Why some societies got guns and others didn't

Jared Diamond's starting point is a question posed to him by a politician in New Guinea: why did Europeans end up with so much cargo — manufactured goods, weapons, technology — while New Guineans had comparatively little? The conventional explanations, seldom stated openly but widely implied, reached for racial or cultural superiority. Diamond spent years building a different answer, one rooted in the shape of continents and the distribution of plants and animals.

Eurasia's east-west orientation meant that crops and livestock could spread across similar latitudes and climates without crossing radically different growing conditions. The Americas and Africa run north-south, meaning agriculture had to cross multiple climate zones to spread, which substantially slowed diffusion. That seemingly minor geographical difference translated, over millennia, into radically different rates of agricultural development and population growth.

A head start in food production compounded across centuries in ways that were hard to interrupt once established. Larger agricultural surpluses supported larger populations, and larger populations sustained more specialists — not just farmers but soldiers, scribes, engineers, and merchants who did not need to grow their own food to survive. Political complexity followed population density. The gap between Eurasian and other civilisations widened not because of any innate human difference but because of structural advantages that accumulated compound interest over thousands of years of compounding history.

The germs in Diamond's title matter as much as the guns and steel — arguably more, in the short run. Societies that had lived alongside domesticated animals for millennia acquired immunities to the diseases those animals carried. When Europeans arrived in the Americas, the pathogens they brought were far more destructive than any weapon they carried. Conservative scholarly estimates suggest that epidemic disease killed the great majority of indigenous Americans within a century of first sustained European contact, hollowing out the civilisations that remained before military conquest had fully run its course.

Diamond won the Pulitzer Prize for this book in 1998, and the ambition of the project remains striking. He is trying to answer the full sweep of human inequality in a single environmental argument, deliberately refusing any explanation that reaches for hierarchy between peoples. Whatever one makes of the specific mechanisms, that refusal to accept the easy answer is itself valuable and worth encountering.

The book rewards readers willing to sit with a large, unsettling question over a long period of time. Its sweep — from the domestication of wheat to the fall of the Aztec empire — is rarely attempted in one volume. The attempt, even where its specific mechanisms are contested, permanently changes how you see the distribution of wealth and power across the modern world. That shift of perspective — away from explaining inequality as natural or inevitable and toward explaining it as historical and contingent — is Diamond's most durable contribution to the way educated people think. The attempt, even where specific mechanisms are contested, permanently changes how you see the distribution of wealth and power in the modern world and why it looks the way it does.