More than 90 percent of global trade moves by sea. Energy resources, raw materials, semiconductors and critical minerals all depend on secure maritime shipping lanes. Nations that command the seas command the global economy, and those that command the global economy ultimately shape the international order. Against this backdrop, the Korea-U.S. alliance is entering a new phase, evolving beyond a traditional land-based security partnership into a broader maritime alliance.

Although the United States possesses the world's most powerful navy, the competitiveness of its shipbuilding industry has declined significantly. Since the end of the Cold War, the number of U.S. shipyards and skilled workers has steadily decreased, limiting shipbuilding capacity and slowing naval expansion. Even the U.S. Navy's maintenance, repair and overhaul (MRO) capability has become insufficient to fully support the Indo-Pacific strategy. This decline is partly the result of decades of protectionist maritime policies, including the Jones Act and the Byrnes-Tollefson Amendment, which gradually eroded America's international competitiveness in shipbuilding.

While the United States focused primarily on its domestic market, Korea steadily strengthened its competitiveness through intense competition with Japan and China while continuously investing in technological innovation. As a result, Korea has become one of the few countries capable of independently designing and constructing not only world-class commercial vessels but also advanced destroyers, submarines and naval support ships.

Against this backdrop, the United States has increasingly turned to Korea as a strategic partner in revitalizing its shipbuilding industry, placing both countries at the beginning of a new era of cooperation. If successfully institutionalized, this partnership could become a new model for the global shipbuilding industry. The United States must substantially expand the construction of both naval and commercial vessels to restore its maritime power and logistics competitiveness, while Korea possesses world-leading design, engineering and manufacturing capabilities. Put simply, when the United States defines strategic demand, Korea has the capacity to meet it rapidly and efficiently. This partnership is no longer simply about building ships together; it is laying the foundation for a new maritime alliance dedicated to safeguarding a free, secure and open maritime order.

This explains Washington's growing interest in Korea's shipbuilding industry. Korean shipyards have begun undertaking MRO projects for U.S. naval vessels, while voices in Congress increasingly advocate utilizing the shipbuilding capacity of trusted allies. As China rapidly expands both its global shipbuilding market share and naval power, it has become increasingly difficult for the United States to respond through domestic capacity alone. Industrial cooperation with allies has therefore become an essential component of U.S. national security strategy.

For Korea, this presents an extraordinary opportunity. Korean shipbuilders have long dominated the global markets for liquefied natural gas carriers and ultra-large container ships. The next frontier, however, extends well beyond commercial shipping to include naval MRO, fleet modernization, new warship construction, unmanned surface and underwater systems, environmentally sustainable vessels, digital shipyards and smart shipbuilding technologies. Cooperation with the U.S. Navy could become a decisive catalyst for expanding Korea's shipbuilding industry into higher-value defense sectors.

Beyond industrial competitiveness, the Korea-U.S. shipbuilding partnership also carries profound implications for supply-chain resilience. Shipbuilding is a comprehensive industry that integrates steel, propulsion systems, electronics, artificial intelligence (AI), software, defense technologies and nuclear engineering. Revitalizing a single shipyard stimulates growth across hundreds of suppliers and small and medium-sized enterprises. Expanding bilateral shipbuilding cooperation will therefore strengthen the manufacturing ecosystems of both countries, creating not merely greater exports but a new industrial alliance.

Furthermore, Korea's development of next-generation destroyers, submarines and unmanned naval systems creates additional opportunities for technological collaboration with the United States. Joint development of standards for AI-enabled naval operations, digital shipyards and smart maintenance systems would enable both countries to play a leading role in shaping the future maritime security architecture.

Nevertheless, significant challenges remain. U.S. protectionist policies, legal restrictions on naval shipbuilding, technology security concerns and limitations on defense technology transfers continue to pose substantial barriers. Korean companies also remain concerned that changes in political leadership or government policy could undermine the certainty required for long-term investment. Bilateral shipbuilding cooperation therefore cannot depend solely on commercial contracts.

Most importantly, both governments must establish institutional guardrails that guarantee policy predictability, enabling Korean companies to invest billions of dollars in U.S. shipbuilding facilities and workforce development with confidence. Such long-term investment requires assurance that tax incentives, regulatory approvals, technology protection and contractual commitments will remain stable across political cycles. To achieve this, the two governments should establish a permanent bilateral shipbuilding cooperation mechanism while institutionalizing investment protection and principles for technology cooperation through sustained high-level dialogue. Only then can Korea invest with confidence while the United States secures the industrial capacity necessary to rebuild its maritime strength, creating a genuinely mutually beneficial alliance.

Equally important, this opportunity must not become a one-time commercial transaction. If cooperation is limited to maintaining several U.S. naval vessels or constructing a handful of ships, its strategic value will remain limited. Instead, the two countries should build a long-term framework encompassing joint research and development, workforce training, supply-chain integration, collaborative exports and the development of next-generation naval platforms. Only then can this partnership truly deserve the name "shipbuilding alliance."

The competition for maritime dominance in the 21st century has already begun. The United States needs the shipbuilding capabilities of trusted allies, while South Korea possesses world-class technology and production capacity. Never before have the strategic interests of the two nations aligned so closely. Shipbuilding cooperation between Seoul and Washington is far more than an economic partnership; it is emerging as a central pillar of a strategic alliance dedicated to preserving a free, secure and open maritime order. The Korea-U.S. shipbuilding alliance is not merely about constructing warships together — it is a long-term national strategy for shaping the future balance of maritime power.

Moon Keun-sik is adjunct professor at Graduate School of Public Policy of Hanyang University in Seoul.