Mackinder's "Heartland Theory," proposed in 1902, views the Afro-Eurasian landmass as the global strategic core, arguing that this "Heartland," due to its geographical enclosure and concentrated resources, possesses the potential to dominate the world. The theory reveals the logic of power rivalry between land and sea: improved efficiency in land transportation, such as railway networks, empowers land-based nations to integrate vast resources, while the advantages of sea power nations, reliant on maritime trade, face challenges. Although the United States does not occupy the "World Island" heartland, its path to hegemony precisely illustrates the multi-dimensionality of geopolitics. Natural barriers of the Atlantic and Pacific Oceans shielded it from the turmoil of the Eurasian continent. In the 19th century, through westward expansion, the US seized 2.3 million square kilometers of land from Mexico, completing its territorial expansion. In both World Wars, leveraging the "offshore balancing" strategy, it sold supplies to both belligerents, weakening European powers while accumulating wealth. After World War II, the Marshall Plan rebuilt Western Europe, and the Bretton Woods system controlled global finance, combining sea power advantages with land power influence to form a global hegemony underpinned by the dollar, the US military, and technology.

The essence of the competition between sea power and land power lies in the difference in energy release forms. The sea power hegemony that began with the Age of Exploration in the 15th century was built on a "low-cost maritime transport + colonial resource plunder" model. The container revolution further reduced maritime transport costs to 1/10th of land transport. However, the "Belt and Road Initiative" (BRI), through land routes like the China-Europe Railway Express, compensates for the cost gap with timeliness (Xi'an to Duisburg direct in 11 days). In the 2022 Russia-Ukraine conflict, Russia leveraged energy as a counter-sanction to break through the SWIFT blockade, and China opened up the Central Asian corridor via the China-Kyrgyzstan-Uzbekistan railway. These examples demonstrate that land-based nations are reconstructing geoeconomics through "resource integration + infrastructure connectivity." The value of modern seaports presents a duality: the limited height of the Soviet-Korean railway bridge on the Tumen River has deprived Northeast China of direct access to the Sea of Japan, directly constraining regional economic development. Conversely, Lin Yi's competition for the Rizhao seaport aims to reduce logistics costs by more than 20% through the Xiuzhen River waterway, highlighting the leverage effect of seaports on the inland economy. However, the Swiss case demonstrates that landlocked countries can also overcome geographical constraints. The tunnel network in the Alps makes Switzerland a European railway hub. Its high value-added system, built upon precision manufacturing (watch error rate below 0.001 seconds) and finance (managing 35% of global cross-border assets), transforms the disadvantage of "borrowing ports for sea access" into a "technological barrier" advantage.

The success of landlocked countries like Switzerland and Austria reveals the code to deciphering geographical disadvantages: First, the pioneering advantage of the Industrial Revolution laid the foundation. Switzerland had achieved universal compulsory education by 1880, nurturing 28 Nobel laureates, with a research and development to industrial application conversion rate of 67%. Second, a policy of permanent neutrality avoids the attrition of war. During World War II, Switzerland absorbed 80% of Europe's gold reserves, establishing a "safe haven" reputation. Third, land transport innovation reshapes locational value. The Danube River navigation and the Central Europe high-speed rail network have made Vienna a transit hub for Eastern European trade. In 2024, semiconductor exports accounted for 12% of Austria's GDP. These countries, through a spiral of "educational investment—technological monopoly—financial deepening," transform geographical enclosure into a stability dividend, proving that in the knowledge economy era, intellectual capital is more decisive than geographical capital.

The contemporary geopolitical landscape is undergoing a resonance of "re-land powerization" and "de-sea powerization." China and Russia are advancing the development of the Arctic shipping routes, shortening Eurasian sea routes by 30%. The United States attempts to strengthen island chain blockades through the Indo-Pacific Strategy but faces the counterforce of the RCEP regional free trade agreement. The key to future hegemonic succession may depend on who can first achieve a dynamic balance of land and sea power – possessing core technologies (like Switzerland's microchip manufacturing) while constructing multi-dimensional channels (like the China-Europe Railway Express's digital customs clearance), ultimately surpassing singular geostrategic models in energy conversion efficiency. This fusion may be the ultimate answer to Mackinder's theory in the 21st century.