South Korea's Never-Ending Nuclear Weapons Debate | Opinion
South Korean President Yoon Suk-yeol caused a stir in both Seoul and Washington, D.C., last month when he suggested his country could manufacture its own nuclear weapons if the security situation on the Korean Peninsula deteriorated any further. This isn't the first time Yoon has flirted with the nuclear option; during his 2021 presidential campaign, he supported bringing back U.S. tactical nuclear weapons if South Korea's national security was threatened by Pyongyang's nuclear and missile programs.
Yoon's comments generated a diplomatic kerfuffle, forcing him to quickly backtrack on its comments. Still, they were enough to get the Biden administration's attention. In a visit to Seoul last week, Defense Secretary Lloyd Austin reaffirmed the U.S. commitment to South Korea's defense, announced larger-scale joint military drills, and promised more deployments of fighter aircraft to South Korea. Shortly thereafter, U.S. B-1Bs and South Korean F-35s were drilling over the West Sea.
But as North Korea improves its nuclear and missile programs to balance Seoul's superior conventional weaponry, the debate about whether South Korea should join the nuclear club will continue. South Korea has a deep history with nuclear weapons. The United States began stationing nuclear bombs in the South in 1958, four and a half years after the conclusion of the 1950-1953 Korean War. At its peak in 1967, the number of U.S. nuclear warheads on South Korean territory reached 950.
At one time, South Korea also attempted to lay the foundations for its own operational nuclear weapons program. South Korean General Park Chung-hee, who dubbed himself "president for life," had a goal of turning his country into a nuclear weapons power by 1977 and engaged in negotiations with France for a plutonium reprocessing facility. The U.S. intelligence community found out about Park's plans and used significant diplomatic pressure to shut them down. Even so, South Korea continued to work on nuclear technology after Park was assassinated in 1979; according to the International Atomic Energy Agency, South Korean scientists engaged in laboratory experiments involving uranium enrichment as late as 2000.
Ever since the U.S. removed its nuclear warheads from South Korea in 1991, Washington has relied on extended deterrence guarantees to preserve stability on the Korean Peninsula. In essence, the U.S. promises to use all the military power at its disposal, including nuclear weapons, to defend the South in the event of a North Korean attack. The Biden administration has sought to reassure Yoon that this arrangement remains firmly in place, most recently during a September 2022 meeting between U.S. and South Korean defense officials.
Despite those pledges, some doubt the U.S. would follow through. South Koreans today are asking the same question Western Europeans asked during the Cold War: Will Washington defend its allies if it means going to war against a nuclear power and running the risk of a U.S. city being engulfed in a nuclear cloud? An independent South Korean nuclear weapons capability would resolve the quandary. A February 2022 Chicago Council on Global Affairs survey found that 71 percent of South Koreans favor developing their own nuclear weapons.
Popular support, however doesn't necessarily translate into sound policy. Upending the status-quo would be a highly dangerous development with potentially dire security consequences, particularly at a time when Pyongyang and Seoul are already in the midst of an escalatory cycle.

Any South Korean government would rationalize the acquisition of a nuclear weapon as a necessary defensive measure to restore deterrence and warn off potential North Korean aggression. North Korean leader Kim Jong Un, however, is unlikely to view a South Korean nuclear bomb the same way. Instead, Kim, obsessed with his own personal survival and the longevity of his seven decades-long family regime, is more likely to see such a move as an extremely provocative one that aims to dilute the deterrent value of Pyongyang's own nuclear capability. At worst, Kim may even assume that Seoul, in coordination with the U.S., was preparing for military action of its own, with the objective of eliminating the Kim regime for good.
While this sounds farfetched to Americans and South Koreans alike, it's a real world concern for North Korea, a country whose conventional military options are limited in the face of stronger adversaries—including one that happens to be a superpower. Kim Jong Un is a rational actor and will try to offset whatever tactical advantages Seoul may acquire after developing a nuclear weapon. We know this because Kim has already done it; after Yoon stressed that North Korea's political and military leadership would be destroyed if a conflict was deemed imminent, Kim unrolled a new nuclear policy delegating an automatic nuclear attack on the South if Pyongyang's command-and-control system was targeted.
A nuclear-armed South would also ruin whatever slim diplomatic openings exist with the North. Granted, diplomatic openings are essentially nonexistent at the moment—the North Koreans have repeatedly rejected the Biden administration's entreaties over the last two years. Yet if Seoul wielded a nuclear capability, even more reasonable, realistic propositions, like a long-range missile testing freeze, a cap on North Korea's nuclear warheads, or the phased resumption of constructive relations, would be practically impossible to negotiate. The same difficulties would occur if South Korea chose to hold off on assembling its own nuclear weapons and instead requested the redeployment of U.S. nuclear warheads.
What the Korean Peninsula needs above all else is more dialogue, not more weapons. This will require North Korea, South Korea, and the U.S. to begin the process of talking about common-sense risk-reduction measures that minimize the prospects of a war nobody would win at an acceptable price. Otherwise, more tension is a certainty.
Daniel R. DePetris is a fellow at Defense Priorities and a syndicated foreign affairs columnist at the Chicago Tribune.
The views expressed in this article are the writer's own.