Guns, Germs, and Steel — The Geographic Argument

Yali’s Question

Jared Diamond opens Guns, Germs, and Steel (1997) with a question posed to him by a New Guinean politician named Yali in 1972: “Why is it that you white people developed so much cargo and brought it to New Guinea, but we black people had little cargo of our own?”

The question is the right question, precisely framed. The global inequality that Yali observed — the enormous material and technological disparity between Western industrial nations and the rest of the world in the twentieth century — is a fact demanding explanation. The explanation matters because it shapes how we understand the world we’ve inherited and how we think about the moral dimensions of that inheritance.

The bad answer, which Diamond sets out to refute, is racial or cultural superiority. Europeans did not conquer and colonize most of the world because they were smarter, more industrious, or culturally superior. The archaeological and anthropological record provides no evidence for such claims, and the short timescale involved (the divergence in developmental trajectories is roughly 500 years of contact, against a shared human prehistory of hundreds of thousands of years) is inconsistent with any explanation invoking fixed biological differences.

Diamond’s answer is proximate and ultimate causes. Proximate causes of conquest: guns (military technology), germs (epidemic diseases that killed majority-world populations before significant military confrontation), and steel (and the broader package of food production, metallurgy, writing, and political organization). Ultimate causes: geography.

The Geographic Argument

The key geographical variables that Diamond identifies:

Continental orientation. Eurasia is oriented east-west; the Americas and Africa are oriented north-south. This matters because latitude determines climate, and species can be domesticated and spread along similar latitudes much more easily than across different latitudes (which involve different day lengths, temperatures, and seasonal patterns). Wheat domesticated in the Fertile Crescent could spread east-west across Eurasia to similar climatic zones. Corn domesticated in Mesoamerica could not spread north-south as efficiently because the temperate zone crops couldn’t cross the tropics, and vice versa. The east-west axis gave Eurasia a larger effective landmass for the diffusion of crops, animals, technology, and ideas.

Available domesticable species. Eurasia had a dramatically higher number of domesticable large mammal species than other continents. Of the world’s 14 domesticated large mammal species (cattle, horses, sheep, goats, pigs, dogs, camels, llamas, alpacas, donkeys, reindeer, water buffalo, banteng, gayal), 13 are Eurasian or North African in origin; one (the llama/alpaca) is South American. The Americas had no domesticable equivalents to horses, cattle, and pigs. Africa’s large mammals are wild in the precise sense that prevents domestication — they’re fast, dangerous, and don’t breed in captivity at scale.

Domesticable animals provided food (meat, milk), labor (plowing, transport), fiber (wool), and — most consequentially — disease. Human infectious diseases are overwhelmingly zoonotic: they originated in domesticated animals and jumped to humans. Smallpox, measles, influenza, and bubonic plague all have animal origins. Eurasia’s long history of dense human-animal cohabitation produced populations with partial immunity to these diseases. When Europeans arrived in the Americas and Australia, they brought the diseases. Indigenous populations, with no prior exposure and no partial immunity, died in enormous numbers — sometimes losing 90% of their population before significant military contact. Conquest was often simply the occupation of lands depopulated by disease.

Food production’s head start. The Fertile Crescent had the earliest and most productive suite of domesticable plants and animals, and food production there began circa 10,000-8,500 BCE. China’s food production followed around 7,500 BCE. The Americas and sub-Saharan Africa, with fewer domesticable species and less favorable geography, began food production later. An earlier start to food production meant an earlier surplus, earlier specialization, earlier development of metallurgy and writing, earlier state formation, and longer time to develop military technology.

The Steel Chapter — Technology and Its Trajectory

Guns and steel represent the military technology that made conquest possible, but Diamond’s deeper argument is about the systems that produced them. Writing enabled administrative control of complex societies, the accumulation of knowledge across generations, and the coordination of specialized labor. Political centralization allowed the organization of military campaigns and the mobilization of resources. Metallurgy enabled weapons and tools. Food production surpluses supported non-farming specialists who could develop all of the above.

These technologies spread across Eurasia through trade and cultural contact, amplified by the east-west axis. They accumulated. A society that had food production and writing was better positioned to develop metallurgy; metallurgy enabled more productive agriculture and better weapons; the surplus from better agriculture supported more specialists; specialists developed more technology. The feedback loop between food production, technology, writing, and political organization is self-reinforcing.

Societies that entered this feedback loop early — because geography gave them early access to domesticable species and allowed diffusion across similar latitudes — accumulated advantages over centuries and millennia. The disparities that Yali observed in the twentieth century were not produced in the colonial period; they were produced over ten thousand years of divergent developmental trajectories rooted in geographic starting conditions.

The Criticisms

Guns, Germs, and Steel has been criticized from multiple directions.

Geographic determinism understates human agency. Critics note that geographic factors constrain but don’t determine outcomes — many societies in similarly favorable environments developed at different rates, and some with apparent geographic disadvantages developed rapidly. The book’s geographic determinism leaves insufficient room for the choices, institutions, and contingencies that shaped specific historical trajectories.

The comparative method is selective. Diamond’s geographical analysis works better for explaining broad continental disparities than for explaining variation within continents. Why did northwestern Europe, not the Mediterranean or China (which had food production and metallurgy first), ultimately develop industrial capitalism? The geographic variables don’t clearly answer this question.

It underweights institutions. Daron Acemoglu and James Robinson’s Why Nations Fail (2012) is partly a response to Diamond: they argue that inclusive versus extractive political and economic institutions, not geography, explain differential development. Countries with identical geographies (North and South Korea; East and West Germany during partition) have dramatically different development outcomes based on institutional differences. Geography matters, but it shapes institutions rather than determining outcomes directly.

The disease chapter requires caveats. The claim that disease alone explains the collapse of indigenous American populations is probably overstated — conquest, enslavement, and deliberate violence were also substantial factors, and the role of epidemic disease varied considerably across different contact situations.

Despite these criticisms, Guns, Germs, and Steel performs an important service: it replaces a set of false and morally damaging explanations (racial and cultural superiority) with a materialist, empirically grounded account that takes the question seriously. The specific causal weights may be debatable; the refutation of the racist alternative is not.

What the Book Is Really Arguing

The deepest claim is about moral responsibility. If the global inequality Yali observed was produced by geographic starting conditions — by the accident of which continent had which domesticable species — then it is not evidence of Eurasian superiority. It is not justification for ongoing inequality. It is not destiny.

This is what makes the geographic argument politically important beyond its historical accuracy. The alternative explanations — racial hierarchy, cultural superiority — justify continued inequality as the natural order of things. The geographic argument reveals the inequality as contingent, historically produced, and therefore neither inevitable nor just.

The practical question of what follows from this — what obligations wealthy nations have toward poorer ones, what institutional reforms could alter the trajectory — is not answered by Diamond’s historical analysis. But the historical analysis is a prerequisite for asking the question honestly.