The Rimland Theory, proposed by political geographer Nicholas Spykman in the 1940s, emphasizes the strategic importance of coastal regions surrounding the Eurasian landmass. Spykman argued that these areas, known as the "rimlands," are crucial for controlling global power dynamics, as they serve as a buffer between the sea and the interior land. According to the theory, whoever dominates the rimlands can influence the balance of power in the world. This concept contrasts with the earlier Heartland Theory by Halford Mackinder, which focused on the central area of Eurasia. The Rimland Theory highlights the significance of maritime access and alliances in geopolitical strategy.