By Jiao Jian
US President Donald Trump recently publicly demanded that the Department of Defense significantly scale back joint military exercises with Republic of Korea (ROK) and explicitly expressed that "I am not happy that the United States has, long ago, agreed to participate in Joint Military Exercises with South Korea." His remarks quickly drew widespread attention worldwide. As a core institutional arrangement of the US-ROK military alliance, joint exercises have for decades been viewed as a key symbol of Washington's defense commitment to the ROK), as well as an important variable affecting the security situation on the Korean Peninsula.
Against the backdrop of profound changes in the Asia-Pacific landscape and a volatile situation on the Korean Peninsula, why is Trump dissatisfied with this long-standing joint exercise mechanism?
"Ulchi Freedom Shield" (UFS) is a joint military exercise conducted by the US and the ROK. It originated from the annual US-ROK "Ulchi Focus Lens" exercise launched in 1975 and was later renamed "Ulchi Freedom Guardian." During Trump's previous term, the US at one point announced the suspension of US-ROK joint military exercises. In 2022, the two countries resumed joint military exercises and officially named them "Ulchi Freedom Shield." This year's "Ulchi Freedom Shield" was held from August 17 to 21, ending six days earlier than originally scheduled.
For years, the US and the ROK have routinely conducted multi-dimensional and multi-level joint exercises with the basic objective of responding to conventional military threats and nuclear and missile threats from the northern part of the Korean Peninsula. Their core purpose is to strengthen the two militaries' capabilities in joint operational command and coordinated operations.
The Mutual Defense Treaty between the United States and the Republic of Korea, signed in 1953, stipulates: "Separately and jointly, by self-help and mutual aid, the Parties will maintain and develop appropriate means to deter armed attack." Joint military exercises serve as a core mechanism for implementing the treaty and enhancing the two militaries' capabilities in coordinated defense.
In name, US-ROK joint military exercises are defensive military training activities under the alliance framework. In strategic terms, however, they have long gone beyond the scope of purely defensive training, serving multiple geopolitical functions and constituting an important tool for the US to maintain its hegemony in the Asia-Pacific.
Through regular joint military exercises, the US is able to continuously strengthen its military deployment and force-projection capabilities on the Korean Peninsula, integrate US Forces Korea (USFK) into its global military operational framework, and maintain a firm grip on military dominance in Northeast Asia. In addition, through frequent, large-scale joint military activities, the US can further deepen the ROK's security dependence on it and ensure that the ROK continues to serve US global strategy.
Trump's negative remarks on US-ROK joint military exercises reflect his "America First" approach to foreign policy and utilitarian view of alliances, underpinned by clear calculations of interests and strategic logic.
First, the bargaining over defense cost-sharing is the primary economic driver of Trump's dissatisfaction. Trump has consistently maintained that the US bears a disproportionate share of defense spending within its global alliance system, while many allies have long "free-ridden" on US security protection without paying a commensurate share of the costs.
Under the US-ROK alliance framework, the US maintains approximately 28,500 troops in the ROK and bears most of the costs associated with equipment deployment, force projection, and logistical support for joint exercises, while the ROK's defense cost-sharing contributions have long fallen short of US expectations. In Trump's calculations, demanding a reduction in the scale of the exercises is essentially a bargaining chip for putting pressure on the ROK to increase its share of defense costs, thereby shifting more of the US defense burden onto its ally.
Second, it continues Trump's approach of "transactional diplomacy," treating military exercises as strategic assets that can be traded. During his first term, Trump departed from the traditional maximum-pressure policy toward the Democratic People's Republic of Korea (DPRK) pursued by previous US administrations and instead adopted "transactional diplomacy" centered on high-level meetings, seeking a breakthrough on the Korean Peninsula nuclear issue through diplomatic deals.
Following the June 2018 Singapore Summit with Kim Jong Un, Trump unilaterally announced the suspension of large-scale US-ROK joint military exercises, using it as a major concession to demonstrate goodwill toward the DPRK in exchange for denuclearization commitments. His latest call to scale back the exercises continues his approach of treating strategic assets as tradable—either using them to seek diplomatic concessions from the DPRK or leveraging them to demand greater defense cost-sharing from the ROK, thereby securing both diplomatic and economic gains.
Such utilitarian tactical adjustments are continuing to erode the foundation of trust in the US-ROK alliance. After Trump called for cuts to joint military exercises, ROK President Lee Jae-myung again called on August 18 for the transfer of wartime operational control (OPCON) to the ROK, saying that he hoped to complete the process during his term in office. From the ROK's perspective, US defense commitments are increasingly taking on "commodified" and "transactional" characteristics, while the stability and predictability of its security guarantees continue to decline. Although this erosion of trust will not unravel the alliance in the short term, it will continue to weaken the alliance's cohesion over the long run and create deep-seated concerns over the future development of US-ROK relations.
The author is from the Institute of International Strategic Studies at the Party School of the CPC Central Committee[National Academy of Governance]）
Editor's Note: Originally published on china.com.cn, this article is translated from Chinese into English and edited by the China Military Online. The information and opinions in this article do not necessarily reflect the views of eng.chinamil.com.cn.