In 1904, the British geographer Halford Mackinder stood before the Royal Geographical Society and argued something that would shape a century of military and political strategy: whoever controlled the vast interior landmass of Eurasia — what he called the "Heartland," roughly stretching from Eastern Europe through Central Asia into Siberia — held a nearly unassailable position from which to eventually dominate the rest of the world.
Why the middle of a map mattered more than the coasts
Mackinder's argument rested on a specific claim about geography and power. Naval powers, like Britain, the dominant force of his era, projected strength along coastlines and sea lanes. But a state controlling the vast, resource-rich, railway-connected interior of Eurasia would be effectively unreachable by sea power, while able to project land power outward in every direction. His own often-quoted formulation ran, roughly: who rules the Heartland commands the World-Island — Eurasia and Africa together — and who rules the World-Island commands the world.
The counter-theory that said the edges mattered more
Decades later, the American strategist Nicholas Spykman pushed back with a rival framework. He argued the "Rimland" — the coastal, densely populated fringe of Eurasia, covering Western Europe, the Middle East, and South and East Asia — mattered more than Mackinder's sparse interior Heartland, since it held most of the population, industry, and resources. Control of the Rimland, not the empty centre, was what actually determined global power, in Spykman's account. His thinking is often credited as an intellectual precursor to America's Cold War "containment" strategy, aimed precisely at preventing Soviet expansion into those rim territories.
What we're still unsure about
Classical geopolitical theories like Mackinder's and Spykman's have been criticised for decades as a form of geographic determinism — treating a fixed map as though it dictates political outcomes regardless of technology, economics, or ideology, at a time when air power, satellites, cyber capability, and global trade networks have all since reshaped what "controlling territory" even means for a state's power. Even so, both theories still get invoked in contemporary discussions of Russian, Chinese, and Central Asian strategy, and geographers and strategists remain genuinely divided over how much explanatory weight century-old geographic theory should still carry in a world its authors couldn't have anticipated.
This sits inside Heartland, Rimland & Classical Geopolitical Theories, one of seven topics in Geopolitics, one of five domains in Geography, one of seventeen subjects the app can quiz you on.