Tim Marshall
World leaders are not free agents, but rather captives of their physical landscapes, forced to make strategic choices heavily shaped by mountains, rivers, and oceans.
The United States achieved superpower status largely due to a vast network of navigable rivers and protective ocean borders that enabled cheap internal trade and strong defense.
Russia's pursuit of territorial buffer zones is driven by its lack of warm-water ports and its historic vulnerability across the flat North European Plain.
China is transforming into a major naval power to secure essential global sea lanes and protect the maritime choke points vital to its resource imports.