MAGA Gathers Clouds Over Seoul, Tokyo

Trump’s announced isolationism threatens tripartite security arrangement

By: Shim Jae Hoon

Japan and South Korea, the two principal security and economic allies of the United States in East Asia, are bracing for the inauguration next month of the second Donald Trump administration, which is expected to call for more financial burden-sharing for US troops based in the two countries, and placing crippling tariffs on Asian imports. There are 28,500 US ground troops in South Korea under the mutual defense treaty, and some 50,000 in Japan, also under the mutual defense treaty.

The issue of sharing the cost of their presence has been agreed upon annually. Trump’s demand is expected to generate considerable tension, especially with Seoul, which has just concluded a new agreement with Washington under which it has agreed to pay US$1.1 billion for the 2026 cost of burden-sharing. During his election campaign, Trump has demanded Seoul pay at least nine times more, asserting Seoul is rich enough, and calling South Korea “a money machine.”

The second issue potentially bedeviling the bilateral relations is Trump’s call for imposing 25 percent tariffs on all imports into the US from Mexico. According to industry sources in Seoul, these tariffs could have a powerful impact on Korean goods manufactured in Mexico by South Korean-invested companies. They include Hyundai Motors, Samsung Electronics, and other well-known brands produced by Mexican workers at Korean-invested firms. This issue will be taken up at consultations in Washington, according to local trade officials.

The main political concern, though, rests with Trump’s obsession with resolving North Korea’s nuclear program. South Korean officials are tense over Trump’s boasts during a campaign tour that he could restart talks with North Korea’s dictator Kim Jong Un, who he said remains anxious to see him again. “It’s nice to get along when someone has a lot of nuclear weapons,” he has said. “He would like to see me back, I think he misses me,” Trump claimed. So far, he is the only western leader who has seen and talked with Kim, first at the Singapore summit in 2018 and then at the Hanoi Summit the following year. Those meetings generated a lot of publicity, lifting Kim’s status on the global stage, but no agreement came of it, with Kim refusing to open up his main nuclear facilities for outside inspection.

With Trump’s proven reputation as an unpredictable leader, the likelihood of resurfacing his proposal for a summit talk with Kim Jong Un deeply worries South Korean officials, especially at this time of serious political crisis over President Yoon Suk Yeol’s impeachment on sedition charges. Given his aborted December 3 declaration of martial law, which has now led to his impeachment at the constitutional court, the country is hardly in a situation to undertake prolonged and difficult negotiations with the North. Any prospect of either the US unilaterally or in consultation with Seoul negotiating with North Korea during this period of uncertainty is considered inconceivable. The constitutional crisis in Seoul has practically suspended all serious diplomatic activities.

In Tokyo, the immediate concern is how President Trump would proceed on the issue of ending the Ukraine war, and China’s increasingly frequent military exercises over Taiwan. Japan’s new prime minister Shigeru Ishiba, who took over from former premier Kishida in October, is taking a hard line over China’s frequent military exercises around Taiwan, from which Japan’s territory is separated by just 100 kilometers. Ishiba’s main concerns are twofold: first, North Korean provocations with missile firings over the Sea of Japan, and Russia’s increasingly frequent military exercises over Japan’s northern territory close to the Sea of Okhotsk. In recent days, Russia and China have launched joint military exercises close to the Sea of Japan, raising tensions in Japan but also in South Korea.

North Korea’s decision to send 10,000 combat troops to Ukraine to fight alongside Russian forces amounts to a serious geopolitical provocation, not only in Europe but also in Asia. On the surface, they have been dispatched to Ukraine to acquire combat experience, the first to which they have been exposed since the end of the 1950 Korean War. But the decision involves a dangerous tradeoff, with Russia agreeing to provide missile technology and nuclear submarine production guidance. North Korea’s missile technology is already causing concern, as Pyongyang now is capable of launching intercontinental ballistic missiles capable of reaching the continental USA.

It was against that background that the Biden administration successfully launched a new tripartite security partnership involving Japan and South Korea. At the Camp David Summit in August last year, President Joe Biden took the initiative of bringing South Korean President Yoon Suk Yeol and then Japanese Premier Fumio Kishida for the official launching of the partnership, aimed at developing a common defense against North Korea, China, and Russia. The format helped to bring Kishida with Yoon Suk Yeol into a security arrangement aimed at countering not only North Korea’s ceaseless provocations, but also potential destabilizing actions by other parties including China and Russia. North Korea’s decision to send troops to fight alongside Russian invaders in Ukraine has so alarmed Japan and South Korea that they promptly closed ranks to accept President Biden’s proposal.

The big question facing Seoul and Tokyo now is whether this security partnership will continue under the new Trump administration, whose foreign policy perspectives are essentially isolationist. But in Seoul and Tokyo, this idea of a collective security partnership with the US at the center – if not yet an alliance – makes good sense given the present situation. Constitutionally, Japan remains under its nominally nonmilitary status, although it has developed a powerful self-defense force. With North Korea possessing its own nuclear arsenal, Japan is under pressure to revise its peace constitution which Premier Ishiba is said to be in favor of. Today, Japan implicitly can spend more than 1 percent of its GDP on defense. In recent years, it has exceeded that limit.

Under Biden’s quiet stewardship, the trilateral security format has evolved into a comprehensive and institutionalized body encompassing not only defense but also areas such as the economy, advanced technologies like artificial intelligence and quantum computing. Not only are the three nations sharing strategic information and responses to common threats, but the trio has acquired a physical secretariat in Seoul to align joint responses to threats coming not only from the North, but also from other wider sources.

In the process of developing this security system, the Biden administration can also take credit for bringing Asia’s two historically contentious countries – Japan and South Korea into a common security front. At the Apec Summit in Lima, Peru in November, Biden agreed with Ishiba and Yoon to launch the joint secretariat in Seoul to further serve as a permanent channel for consultation. It has thus become a mechanism to coordinate a joint response to external threats. Ishiba was scheduled to arrive in Seoul in January to formally open the secretariat. With the political situation in Seoul in turmoil, it’s hard to tell if this will take place. But there’s no doubt that this is one of the most important legacies that the Biden administration is leaving behind as he hands over to Trump.