As South Korea continues to secure massive, back-to-back defense deals, the country has emerged as a force in the global defense industry. South Korean President Yoon Suk-yeol has made expanding the defense industry a core tenet of his presidency, promoting several policies in service of his goal to make South Korea the world’s fourth-largest defense exporter by 2027. This defense industry buildup has focused primarily on arms exports of vehicles such as combat aircraft and tanks and artillery, as well as the shipbuilding industry, though also expanding to military technology and artillery components.
While the United States has a history of constraining its allies’ ability to build up independent defense production capabilities, that has done little to stop the ROK in recent years. In fact, the United States has been fairly supportive of this shift and seen room for South Korean production to supplement U.S. production shortages, especially as U.S. weapons stockpiles have quickly dwindled over the course of the conflicts in Ukraine and Gaza. So, what does this mean for the future of the U.S.-ROK military alliance?
South Korea’s Arms Industry and Ambitions
It’s not new that South Korea is producing a large share of its own military hardware, though Yoon has emphasized the push for a greater export market as a distinct feature of his administration, highlighting the defense industry as the nation’s “future growth engine.”
Yoon’s goals for South Korea’s foreign policy and defense exports are complementary: become a “Global Pivotal State” and increase the nation’s international role and engagement through this form of economic and military diplomacy. South Korea also plans to increase its defense research and development budget over the coming years, aiming to grow its share of the global arms market from two to five percent by 2027.
South Korea’s efforts to expand its defense production have led the country to become the world’s tenth largest arms exporter in 2023, up three ranks from ten years prior. Manufacturers like Hanwha Aerospace, Korean Aerospace Industries, and Hyundai Rotem have been at the forefront of expansion, bringing in lucrative deals like the $13.7 billion sale of weapon systems to Poland in 2022; a memorandum of understanding (MOU) with the UAE in 2023 on strategic defense industry cooperation; and 51 deals and MOUs worth $15.6 billion with Saudi Arabia in 2023. As part of this push, South Korea has prioritized defense cooperation to support the development of deeper and varied partnerships beyond just seller-buyer relationships, as seen in frequent visits and talks between high-level officials.
U.S.-ROK Military Relations
Once fully dependent on U.S. military support, South Korea has worked to equalize the relationship, building up its domestic defense capacity over the last several decades. While the United States remains their primary external supporter, 76 percent of South Korea’s weapons systems were produced domestically in 2020, and the Korean Defense Acquisition Program Administration (DAPA) plans to increase domestic production of components such as semiconductors for defense systems.
That is not to say South Korea is attempting to fully detach from U.S.-provided defense capabilities. Currently, the most significant ways the United States provides for ROK defense needs are via personnel/troops, training support, and a nuclear umbrella—all of which remain firm, uncontested commitments. Especially given South Korea’s aging population, U.S. troops provide a necessary personnel boost to ROK forces and assure U.S. basing access in the country, a critical U.S. interest in the larger effort to remain engaged in the Indo-Pacific and contain and deter actors like China and North Korea.
Increased South Korean defense industrial base capacity, particularly in arms and shipbuilding, has the potential to directly support the United States. For example, with US-China competition escalating and the Biden administration pushing to rival China in shipbuilding, increased cooperation with South Korea—a global leader in shipbuilding—presents a critical opportunity to reduce U.S. dependency on Chinese commercial ships and components while fulfilling core economic and security needs, particularly as U.S. shipbuilding programs face delays. This cooperation could be as minor as increasing the use of South Korean parts in U.S. shipbuilding or as extensive as coproduction. U.S. Secretary of the Navy Carlos Del Toro recently emphasized such potential, pointing to the South Korean shipbuilding industry’s quality and capacity to increase production rates. The most substantive barrier to this partnership is not in its value to both parties, nor its general viability, but in increasingly strict “Buy America” regulations that, among other provisions, prevent any increased use of South Korean components in U.S. naval vessels.
An Exercise in Fortune-Telling: What If the ROK Succeeds?
So, it’s 2027, Yoon’s proposed deadline has passed, and South Korea has successfully achieved its goal of becoming a key player in the global defense industry. What changes? At least in terms of the U.S.-ROK relationship, likely not much.
It is feasible that South Korea will gain a bit more autonomy in navigating the international sphere, given its deepened relations with other nations via arms sales not facilitated by the United States. Such relationships may even provide Seoul greater leverage in select negotiations with the United States, given the opportunity for South Korea to diversify and strengthen its supply chains and remain less dependent on certain U.S.-provided defense capabilities.
That said, the United States and South Korea remain vital allies, and South Korean and U.S. interests do generally align; even without as many direct dependencies, South Korea is unlikely to act in ways counter to U.S. wishes. To demonstrate, one of the most notable cases of U.S.-ROK disconnect in recent years has been the failure of U.S. pressure to convince South Korea to directly supply arms to Ukraine, as South Korean law prohibits sending arms to a conflict zone. Even in this case, U.S. and ROK strategic interests remain largely aligned in upholding territorial sovereignty and supporting efforts to maintain some version of international order. Given that alignment, South Korea found a workaround to its own laws by supporting U.S. partners outside of Ukraine, approving a $134 million deal with the United Kingdom for artillery supplies for NATO forces. This has come alongside similar ROK sales to partners like Poland and nonlethal military support to Ukraine.
For those who remain skeptical whether South Korea would continue to uphold U.S. strategic interests, its dependencies on the United States would not suddenly vanish if it becomes more self-reliant. In this scenario, the role of the United States in assuring South Korean security is unlikely to change, as the primary dimensions of U.S. support go well beyond providing arms. Thus, the United States would maintain critical levers to pull to ensure that U.S. and ROK interests stay aligned.
Others fear that U.S. defense contractors would face increased competition. This may be true, but such pressures would be marginal, given the United States’ 42 percent share of the global market. Further, individual contractor needs are distinct from national strategic interests that serve the American people—which must remain paramount. Such competition could even pressure U.S. contractors to lower costs and increase the quality of their products, saving U.S. taxpayer dollars without sacrificing national security. Ultimately, ROK defense production growth will primarily provide domestic benefits and have a negligible impact on the military alliance with the United States, and will likely even lead to increased cooperation between the countries. Though unlikely to be groundbreaking, improved South Korean defense capacity could aid current collaborative efforts, such as joint aims to bolster the resiliency and reliability of defense supply chains, or spur yet unseen avenues for mutually beneficial agreements. The hurdles to this future will not vanish overnight, but a United States that supports rather than constrains the ROK’s capacity-building efforts will be best positioned to reap the benefits that a strong, capable ally can provide.
As South Korea continues to secure massive, back-to-back defense deals, the country has emerged as a force in the global defense industry. South Korean President Yoon Suk-yeol has made expanding the defense industry a core tenet of his presidency, promoting several policies in service of his goal to make South Korea the world’s fourth-largest defense exporter by 2027. This defense industry buildup has focused primarily on arms exports of vehicles such as combat aircraft and tanks and artillery, as well as the shipbuilding industry, though also expanding to military technology and artillery components.
While the United States has a history of constraining its allies’ ability to build up independent defense production capabilities, that has done little to stop the ROK in recent years. In fact, the United States has been fairly supportive of this shift and seen room for South Korean production to supplement U.S. production shortages, especially as U.S. weapons stockpiles have quickly dwindled over the course of the conflicts in Ukraine and Gaza. So, what does this mean for the future of the U.S.-ROK military alliance?
South Korea’s Arms Industry and Ambitions
It’s not new that South Korea is producing a large share of its own military hardware, though Yoon has emphasized the push for a greater export market as a distinct feature of his administration, highlighting the defense industry as the nation’s “future growth engine.”
Yoon’s goals for South Korea’s foreign policy and defense exports are complementary: become a “Global Pivotal State” and increase the nation’s international role and engagement through this form of economic and military diplomacy. South Korea also plans to increase its defense research and development budget over the coming years, aiming to grow its share of the global arms market from two to five percent by 2027.
South Korea’s efforts to expand its defense production have led the country to become the world’s tenth largest arms exporter in 2023, up three ranks from ten years prior. Manufacturers like Hanwha Aerospace, Korean Aerospace Industries, and Hyundai Rotem have been at the forefront of expansion, bringing in lucrative deals like the $13.7 billion sale of weapon systems to Poland in 2022; a memorandum of understanding (MOU) with the UAE in 2023 on strategic defense industry cooperation; and 51 deals and MOUs worth $15.6 billion with Saudi Arabia in 2023. As part of this push, South Korea has prioritized defense cooperation to support the development of deeper and varied partnerships beyond just seller-buyer relationships, as seen in frequent visits and talks between high-level officials.
U.S.-ROK Military Relations
Once fully dependent on U.S. military support, South Korea has worked to equalize the relationship, building up its domestic defense capacity over the last several decades. While the United States remains their primary external supporter, 76 percent of South Korea’s weapons systems were produced domestically in 2020, and the Korean Defense Acquisition Program Administration (DAPA) plans to increase domestic production of components such as semiconductors for defense systems.
That is not to say South Korea is attempting to fully detach from U.S.-provided defense capabilities. Currently, the most significant ways the United States provides for ROK defense needs are via personnel/troops, training support, and a nuclear umbrella—all of which remain firm, uncontested commitments. Especially given South Korea’s aging population, U.S. troops provide a necessary personnel boost to ROK forces and assure U.S. basing access in the country, a critical U.S. interest in the larger effort to remain engaged in the Indo-Pacific and contain and deter actors like China and North Korea.
Increased South Korean defense industrial base capacity, particularly in arms and shipbuilding, has the potential to directly support the United States. For example, with US-China competition escalating and the Biden administration pushing to rival China in shipbuilding, increased cooperation with South Korea—a global leader in shipbuilding—presents a critical opportunity to reduce U.S. dependency on Chinese commercial ships and components while fulfilling core economic and security needs, particularly as U.S. shipbuilding programs face delays. This cooperation could be as minor as increasing the use of South Korean parts in U.S. shipbuilding or as extensive as coproduction. U.S. Secretary of the Navy Carlos Del Toro recently emphasized such potential, pointing to the South Korean shipbuilding industry’s quality and capacity to increase production rates. The most substantive barrier to this partnership is not in its value to both parties, nor its general viability, but in increasingly strict “Buy America” regulations that, among other provisions, prevent any increased use of South Korean components in U.S. naval vessels.
An Exercise in Fortune-Telling: What If the ROK Succeeds?
So, it’s 2027, Yoon’s proposed deadline has passed, and South Korea has successfully achieved its goal of becoming a key player in the global defense industry. What changes? At least in terms of the U.S.-ROK relationship, likely not much.
It is feasible that South Korea will gain a bit more autonomy in navigating the international sphere, given its deepened relations with other nations via arms sales not facilitated by the United States. Such relationships may even provide Seoul greater leverage in select negotiations with the United States, given the opportunity for South Korea to diversify and strengthen its supply chains and remain less dependent on certain U.S.-provided defense capabilities.
That said, the United States and South Korea remain vital allies, and South Korean and U.S. interests do generally align; even without as many direct dependencies, South Korea is unlikely to act in ways counter to U.S. wishes. To demonstrate, one of the most notable cases of U.S.-ROK disconnect in recent years has been the failure of U.S. pressure to convince South Korea to directly supply arms to Ukraine, as South Korean law prohibits sending arms to a conflict zone. Even in this case, U.S. and ROK strategic interests remain largely aligned in upholding territorial sovereignty and supporting efforts to maintain some version of international order. Given that alignment, South Korea found a workaround to its own laws by supporting U.S. partners outside of Ukraine, approving a $134 million deal with the United Kingdom for artillery supplies for NATO forces. This has come alongside similar ROK sales to partners like Poland and nonlethal military support to Ukraine.
For those who remain skeptical whether South Korea would continue to uphold U.S. strategic interests, its dependencies on the United States would not suddenly vanish if it becomes more self-reliant. In this scenario, the role of the United States in assuring South Korean security is unlikely to change, as the primary dimensions of U.S. support go well beyond providing arms. Thus, the United States would maintain critical levers to pull to ensure that U.S. and ROK interests stay aligned.
Others fear that U.S. defense contractors would face increased competition. This may be true, but such pressures would be marginal, given the United States’ 42 percent share of the global market. Further, individual contractor needs are distinct from national strategic interests that serve the American people—which must remain paramount. Such competition could even pressure U.S. contractors to lower costs and increase the quality of their products, saving U.S. taxpayer dollars without sacrificing national security. Ultimately, ROK defense production growth will primarily provide domestic benefits and have a negligible impact on the military alliance with the United States, and will likely even lead to increased cooperation between the countries. Though unlikely to be groundbreaking, improved South Korean defense capacity could aid current collaborative efforts, such as joint aims to bolster the resiliency and reliability of defense supply chains, or spur yet unseen avenues for mutually beneficial agreements. The hurdles to this future will not vanish overnight, but a United States that supports rather than constrains the ROK’s capacity-building efforts will be best positioned to reap the benefits that a strong, capable ally can provide.
