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.

According to Jared Diamond, the three major elements that separate the world's "haves" from "have-nots" are geographic luck, access to domesticable plants and animals, and the diffusion of agriculture. These factors allowed certain societies to develop complex structures, technology, and political organization, leading to economic and military advantages over less fortunate societies.

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.

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.

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.

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, factors influencing the transition from hunter-gatherer to agricultural societies include the domestication of plants and animals, the development of food surplus, and the resulting population growth. These changes allowed for more permanent settlements, specialization of labor, and advancements in technology and social organization.

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 Maori's defeat of the Moriori in Guns, Germs, and Steel supports Diamond's argument that environmental factors shape societal development. The Maori, who lived in fertile New Zealand, developed advanced technology and military skills, while the Moriori, isolated on the Chatham Islands, remained hunter-gatherers. This contrast illustrates how geography and resources influence the fate of civilizations.

In Guns, Germs, and Steel, author Jared Diamond explains that crops spread easily in Europe and Asia partly due to Eurasia's east–west axis, which provided similar climate and environmental conditions, and due to a lack of geographical impediments to travel across Eurasia. In contrast, this spread did not happen in the Americas because the north–south axis created great disparity of climates and conditions between regions and geographical obstacles made interactions between civilizations exceedingly difficult.

A north-south axis hinders crop diffusion because different latitudes have varying climates, unlike east-west axes where climates are more consistent. Crops that thrive at a specific latitude can spread easily east to west, but struggle along a north-south axis due to differing climates. For instance, a crop flourishing near the equator in Colombia might not succeed in Argentina due to the climate differences between these latitudes.

Agriculture spread more easily from East to West due to consistent climates along latitudes, facilitating crop adaptation. East-West axes, like Eurasia, share similar growing conditions, allowing agricultural practices to diffuse efficiently. In contrast, North-South axes, like those in the Americas and Africa, encounter diverse climates, hindering the spread of crops and agricultural innovations. This geographical factor contributed to the development of civilizations in regions with East-West orientations.

Jared Diamond argues that early food production was crucial for the development of complex societies in Guns, Germs, and Steel. He posits that agriculture allowed for food surpluses, which supported larger populations, labor specialization, technological advancements, and hierarchical social structures, ultimately leading to the rise of complex societies.

The proximate causes of Pizarro's defeat of Atahualpa and the Incas in Guns, Germs, and Steel include European advances in military technology, such as steel weapons and horses, the devastating impact of infectious diseases like smallpox on indigenous populations, and the strategic use of political alliances and psychological tactics by the Spanish conquistadors.