The third nuclear test conducted by North Korea on February 12 was the latest in a long history of provocations. In many capitals, this event was noted with some alarm and then more or less pushed aside by other issues. Not so for denizens of the southern half of the Korean Peninsula. There, the North's nuclear test was so threatening that it has moved onto center stage a once-fringe debate about whether South Korea should acquire nuclear weapons of its own. Washington and Beijing should take notice. 

Public opinion polling in South Korea over the last decade has consistently demonstrated majority support both for an indigenous nuclear weapons effort and the return of US tactical nuclear weapons, which Washington withdrew in 1991. In two recent polls conducted in the wake of the North Korean test, 64 percent and 66 percent of those surveyed agreed that South Korea should possess its own nuclear weapons. This is not surprising as a simple matter of equality with North Korea, ignoring for a moment the thorny technical and policy issues that developing nuclear weapons would pose to South Korea. Public opinion seems to reflect a general sense of insecurity among South Koreans more than a real desire that their government build nuclear weapons.

Toby Dalton
Dalton is the co-director and a senior fellow of the Nuclear Policy Program at the Carnegie Endowment. An expert on nonproliferation and nuclear energy, his work addresses regional security challenges and the evolution of the global nuclear order.
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Elite opinion until now has largely discounted nuclear weapons. The issue resonated only at the political fringe, where a few conservative politicians and commentators periodically voiced support for nuclear weapons. In a 2011 Chosun Ilbo column, for instance, Kim Dae Jung, the conservative commentator and political analyst, argued: "Only when Seoul develops a nuclear bomb will the way for substantive negotiations between the two Koreas open. We can no longer entrust our lives and territorial security to the incompetence of world powers that have failed to settle the North Korean nuclear issue for over two decades."  

The North's February test broke the taboo and brought the nuclear issue into mainstream political discourse; more commentators and politicians have joined the debate. Anti-nuclear arguments still seem to dominate, but more people are now willing to argue in favor of nuclear weapons in South Korea. Because the debate is new, the various strands of argument are not yet fully formed. The boundaries between these strands are still squishy, with many protagonists present multiple arguments that are not mutually exclusive. Our review of publicly available Korean and English-language reporting to date suggests the following four (and maybe more) separate arguments in favor of South Korean or US nuclear weapons.  

Return US tactical nuclear weapons to improve bargaining leverage with North Korea

By this logic, redeploying US tactical nuclear weapons would force North Korea back to negotiations culminating in the dismantling of its nuclear weapons program. One proponent of this view, Jeon Sung Hun, senior researcher at the Korea Institute for National Unification, has argued that US tactical nuclear weapons could be used in a strategy of "bilateral denuclearization" with North Korea. Echoing this view, Won Yoo Chul, former chairman of the National Defense Committee, asserted two days after North Korea's third nuclear test, "It is time to consider the necessity of redeploying US nuclear weapons, based on the premise that we would abandon these weapons immediately once the North Korean nuclear issue is solved."

Redeploy US tactical nuclear weapons to enhance deterrence against North Korea

The latest North Korean test played on Korean fears about the durability of the ROK-US alliance and the reliability of US extended deterrence commitments. Some Koreans worry that without its own nuclear weapons on the Peninsula the United States might give in to nuclear coercion by Pyongyang at South Korea's expense. The return of US tactical weapons would thus "fix the torn [nuclear] umbrella," according to Chung Mong Joon,* member of the Korean National Assembly and former chairman of the ruling Saenuri party. "At a time of crisis, we are not 100 percent sure whether the Americans will cover us with its nuclear umbrella," he argues. Suggesting a similar logic, albeit without physically stationing tactical nuclear weapons on South Korean soil, Kim Young Hee of Joongang Ilbo posited that "The only remaining way to solve the North Korean nuclear problem is to enforce nuclear deterrence. The best way is to deploy US nuclear-armed submarines regularly under the East Sea and observe North Korea's behavior."

Develop South Korean nuclear weapons to alter calculus in North Korea nuclear negotiations

Those convinced that the redeployment of US tactical nuclear weapons is insufficient leverage against North Korea argue that indigenous South Korean nuclear weapons could achieve a better result in negotiations. An ROK nuclear weapons program would pressure China and the United States to bring North Korea to the table to achieve denuclearization. This view was espoused by Lee Chun Geun of the Korea Economic Research Institute: "When we solidify our resolution to develop our own nuclear weapons, the US, China, and Russia cannot help but look for a practical way to hold back North Korea's nuclear weapons." Chosun Ilbo reporter Jung Kwon Hyun similarly stipulated that only the fear of other East Asian "nuclear dominos" like Japan and Taiwan would convince China of the need to rein in North Korea's nuclear behavior.  

Develop South Korean nuclear weapons as a security guarantee

"If North Korea possesses long-range missiles that can attack the state of the US, one might consider the US nuclear umbrella to be torn. Will the US be prepared to sacrifice Los Angeles to save Seoul?" queried Lee Chun Geun. For those who worry that the answer to this question is "no," then South Korea can only rely on its own capabilities. Nuclear weapons would provide South Korea with a means of self-defense independent of the United States. One proponent of this view, the conservative commentator Jeon Won Chaek, argued that "we have to be nuclear armed ourselves to survive."

The fact that this debate has emerged from the shadows does not make a South Korean decision to pursue nuclear weapons any more likely. There are just as many, if not more, arguments against nuclear weapons, ranging from the economic and reputational penalties that would result from violating the Nuclear Non-Proliferation Treaty to legitimizing North Korea's nuclear weapons. Indeed, the ROK government has taken pains to distance itself from pro-nuclear weapon views. Chun Young Woo, presidential secretary for foreign affairs and national security, stated on February 20, 2013, that "The government has never considered such an [indigenous nuclear weapon] option, nor is it something to be considered." Defense Ministry spokesman Kim Min Seok similarly stated on Feb. 15 that Korea "is not considering bringing in tactical nuclear weapons right now because the priority is to make North Korea give up its nuclear armament."  

For now, the United States and China can observe the discourse and seek to better understand the sources of concern that lead to arguments in favor of nuclear weapons in South Korea. It is too early for Washington to consider additional ways to bolster US extended deterrence and reassurance commitments, but that time may come soon if and when North Korea makes new provocations. Beijing has a strong interest in preventing escalation of tensions and presumably has steps it could take to encourage North Korean restraint. In the end, the fact of the ROK nuclear debate, rather than its content, may lead to some policy changes in the region. But the arguments in favor of nuclear weapons point to growing insecurities in Seoul that should not be ignored.  

* Note: Chung Mong Joon will deliver a keynote address on this issue at the 2013 Carnegie International Nuclear Policy Conference, April 8-9 in Washington, DC.

This article was originally published by the Pacific Forum CSIS.