The Rimland Theory states that the control of Eurasia belongs the countries and territories located around the fringe of the continent. Developed by Nicholas Spykman in 1942, it counters a theory by Sir Halford Mackinder that states that control of Eurasia belongs to the powers in center of the continent.
Spykman, a professor of international relations at Yale University, published the theory in his book "America's Strategy in World Politics" during World War II. His theory was applied to military strategy during World War II, and he suggested that by uniting the coastal areas of Eurasia, the combined power could control the heartland and contain the control of the Soviet Union.
These countries and states known as the Rimland were a buffer between land and sea. Spykman argued that the upper hand belonged to these states with the power to control transit and cargo between land and sea. However, this application of the theory was unsuccessful as the states lining the coast maintained independence, never forming a united power. In more modern applications, the theory is used to examine economic power in the Rimland, or areas near the sea.
Criticisms for the theory include the idea that it was a self-fulfilling prophecy and the argument that Spykman did not take into account air control and nuclear missile head warfare.