Yunzhang Liang | News Contributor
A Ticking Time-Bomb on the Korean Peninsula
On September 9 2024, Robert E. Kelly, professor of international relations at Pusan National University in South Korea, wrote a commentary titled “How long can South Korea resist going nuclear?” He concluded that, depending on US receptiveness to demands for stronger commitments, “South Korea may decide that local deterrence is superior to an uncertain US willingness to risk nuclear devastation on its behalf.”
This was written two months before the 2024 US Presidential elections. Following incoming US president Trump’s win, Kelly published another article, this time conceding that “Trump will almost certainly not carry military costs for (South Korea)” and will “definitely…not carry nuclear risk to the US homeland for them.”
Trump’s upcoming presidency and his previous conduct in foreign affairs could escalate the nuclear debate in South Korea. With Trump as president, US foreign policy will change, and this will perhaps be felt most immediately in places such as Ukraine, China, and the Middle East. The Korean peninsula presents an often-overlooked ticking time bomb, as South Korea grapples with the possibility of building up its own arsenal of nuclear weapons.
Trump: A Turning Point in Bilateral Relations
The US and South Korea share a long history of cooperation and mutual trust. In 1953, following the end of the Korean War, both countries signed a Mutual Defense Treaty. Since then, the US has continually stationed Army, Air Force, Navy, and Marine personnel in South Korea, holding up its promise under the treaty to defend the country against external aggression.
70 years later, in April 2023, US President Joe Biden and South Korean President Yoon Suk-yeol met to address the credibility of US pledges to defend South Korea in the event of a nuclear threat from North Korea. The presidents jointly issued the Washington Declaration, which reaffirmed the US’s “ironclad” commitment to a “swift, overwhelming and decisive response” against any nuclear attack by South Korea’s northern neighbour.
Trump, however, does not view US-South Korea relations in the same way. Prior to the presidential election, he reportedly expressed to his aides in private that he intended to “blow up” the US alliance with South Korea should he be elected for a second term. He has also set a precedent of demanding US allies pay for guarantees of American security and implied that he would do the same with South Korea—a country he referred to as “a money machine”.
Currently, around 30,000 US troops are stationed in South Korea as a deterrent against attacks. Trump, however, who tends to see alliances in transactional terms, has repeatedly said he does not think South Korea is paying enough for these soldiers. He vowed to extract $10 billion a year from South Korea for these troops, more than 9 times its current expenditure of around $1.02 billion. He even claimed that South Korea would be “happy to do it”.
Conversely, Trump built up a curious “bromance” with North Korea’s leader Kim Jong-un, famously claiming in his first term that they “fell in love”. In his acceptance speech this year, Trump added that they “got along very well”: “[Kim] would like to see me back too. I think he misses me, if you want to know the truth.”
This does not bode well for South Korea. Since 2019, Kim has ramped up his testing and production of nuclear-capable missiles. In September this year, North Korea unveiled an unprecedented weapons-grade uranium factory, where Kim vowed to produce “exponentially” more nuclear weapons. Additionally, North Korea currently possesses at least 50 nuclear warheads and intercontinental ballistic missiles (ICBMs) that can strike as far as US soil. This means that the US will be far less likely to engage in a conflict with North Korea, given that US domestic safety is not guaranteed.
What This Means for South Korea
This leaves South Korea with an increasingly hostile neighbour and dwindling prospects of commitment from its US ally. This could lead the nation to favour nuclearisation—though this option is not new to South Korea. In fact, South Korea’s attempt at nuclearisation goes back to 1972, when then President Park Chung-hee authorised a covert military nuclear programme called “Project 890”. The programme eventually fell through due to international pressure and in light of US President Ronald Reagan’s promise to defend South Korea using US troops.
Since then, Presidents in South Korea have been less supportive of nuclearisation, with former President Moon Jae-in dismissing the possibility of domestic nuclear weapons altogether. The biggest shock came in January 2023, when President Yoon suggested that South Korea could develop its own nuclear weapons if North Korea’s nuclear threat grows. This marked the first time since 1991 that a South Korean president officially mentioned the possibility of tactical nuclear weapons in the country. In September 2024, former South Korean defence minister Kim Yong-Hyun also spoke approvingly of the possibility of acquiring nuclear weapons.
In April 2024, a nation-wide poll showed that South Korean support for acquiring independent nuclear weapons capability was 70.9%. While public opinion has favoured nuclearisation since 2010—when surveys of this issue began—the proportion in 2024 was the highest it has ever been. In addition, a majority of respondents also supported reintroducing US-operated tactical nuclear weapons to the Korean Peninsula.
Nevertheless, an investigation conducted by the Associated Press on South Korean public sentiment towards the North revealed that such sentiment is more complex and fragmented than statistics may suggest. While some South Koreans are visibly worried about the threat North Korea poses, others are either resigned to this reality or simply do not believe in North Korea’s capacity to attack the South.
South Korea’s nuclear dilemma is also compounded by its precarious position in the region. It is essentially isolated in northeast Asia and faces three nuclear-armed countries—North Korea, China, and Russia—on its doorstep. It may now have to face these regimes alone if Trump acts the way he did in his last presidency or follows through on his recent rhetoric.
What now?
President of the South Korea’s Institute for National Security Strategy Han Suk-hee said “If the US approves North Korea as a nuclear state in any form, that would be really traumatic for South Korea.” If or when the time comes, South Korea may have to consider guaranteeing its own safety without reliance on foreign alliances, especially with the US, through domestic nuclearisation.
For a while, relations appeared cordial between the US and South Korea. President Yoon “began practicing golf again for the first time in 8 years, in preparation for ‘golf diplomacy’ with Trump,” the South Korean presidential office told CNN. After Trump’s victory, Yoon spoke to him over a 12-minute phone call, during which the pair agreed to arrange an in-person meeting soon. Trump had also expressed the need to continue “good cooperative relations.”
Now, Yoon’s potential impeachment threatens to upend this delicate balance. The political crisis and internal fragmentation will coincide with Trump’s inauguration in January 2025. A weakened South Korean government will be less able to respond to external threats, particularly from North Korea. The government will also find it harder to amass the public support needed to appease Trump. It is, however, too early to tell how this will affect South Korea’s nuclear trajectory in the coming years.
Perhaps the biggest deterrent to a potential nuclearisation effort in South Korea is the fact that it is a signatory of the Nuclear Nonproliferation Treaty (NPT), which bans the country from seeking nuclear weapons. It has the option to withdraw from the NPT in order to develop nuclear weapons, but analysts say this is too risky for South Korea as it could trigger international sanctions.
South Korea currently possesses the capability—the raw materials and equipment—to produce a nuclear weapon. Only time—and perhaps golf—will tell if the nation has the desire to do so.
