country created by educated European aristocracy; Guyana, with a gorgeously lush environment, is probably the poorest country in South America and, lo and behold, its origins too go back to slavery and indenture - Haiti and Guyana are as poor and messy as their sister countries in Africa).

Here and there one can find interesting insights amid the mass of trivial notions (that you can get from any news media) and of vague prescriptions. For example, in the apocalyptic chapter on Australia (that will surely be uninhabited or at least starving within a generation if Diamond's theory is correct) he mentions "The simple way for Australia... to reduce greenhouse gas emissions would be to eliminate cattle". That's, literally, food for thought.

Personally, I think that the secret in survival of a civilization rests in the ability of its people to exploit the environment to continuously reinvent the economy. Some civilizations did it better than others, that's all. And Darwinian selection took care of the ones that did it less well. Deforestation per se did not cause anybody's collapse: in some cases (from ancient Mesopotamia to western Europe) it caused a political, economic, cultural and technological boom. In other cases (including the ones that Diamond focuses on), it may (may) have contributed to their decline.

Diamond would have a hard time explaining why Napoleon lost and why Alexander won. Others have explained both facts, quite convincingly, without any need to discuss environmental issues.

Towards the end, as he lists the damages caused by the modern globalized world to the planet, he takes aim at the belief that technology will find solutions to everything. That would have been a much more interesting and original book: why not?

A more interesting title for Diamond's book would have been: "How Societies Choose to Read Books like This One". There is a passion for hearing that we are laying the foundations for our own apocalypse, a passion that (in the Christian world) has been around for two thousand years.
Other than that, there is little substance in what Diamond writes. His premises are way too weak to justify any strong conclusion.
Now i am dying to find out how the Vikings from Norway managed to survive 450 years on Greenland in an age with no airplanes, cargo ships, etc.
I recommend instead "Forest and Civilisations", edited by Yoshinori Yasuda, written by leading scholars of environmental archeology.