Trump can’t denuclearize North Korea. South Korea’s next leader should pursue risk reduction instead

In November 2016, a real estate mogul named Donald Trump defied expectations and won election as the 45th US president. The following month, South Korea’s legislature passed a bill to impeach conservative President Park Geun-hye over a corruption scandal involving her top aide.

History repeats itself: In November 2024, Trump won a second presidential term. About a month later, South Korean lawmakers voted to impeach conservative President Yoon Suk Yeol over a short-lived martial law declaration.

Reactions to Trump’s return were polarized in the United States. Among foreign countries, Seoul’s response was noteworthy. Like other US allies, citizens in South Korea worry about Trump’s remarks calling their country a “money machine” and vowing to make South Korea accept a ninefold increase in defense cost-sharing. On the other hand, South Korean liberals anticipate a renewed dialogue between Trump and North Korean leader Kim Jong Un, which could reduce security tensions on the Korean Peninsula.

Most interestingly, pro-Seoul nuclear armament advocates believe that Trump’s return will increase the chances of South Korea acquiring its own nuclear weapons. They cite a 2016 Trump interview and a more recent interview with Elbridge Colby, who served in Trump’s first administration and is set to serve again in his second term, as evidence of Washington’s openness to allowing Seoul to possess nuclear arsenals as a defense against Pyongyang.

Amid political turmoil in Seoul, proponents of a South Korean nuclear arsenal are unlikely to see their hopes fulfilled during Trump’s presidency, in my opinion. Trump’s transactional approach and his willingness to reengage with Kim Jong Un are likely to instead increase Seoul’s financial burden. Furthermore, Yoon, who is now incarcerated, is likely to be replaced by a progressive leader who is a strong opponent of nuclear armament.

Seoul’s financial burden. Regarding Trump’s transactional approach, he has economic and strategic disincentives to letting Seoul arm itself with nuclear weapons. If Seoul were to do so, its citizens might start to view the expenses for maintaining US Forces Korea—currently agreed to be more than $1.1 billion a year—as unnecessary. They could demand a reduction in US forces or even total withdrawal. Then Seoul would be no longer a “money machine.” Strategically, if the size of the US forces were to shrink, that would weaken US deterrence capabilities against China.

As an alternative, some conservative US Congressmen and security experts have suggested the reintroduction of US tactical nuclear weapons, which were deployed in South Korea during the Cold War, but, given Trump’s transactional approach, he could put a price tag on that. With growing concerns over rising defense costs, the redeployment of US tactical nuclear weapons would pose a significant financial burden on a government that is already experiencing economic instability caused by Yoon’s short-lived martial law.

Trump’s approach to North Korea. With Trump back in the Oval Office, the possibility of resumed nuclear talks between Trump and Kim Jong Un could weaken pro-Seoul nuclear armament groups’ expectations. During the presidential campaign, Trump often boasted about his relationship with Kim and claimed that his first administration had stopped Pyongyang’s missile launches. His current cabinet picks, composed of loyalists, could swiftly proceed with efforts to meet Kim.

As past data indicate, if nuclear talks between Washington and Pyongyang resume, they could reduce Pyongyang’s nuclear provocations, weakening Seoul’s justification for nuclear weaponization.

However, Trump is not in a favorable position for a summit. A few weeks after Trump’s victory, Kim said that South Korea had “already gone as far as we could through negotiations with the [United States],” and reiterated that he was not interested in “uncompromising” US proposals for denuclearization. Kim is in no hurry to meet Trump after having updated North Korea’s nuclear doctrine and capabilities. Moreover, Kim’s recent ties with Moscow have increased the likelihood of further advancing Pyongyang’s nuclear capabilities. Given these complexities, Trump needs new strategies to bring Kim back to the table.

Presumably responding to Kim, Trump called North Korea a “nuclear power” on his inauguration day, as did his new Defense Secretary Pete Hegseth in a written statement submitted during his Senate confirmation process, underlining the Trump administration’s willingness to adopt a pragmatic approach.

This week, a tug of war between the United States and North Korea began. For the first time, North Korea condemned the Trump administration for Secretary of State Marco Rubio’s remark labeling North Korea a “rogue state” and criticized Trump’s plan for strengthening global missile defense. Unlike the war of words in 2017, there has been no direct exchange of criticism between Trump and Kim, which leaves the diplomatic window open.

Public opinion and political parties. Since 2023, opinion polls of South Koreans have shown high support for nuclear weapons development, but the credibility of these polls remains uncertain. In November 2024, then-US Deputy Assistant Secretary of State for Nuclear Affairs Alexandra Bell (who officially became the Bulletin’s president and CEO last week) cautioned that “polls are somewhat framed by the way the question is being asked.” Bell was responding to a Korea Institute for National Unification poll conducted in June 2024, which showed 66 percent support for nuclear armament. As she pointed out, after Trump’s reelection, a poll conducted by the public opinion research agency Media Research showed that more South Korean citizens favored the restoration of relations with North Korea (39.9 percent) than nuclear weaponization (30.8 percent) as a security response to Trump’s second term.

Seoul’s two main political parties have taken contrasting positions over nuclear armament. Key figures in the ruling party, the People’s Power Party, have revealed their openness to acquiring nuclear capabilities. Before a party convention last June, the majority of candidates running for the party’s chief leadership position—who are also likely to be potential presidential candidates if Yoon is impeached—advocated for options such as nuclear armament, nuclear latency (possessing all necessary nuclear capabilities to build a bomb without actually assembling one), and US tactical nuclear weapon redeployment. Among the candidates, Na Kyung-won, a former floor leader of the People’s Power Party, stated that she would push for building a nuclear arsenal as the party’s official platform if elected.

The party’s aspiration for nuclear armament has continued in the aftermath of the US election. Kim Gi-hyeon, a former party leader, proposed a resolution calling for “self-defense nuclear armament.” Once Seoul possesses a nuclear arsenal, he said, its termination would be conditioned on Pyongyang’s denuclearization.

The main opposition party, the Democratic Party, has strongly resisted the idea of possessing a nuclear arsenal, enshrining denuclearization in its party platform. So far, few party members have discussed the possibility of developing a nuclear arsenal, but they have agreed it is unrealistic considering South Korea’s alliance with the United States, the Nuclear Non-Proliferation Treaty regime, and regional stability. The current Democratic Party leader Lee Jae-myung, who has a good chance of becoming the next president, is a strong opponent of nuclear armament, calling it unnecessary, unrealistic, and ineffective in 2023. He reaffirmed his opposition while meeting with the US ambassador to Seoul Philip Goldberg last September.

What Seoul should do instead of pursuing nuclear ambitions. Significant geopolitical change is expected in the region. Along with Trump’s willingness to meet with Kim Jong Un, Japan’s new Prime Minister Shigeru Ishiba openly discussed the establishment of a liaison office in Pyongyang and a summit with Kim after he was elected last October. To avoid being sidelined, Seoul should start to discuss how to restore diplomatic relations with Pyongyang.

Seoul can suggest two adjustments to its approach toward Pyongyang. First, Seoul should propose shifting the direction of Seoul-Washington-Tokyo security cooperation from enhancing deterrence to reducing tensions with Pyongyang. Second, Seoul should propose the restoration of the 2018 Comprehensive Military Agreement, the first implemented arms control agreement between the two Koreas, as a means of reassuring Pyongyang.

With a court ruling on President Yoon’s impeachment trial expected in either late February or early March, risk reduction measures should be discussed within South Korean society and among Seoul, Washington, and Tokyo as soon as possible—before the new administration commences its term 60 days after the court decision.