What Is Mackinder's Heartland Theory?

This mostly outdated theory focused on the role of Eastern Europe

Sir Halford John Mackinder was a British geographer who wrote a paper in 1904 called "The Geographical Pivot of History." Mackinder's paper suggested that the control of Eastern Europe was vital to control of the world. Mackinder postulated the following, which became known as the Heartland Theory:

Who rules East Europe commands the Heartland
Who rules the Heartland commands the World-Island
Who rules the World-Island commands the world

He envisioned the "heartland" which he also referred to as the "pivot area" as the core of Eurasia, and considered all of Europe and Asia as the World-Island. 

In the age of modern warfare, Mackinder's theory is widely considered outdated. At the time he proposed his theory, he only took into consideration world history in the context of conflict between land and sea powers. Nations with large navies were at an advantage over those who could not successfully navigate the oceans, Mackinder suggested. Of course in the modern era, the use of aircraft has greatly changed the ability to control territory and provide defensive capabilities. 

The Crimean War

Mackinder's theory was never fully proven, since no one power in history had actually controlled all three of these regions at the same time. But the Crimean War came close. During this conflict, waged from 1853 to 1856, Russia fought for control of the Crimean Peninsula, part of Ukraine.

But it lost to an allegiance of the French and British, who had more effective naval forces. Russia lost the war even though the Crimean Peninsula was (and is) geographically closer to Moscow than to London or Paris.

Possible Influence on Nazi Germany

Some historians have theorized that Mackinder's theory may have influenced Nazi Germany's drive to conquer Europe (although there are many who think the eastward push of Germany that led to World War II just happened to coincide with the Heartland theory).

But the concept of geopolitics (or geopolitik as Germans called it) was proposed by Swedish political scientist Rudolf Kjellen in 1905. Its focus was political geography, and combined Mackinder's Heartland theory with Friedrich Ratzel's theory on the organic nature of the state. Geopolitical theory was used to justify a country's attempts to expand based on its own needs. 

In the 1920s, German geographer Karl Haushofer used the geopolitik theory to support Germany's invasion of its neighbors, which it viewed as "expansion." Haushofer posited that densely populated countries like Germany should be allowed and entitled to expand and acquire the territory of less-populated countries.

Of course Adolf Hitler held the much worse view that Germany had some kind of "moral right" to acquire the lands of what he termed "lesser" races. But Haushofer's geopolitik theory provided support for the expansion of Hitler's Third Reich, using pseudo-science.

Other Influences of Mackinder's Theory

Mackinder's theory also may have influenced Western powers' strategic thinking during the Cold War between the Soviet Union and United States.