The ROK–U.S. Alliance: Evolving from a Military Alliance to a Comprehensive Partnership in Industry, Advanced Technology,
and Defense
Beom-jin Park
Professor Graduate School of Business Kyung Hee University/Reserve Navy Captain
The ROK–U.S. alliance is undergoing its most significant qualitative transformation since the signing of the ROK–U.S. Mutual Defense Treaty in 1953. For more than seven decades, the foundation of the alliance has been a military partnership designed primarily to deter North Korean aggression against the South. U.S. Forces Korea, the ROK–U.S. combined defense posture, and U.S. extended deterrence have served as the pillars of the Republic of Korea’s security, survival, and prosperity.
However, national security today can no longer be safeguarded by military power alone. Shipyards, semiconductor fabrication facilities, artificial intelligence (AI) data centers, nuclear power, space and cyber capabilities, drones and robotics, as well as supply chains for critical minerals and batteries, have all become integral components of national security. While the outcome of war is ultimately determined on the battlefield, we have entered an era in which the ability to deter conflict, prevail in war, and sustain military operations is increasingly determined by industrial capacity, technological superiority, production capabilities, and resilient supply chains.
North Korea and the Emerging Northern Axis of Nuclear and Military Threats
These changes are directly linked to the rapidly deteriorating security environment on the Korean Peninsula. North Korea has made its nuclear forces a central pillar of its national security strategy and is diversifying its nuclear and conventional capabilities to include nuclear warheads, intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs), hypersonic weapons, reconnaissance satellites, and unmanned aerial vehicles (UAVs). At the 9th Congress of the Workers’ Party of Korea in February 2026, North Korea announced its intention to continue strengthening its nuclear capabilities over the next five years, while also setting development goals for unmanned systems and electronic warfare capabilities. In particular, by expanding its nuclear delivery systems beyond land-based platforms to sea- and submarine-based platforms, North Korea is seeking to develop a highly survivable second-strike capability capable of evading South Korean and U.S. detection, tracking, and missile defense systems.
The expansion of North Korea’s naval capabilities reflects this broader strategy. On June 23, 2026, North Korea held a commissioning ceremony for the Choe Hyun (DDG-51), a new 5,000-ton multipurpose destroyer. At the ceremony, Kim Jong-un referred to the “nuclear armament of the navy” and ordered the construction of two surface combatants annually, including Choe Hyun-class destroyers or larger vessels such as a 10,000-ton cruiser. He also declared North Korea’s intention to conduct blue-water naval operations in the future, stating, “The era when the navy existed solely as a force for coastal defense is a thing of the past.”
Furthermore, by advancing the development of nuclear-powered ballistic missile submarines (SSBNs), North Korea is seeking to make its navy a core component of its nuclear strategy. Going forward, the nuclear threat that South Korea and the United States must address will no longer be limited to fixed missile sites, multiple rocket launcher bases, and transport-erector-launchers (TELs) on land. Instead, a far more complex operational environment is emerging—one in which the allies must simultaneously detect, track, deter, and, if necessary, neutralize covertly operating undersea nuclear forces as they maneuver across the East Sea, the West Sea, and potentially into the Pacific Ocean.
Military cooperation between North Korea and Russia further complicates the security environment. The August 2026 Japanese Defense White Paper assessed that, since 2023, North Korea has supplied Russia with millions of artillery shells and more than 100 short-range ballistic missiles (SRBMs), while sending more than 14,000 troops to the Kursk front. In the process, North Korea is gaining valuable experience in modern warfare, including the operational use of drones and other emerging technologies. At the same time, the possibility that North Korea could receive Russian transfers of reconnaissance satellite, missile, electronic warfare, and submarine-related technologies cannot be ruled out.
In addition, on June 8, 2026, Chinese President Xi Jinping paid a state visit to Pyongyang, his first visit to North Korea in seven years.
The ROK–U.S. alliance is undergoing its most significant qualitative transformation since the signing of the ROK–U.S. Mutual Defense Treaty in 1953. For more than seven decades, the foundation of the alliance has been a military partnership designed primarily to deter North Korean aggression against the South. U.S. Forces Korea, the ROK–U.S. combined defense posture, and U.S. extended deterrence have served as the pillars underpinning the Republic of Korea’s security, survival, and prosperity. However, national security today can no longer be guaranteed by military power alone.
Shipyards, semiconductor fabrication facilities, AI data centers, nuclear power, space and cyber capabilities, drones and robotics, as well as supply chains for critical minerals and batteries, have all become integral components of national security. While the outcome of war is ultimately determined on the battlefield, we have entered an era in which the ability to deter conflict, prevail in war, and sustain military operations is determined increasingly by industrial capacity, technological superiority, production capabilities, and resilient supply chains.
North Korea and the Emerging Northern Axis of Nuclear and Military Threats
These changes are directly linked to the rapidly deteriorating security environment on the Korean Peninsula. North Korea has made its nuclear forces a central pillar of its national security strategy and is diversifying its military capabilities to include nuclear warheads, ICBMs, SLBMs, hypersonic weapons, reconnaissance satellites, and UAVs. At the 9th Congress of the Workers’ Party of Korea in February 2026, North Korea announced its intention to continue strengthening its nuclear capabilities over the next five years, while also setting development goals for unmanned systems and electronic warfare capabilities. In particular, by expanding its nuclear delivery systems beyond land-based platforms to sea- and submarine-based platforms, North Korea is seeking to develop a highly survivable second-strike capability that could evade South Korean and U.S. detection, tracking, and missile defense systems.
The expansion of North Korea’s naval capabilities is an extension of this broader strategy. On June 23, 2026, North Korea held a commissioning ceremony for the Choe Hyon, a new 5,000-metric-ton multipurpose destroyer. At the ceremony, Kim Jong-un referred to the “nuclear armament of the navy” and ordered the construction of two Choe Hyon-class or larger surface combatants each year, including 10,000-metric-ton-class cruisers. He also declared North Korea’s intention to conduct blue-water naval operations in the future, stating, “The era when the navy existed solely as a force for coastal defense is a thing of the past.” Furthermore, by advancing the development of SSBNs, North Korea is seeking to make its navy a core component of its nuclear strategy. Going forward, the nuclear threat that South Korea and the United States must address will no longer be limited to fixed missile sites, multiple rocket launcher bases, and TELs on land.
Instead, a far more complex operational environment is emerging—one in which the allies must simultaneously detect, track, deter, and, if necessary, neutralize submarine-based nuclear forces operating covertly as they maneuver across the East Sea, the West Sea, and potentially into the Pacific Ocean.
Military cooperation between North Korea and Russia further complicates the security environment. The August 2026 Japanese Defense White Paper assessed that, since 2023, North Korea has supplied Russia with millions of artillery shells and more than 100 SRBMs, while deploying more than 14,000 troops to the Kursk front. Through this military cooperation, North Korea is gaining valuable experience in modern warfare, including the operational use of drones and other emerging technologies. At the same time, the possibility that North Korea could receive reconnaissance satellite, missile, electronic warfare, and submarine-related technologies from Russia cannot be ruled out.
In addition, on June 8, 2026, Chinese President Xi Jinping paid a state visit to Pyongyang—his first visit to North Korea in seven years.
On May 26, 2026, the South Korean government announced the “Master Plan for the Development of Nuclear-Powered Submarines in the Republic of Korea.” The project, known as the “Jangbogo N Project,” aims to launch the lead vessel in the mid-2030s and bring it into operational service in the late 2030s. The plan calls for a displacement of approximately 8,000 metric tons and the construction of at least three nuclear-powered attack submarines (SSNs).
The master plan sets out five principles: the use of low-enriched uranium enriched to less than 20 percent; long-duration fuel cycles; domestic design and construction in South Korea; the application of civilian nuclear and shipbuilding technologies; and comprehensive life-cycle management. It also establishes three commitments: not to possess nuclear weapons of any kind; to fulfill nonproliferation obligations in close cooperation with the United States; and to establish an appropriate safeguards framework with the International Atomic Energy Agency (IAEA). On June 2–3, a follow-up meeting on security-related fact sheets was held in Seoul to discuss issues related to nuclear fuel supply, enrichment, and reprocessing.
However, significant challenges remain. The current U.S.–South Korea Nuclear Agreement was designed primarily for civilian nuclear cooperation and does not provide a legal framework for the transfer of nuclear fuel for military propulsion. A separate U.S.–South Korea Naval Nuclear Propulsion Cooperation Agreement must therefore be concluded, which would, in turn, require congressional review under the U.S. Atomic Energy Act. To date, the United States has provided nuclear propulsion technology and fuel arrangements for submarines only to the United Kingdom and Australia.
Given that the U.S. Senate Armed Services Committee has requested a review and report on ROK-U.S. cooperation regarding South Korea’s nuclear-powered submarines as part of its deliberations on the Fiscal Year 2027 National Defense Authorization Act, it would be strategically unwise to wait until Washington reaches a final determination before preparing an appropriate response. Now is the time to ensure that both nonproliferation principles and the strategic rationale for the project are fully reflected in U.S. policy. The Jangbogo N Project is not simply a procurement program involving the acquisition of several submarines; it is a national strategic initiative encompassing reactor and nuclear fuel arrangements, design and construction, combat systems, crew training, and basing, maintenance, and sustainment infrastructure. It must therefore be institutionalized in a manner that ensures continuity and stability across changes in government.
AI and Semiconductors: The Second Pillar of the Alliance
Another pillar of the alliance is AI and semiconductors. On July 24, 2026, at the San Francisco AI Summit, Korean companies and U.S. Big Tech firms announced plans for $950 billion in semiconductor supply and production cooperation, as well as the construction of a 5-gigawatt AI data center, through six agreements. Samsung Electronics will collaborate with Broadcom on the supply of advanced memory and AI semiconductor foundry services worth $200 billion over five years, while SK Group will work with NVIDIA and other partners on data center construction and long-term memory supply. Hyundai Motor Group will partner with NVIDIA and Waymo on “physical AI” initiatives, while Naver will secure $10 billion to build a global AI factory.
The two countries have a highly complementary relationship in the AI sector. The United States possesses world-class capabilities in GPUs, AI foundation models, cloud computing, and semiconductor design, while South Korea has demonstrated significant strengths in high-bandwidth memory, semiconductor manufacturing and packaging, high-volume production, and quality control. The advanced packaging plant that SK hynix broke ground on in Indiana on August 27, 2026, exemplifies this emerging partnership.
With an investment of more than $4 billion, the facility is expected to begin mass production of seventh-generation HBM in the second half of 2029. Wafers manufactured in South Korea will be packaged and tested in the United States for domestic supply, while the company will work with U.S. universities to jointly develop next-generation technologies. In the AI era, semiconductors, data centers, electricity, software, talent, and critical minerals are increasingly interconnected as components of a single strategic supply chain. If the two countries build and secure this supply chain together, it could become a critical strategic asset extending well beyond its economic value.
Defense Industry Cooperation: From Buyer to Partner
The defense industry also requires a similar transformation. Future defense cooperation must move beyond a one-way model in which South Korea primarily purchases U.S. weapons and instead evolve into a virtuous cycle of “joint research, development, production, operation, and export.” The Memorandum of Understanding on “Drone and Anti-Drone Cooperation and Market Participation,” signed by South Korean and U.S. defense authorities on May 15, 2026, symbolizes this shift. The two countries agreed to establish joint supply chains and common standards and certification systems, while also pursuing the registration of South Korean-made products on the U.S. Department of Defense’s online drone trading platform. This goes beyond simply expanding defense exports; it could provide the foundation for a “joint defense industrial ecosystem” in which the armed forces of both countries operate interoperable systems and leverage each other’s production capacity during times of crisis.
However, it would be problematic if, under the banner of joint development, South Korea were effectively relegated to a production role while the United States retained exclusive control over critical technologies, intellectual property rights, and export authorization to third countries. Negotiations on the ROK–U.S. Defense Mutual Procurement Agreement (RDP-A) have been underway since 2022. Although the two sides agreed in 2024 to accelerate efforts to conclude the agreement, negotiations remain unresolved because of objections raised in the U.S. Congress and an ongoing review by the Government Accountability Office.
Once the RDP-A is concluded, the price disadvantages associated with the U.S. “Buy American” policy would be reduced or eliminated, allowing South Korean defense products to compete on more equal terms with U.S.-produced systems. For MASGA and drone cooperation to generate tangible results, this institutional gap must first be addressed. A genuine defense-industrial partnership is not simply about jointly manufacturing weapons; it is about sharing risks, costs, technologies, markets, and returns.
Supply Chains and Reassessing the “Security with the U.S., Economy with China” Framework
Supply chains cannot be overlooked either. A single advanced weapons system incorporates countless semiconductors, sensors, software components, rare earth elements, and specialty metals; if even one critical component becomes unavailable, the entire production process can be disrupted. The benchmark for strategic competition is therefore shifting from “How cheaply and quickly can it be produced?” to “How resilient and secure is the supply chain that supports it?” The traditional division of labor reflected in the concept of “security with the U.S., economy with China” also requires a fundamental reassessment in strategic industries.
At the same time, severing all economic ties with China would not serve South Korea’s national interest. What is needed is not an ideological or emotional approach to “decoupling from China,” but a strategy of disciplined risk management. A more realistic approach is to establish “trusted supply chains” in which South Korea develops domestic capabilities in strategically indispensable technologies, while sharing risks and burdens with the United States, Japan, Australia, Canada, Europe, and other like-minded partners in areas where diversification is feasible.
The Foundation of a Military Alliance
However, expanding cooperation in industry, advanced technology, and defense cannot substitute for the military alliance, which remains the foundation of the broader partnership. Quite the contrary. As the North Korean nuclear threat intensifies and military cooperation between North Korea and Russia becomes increasingly institutionalized, industrial and technological cooperation can develop sustainably only if the combined defense posture and extended deterrence commitments remain credible and robust.
At the sixth U.S.–ROK Nuclear Consultative Group (NCG) meeting, held in Seoul on June 11, 2026, the two sides reaffirmed their commitment to extended deterrence and agreed to deepen cooperation on the operational concept of Combined Nuclear and Conventional Integration (CNI), crisis response, and the employment of strategic assets. The NCG, which initially functioned largely at a symbolic level, is increasingly developing into a substantive mechanism capable of shaping combined operational planning. Even as dialogue with North Korea remains necessary, the combined defense posture must not be weakened as a concession in negotiations. Dialogue and deterrence are not mutually exclusive; rather, they are complementary pillars that must operate simultaneously.
Six Tasks for the Future
The tasks ahead are clear. First, while maintaining extended deterrence and the combined defense posture as the central pillars of the alliance, we must integrate shipbuilding, SSNs, AI, semiconductors, nuclear energy, space, cyber capabilities, drones, and critical minerals into a comprehensive national security framework. Second, we must develop MASGA into a mutually beneficial shipbuilding partnership and pursue expanded cooperation while continuing efforts to remove legal and regulatory barriers to the construction of U.S. Navy vessels in South Korea. Third, the Jangbogo N Project must address two priorities simultaneously—concluding a separate cooperation agreement governing nuclear-powered submarine development and revising the ROK–U.S. Nuclear Agreement—while building indigenous capabilities in design, construction, operation, maintenance, and sustainment.
Fourth, cooperation in AI and semiconductors must be expanded to include resilient supply arrangements for military AI and semiconductors used in command and control, unmanned systems, and missile defense. Fifth, while concluding the RDP-A, we must protect the technology and intellectual property rights of South Korean companies and establish a framework for joint exports to third countries. Sixth, the two countries should establish a high-level ROK–U.S. “Strategic Consultative Body on Industry, Advanced Technology, and Defense” to coordinate and integrate cooperation across all of these domains.
Toward the Next 70 Years
While the alliance of the past was fundamentally a security partnership that combined U.S. military power with South Korea’s strategic geographic position, the alliance of the future must become a comprehensive strategic partnership that combines U.S. military power and cutting-edge technologies with South Korea’s industrial capabilities in shipbuilding, semiconductors, nuclear energy, and defense. The alliance of the future must not remain merely an “alliance that fights together.” It must evolve into an alliance that researches and develops together, builds and sustains together, produces and exports together, and protects each other’s industries and supply chains in times of crisis. Building a relationship in which each side provides indispensable strategic value to the other is the most realistic and sustainable path for the ROK–U.S. alliance as it evolves beyond a traditional military alliance into a comprehensive partnership encompassing industry, advanced technology, and defense.