More than a century ago, British geopolitical theorist Halford Mackinder formulated a foundational axiom of global power: Whoever commands the Eurasian "Heartland" controls the Afro-Eurasian "World-Island," and whoever commands the World-Island commands the world. From the British-Russian Great Game to the US-Soviet Cold War, Anglo-American grand strategy operated on the counter-doctrine of maritime primacy, using naval supremacy along the Eurasian rimlands to project power and contain the vast continental interior.