Mackinder’s Heartland Theory and the Geopolitics of the Korean Peninsula in the 21st Century

Abstract

This study examines Halford J. Mackinder’s classic Heartland theory and Nicholas J. Spykman’s Rimland concept within the context of 21st-century East Asian security policy, with a particular focus on the strategic position of the Korean Peninsula. According to Mackinder’s theory, the fundamental law of world politics is defined by the rivalry between land and sea powers, a dynamic that resurfaces today in the form of the Sino-American competition. The central research question of this paper is to what extent classical geopolitical models can explain the contemporary security dynamics of the Korean Peninsula within a transformed technological and economic environment. Utilising a methodological framework of historical-theoretical and strategic policy analysis, the study explores the limited yet continuously useful applicability of the Heartland-Rimland logic. The main novelty and value of this analysis lie in demonstrating that South Korea, breaking away from its traditional role as a passive buffer state, has become an autonomous shaper of Rimland stability through its active middle-power strategy, technological indispensability, and robust defence industrial exports. The paper highlights the unique strategic dilemmas faced by states situated on the “rim of the World-Island” in an era of escalating great power polarisation.