convinced MacKinder that the vast expanses of Asia could be connected via rail.
His thesis also was influenced byorganic theory, as he spoke of history and physi-
cal geography as being “organically connected,” and there are clear undertones of
environmental determinismin his ideas regarding the relationship of history and
physical geography.
MacKinder conceived of world geography as being composed of “natural seats
of power,” with the pivot region being supreme and representing dominant land
power. Arranged in two bands surrounding the pivot area were regional arcs of
power, the “inner crescent,” or sometimes referred to as the “marginal” crescent,
and the “outer crescent,” or “insular” crescent. The inner crescent was controlled
for the most part by the European colonial powers and swept from Western Europe
toward the southeast, including India and the entire eastern coastline of Asia, all
the way through eastern Siberia. The inner crescent completely enveloped the
pivot region, except on the northern coast, and was controlled by a combination
of land and sea power. The outer crescent consisted of Great Britain, Australia,
Japan, southern Africa, and North and South America. The countries of this zone,
all maritime nations, were completely dependent on sea power to protect their
political interests and commerce. Interestingly, MacKinder did not view the
United States as a vital player in the dynamic between the inner crescent and the
pivot region. He believed that the construction of the Panama Canal would direct
American interests toward the Pacific Basin and away from the Eurasian landmass.
Great Britain, as part of the outer crescent, was compelled to cultivate political
alliances with countries in the inner crescent so as to establish “bridge heads”
there that would prevent the expansion of any power from controlling the pivot
region. The rise of the British Empire in the previous centuries, noted MacKinder,
was “a short rotation of marginal power round the southwestern and western edge
of the pivotal area,” which only temporarily obscured the pre-eminence of the
pivot area.
Although MacKinder did not use the term “heartland” during the initial reading
before the RGS, he would later introduce that term in a revision of the theory,
using it to replace “pivot region.” In 1919, in the aftermath of World War I, he
reformulated the theory in a book-length study,Democratic Ideals and Reality.
In this work MacKinder introduced several new regional terms into his original
thesis. The “pivot region” now became the “heartland,” with some slight modifica-
tions of the original boundaries—the heartland was somewhat larger, as it included
western China and more of Siberia. MacKinder now referred to the “World
Island,” a vast territory that was composed of most of Europe, Asia, and Africa.
In the revised theory, the World Island represented a huge repository of resources
that could be exploited by an aggressive power bent on world domination. The
key to controlling the World Island was control of the heartland’s gateway region,170 Heartland Theory