146 CHAPTER FivE ■ The STaTe
Natu ral Sources of Power
Through the exercise of power, states have influence over o thers and can control the
direction of policies and events. Whether power is effective at influencing outcomes
depends, in part, on the power potential of each party. A state’s power potential also
depends on its natu ral sources of power, which are critical to both realist and radical
perspectives. The three most impor tant natu ral sources of power potential are geo-
graphic size and position, natu ral resources, and population.
Geographic size and position were the natu ral sources of power international rela-
tions theorists recognized first. A large geographic expanse gives a state automatic power
potential (when we think of power, we think of large states— Russia, China, the United
States, Australia, India, Canada, or Brazil, for instance). Long borders, however, may be
a weakness: they must be defended, an expensive and often problematic task.
Two diff er ent views about the importance of geography in international relations
emerged at the turn of the last century within the realist tradition. In the late 1890s,
the naval officer and historian Alfred Mahan (1840–1914) wrote of the importance
of controlling the sea. He argued that the state controlling the ocean routes controls
the world. To Mahan, sovereignty over land was not as critical as having access to,
and control over, sea routes.^6 In 1904, the British geographer Sir Halford Mackinder
(1861–1947) countered this view. To Mackinder, the state that controlled the Eur-
asian geographic “heartland” had the most power: “He who rules Eastern Eu rope
commands the Heartland of Eurasia; who rules the Heartland commands the World
Island of Eu rope, Asia, and Africa, and who rules the World Island commands the
world.”^7
Both views have empirical validity. British power in the eigh teenth and nineteenth
centuries was determined largely by its dominance on the seas, a power that allowed
Britain to colonialize distant places, including India, much of Africa, and North and
Central Amer i ca. Rus sia’s lack of easy access to the sea and its resultant inability to
wield naval power has been viewed as a per sis tent weakness in that country’s power
potential. Control of key oceanic choke points— the Straits of Malacca, Gibraltar, and
Hormuz; the Dardanelles; the Persian Gulf; and the Suez and Panama canals—is
viewed as a positive indicator of power potential.
Yet geographic position in Mackinder’s heartland of Eurasia has also proven to be
a significant source of power potential. More than any other country, Germany has
acted to secure its power through its control of the heartland of Eurasia, acting very
clearly according to Mackinder’s dictum, as interpreted by the German geographer
Karl Haushofer (1869–1946). Haushofer, who had served in both the Bavarian and
the German armies, was disappointed by Germany’s loss in World War I. Arguing
that Germany could become a power ful state if it could capture the Eurasian heart-
land, he set out to make geopolitics a legitimate area for academic inquiry. He founded