Jared Diamond's thesis in Guns, Germs, and Steel argues that European dominance arose from geographical luck, not racial or cultural superiority. He attributes European power to the early development of agriculture, which allowed large, dense populations, technological innovation, and military strength. This advantage stemmed from Europe's geography, which supported domesticable plants and animals and facilitated the spread of innovations. Thus, Diamond contends Europeans were simply fortunate in their environmental circumstances.

Jared Diamond's theory of geographic luck as outlined in Guns, Germs, and Steel states that some regions leaped forward in progress because of access to easily domesticated grains and animals as well as lack of geographic barriers. The lack of barriers allowed innovations to spread more rapidly.

Guns, Germs, and Steel explains why the Europeans were able to conquer the world. Diamond uses externalist geographical determinism to explain that Europe had an accidental advantage of geography over other regions of the world. Externalist geography was not a cause of European success but an effect. Unlike internalist geography, externalism does not attempt to determine why certain areas have developed as they have. Instead, it focuses on how certain geographic factors influenced a region's development. In his book Guns, Germs and Steel , Jared Diamond uses internalist and externalist geography in order to explain why the Europeans were successful in their conquests. He argues that numerous circumstances combined with favorable geography made Europe exceptional from other continents during early development and expansion.

In Chapter 5 of "Guns, Germs, and Steel: The Fates of Human Societies", Jared Diamond notes that the New Guinean island of Bougainville is of the same size as the Hawaiian island of Kaua'i. However, Kaua'i supports a population of 60 000 to 80 000 people while Bougainville has only 15 000. He asks why this is so and concludes that it is because Kaua'i was settled fifty to sixty thousand years ago and had interacted with Eurasia by 3000 BC whereas Bougainville was not settled until about 3500 BC and its interaction with Eurasia did not begin for another 5000 years.

According to Guns, Germs, and Steel, Aboriginal Australians did not develop metal tools, writing, and complex societies primarily due to their inability to develop agriculture. Australia's geography and harsh climate hindered agricultural development, resulting in small, dispersed populations focused on survival. Without agriculture, they lacked the sedentary lifestyle needed for technological and societal advancements.

The geographic determinism camp argues that a nation's location on earth, its access to oceans, raw materials, certain climates, and physical barriers, impacts how it is able to develop. The Western world has more "cargo" than other parts of the world because of its location.

Jared Diamond argues that the "winners" in history were those who lived in areas with many domesticable plants and animals, allowing them to develop agriculture early. This geographic luck enabled these societies to create advanced civilizations sooner than others. The "losers" were those lacking such resources, delaying their agricultural and civilizational progress. Thus, the development and spread of agriculture were crucial factors separating historical "winners" from "losers."

In Guns, Germs, and Steel, Jared Diamond explains that the "east-west axis" refers to continents like Eurasia, which stretch more horizontally, while the "north-south axis" refers to continents like the Americas, which stretch vertically. This geographical orientation significantly impacted the diffusion of agriculture, trade, and ideas. An east-west axis allows for easier spread due to similar climates across latitudes, whereas a north-south axis presents climatic and geographical barriers, hindering the spread of crops and civilizations.

The peoples of Eurasia benefitted greatly from being along an east-west continental axis. Food production in particular benefitted from this, as it could spread much more rapidly and effectively along the same latitude than it could across different latitudes. This allowed for a faster rate of advancement in food production and, subsequently, the development and expansion of societies.

Jared Diamond identifies geography as the ultimate factor separating the world's "haves" from "have-nots." He emphasizes the availability of domesticable plant and animal species and the ease of their spread across landmasses as crucial elements. These factors led to the early development of agriculture, which in turn fostered technological advancement and societal organization. Proximate causes include technology, epidemic diseases, and political organization, which further enabled some societies to dominate others.