In all the years since the 1953 armistice that saw a cessation of fighting in the Korean war, US troops have been based in South Korea with the aim of deterring North Korea and defending the South. But concerns are mounting in Seoul that the Trump administration may be looking to expand the role of the US Forces Korea (USFK) beyond this original mission. Bilateral tensions escalated further last week following a Wall Street Journal report that the Pentagon is weighing the relocation of approximately 4,500 of the 28,500 American troops currently stationed in South Korea to bases in Guam and other locations across the Indo-Pacific.
In March, Under Secretary of Defence for Policy Elbridge Colby advocated prioritising US military assets to counter China. That same month, a document, known as the Interim National Defence Strategic Guidance, reportedly distributed by Defence Secretary Pete Hegseth, particularly rattled Seoul, as it states that the potential invasion of Taiwan should be given precedence over other dangers in the region.
According to the document, the United States is prepared to “assume risk in other theatres” due to personnel and resource constraints and will pressure allies “to take on the bulk of the deterrence role” against other threats, including North Korea. The document reportedly singles out NATO, stating the bloc must take on “far greater” burden sharing because the United States will be reluctant to provide forces with its priorities focused elsewhere. Since taking office, Donald Trump has also made it clear that Washington expects Seoul to take more responsibility to counter the threat from Pyongyang.
Alarm bells in Seoul rang even louder when USFK Commander Xavier Brunson stated earlier this month that troops stationed on the Korean Peninsula serve purposes beyond deterring North Korea. Brunson referred to South Korea as “the closest allied presence to Beijing”, defining the country as “an island or a fixed aircraft carrier floating in the water between Japan and mainland China”.
During a Senate hearing last month, however, US Indo-Pacific Command Commander Admiral Samuel Paparo warned that reducing US troop presence in South Korea would increase the likelihood of a North Korean invasion. In response to recent reports about possible troop withdrawals from Korea, Seoul’s Foreign and Defence Ministries both stated that no such discussions on the matter had taken place with the United States.
With North Korea more emboldened than ever due to its profitable economic and military ties with Russia, Seoul cannot afford to create any potential opening for Pyongyang.
With South Korea’s government paralysed ever since the impeachment of President Yoon Suk-yeol and a power vacuum likely to remain at least until the 3 June presidential elections, the lack of leadership and decisive action from Seoul could have lasting, even unwanted, effects on the country’s security situation.
While Seoul remains unable to respond to the rapidly changing situation, Tokyo has been quick to present its own proposals to US officials. When Hegseth visited Tokyo on 30 March, Japan proposed a “one-theatre” approach to handling security challenges in the region. According to this concept, the East China Sea, the South China Sea, the Korean Peninsula and the surrounding areas would be treated as a single “theatre”.
At the same time, Hegseth announced that plans to upgrade the US Forces Japan (USFJ) to a joint force headquarters were now underway, meaning Tokyo would “have more warfighting and operational responsibilities”. The US Defence Secretary further emphasised Japan’s key role in any contingency the United States might face in the region, underlining the goal of maintaining strong deterrence against “the Communist Chinese”.
All of these developments significantly raise the stakes for Seoul – which Hegseth notably skipped during his first Indo-Pacific tour. With the USFJ being given greater autonomy and Japan’s proposal in line with US goals of pooling regional resources to focus mainly on China, USFK and the US military bases in South Korea may soon be pressured to follow suit.
The next South Korean president will have to prioritise the issue once taking office to ensure the country is not dragged into unwanted conflicts, or its security posture jeopardised in any way. With North Korea more emboldened than ever due to its profitable economic and military ties with Russia, Seoul cannot afford to create any potential opening for Pyongyang.
The use of US troops in South Korea to counter China, especially in close coordination with the USFJ, would serve as further propaganda fodder for North Korean leader Kim Jong-un, who would likely claim the move to be yet more evidence of Washington’s “hostile policy”. This would not only invite greater Russian involvement in military cooperation with North Korea, but could also bring Beijing and Pyongyang closer together to counter a growing mutual threat. In other words, a strengthened North Korea–China–Russia bloc could emerge from such changes in the status quo.
The recent developments will impel the next South Korean leader to finalise an agreement to transfer wartime military operational control back to a South Korean commander. If a conflict situation, such as the invasion of Taiwan, were to take place with a US commander still in charge of South Korea’s military during wartime, South Korea could not only be forced into a war against China but also potentially become a sitting duck for a potential attack from Pyongyang.
Moreover, such a change would also present further challenges to inter-Korean relations as it would be seen by Pyongyang as further evidence of Seoul placing Washington’s priorities above those of the peninsula’s long-term stability. In addition, if the United States moved to modernise and upgrade military assets in South Korea to counter regional threats, this would give North Korea further incentive to do the same, possibly with Russia’s help. Denuclearisation would thus remain an elusive goal, further threatening prolonged instability and tensions for the peninsula and wider region.
