Halford Mackinder's Heartland Theory posits that the central region of Eurasia, known as the "Heartland," is crucial for global power. Mackinder argued that whoever controls this area, which includes parts of Eastern Europe and Central Asia, can dominate the world due to its vast resources and strategic location. The theory suggests that land-based powers, rather than sea powers, hold the key to global influence. Mackinder's ideas have influenced geopolitical strategies throughout the 20th century, highlighting the importance of geography in international relations and the competition for control over key territories.