Will South Korea go nuclear?

North Korea’s fourth nuclear test in January led to renewed calls in South Korea for the country to build its own nuclear arsenal. Comments by high-profile politicians, conservative media outlets, and some academics are a source of much concern in Washington and the international security community. But these highly publicized, pro-nuclear reactions from a small minority provide a misleading impression of the likelihood that the Republic of Korea will actually pursue its own nuclear capability.

South Korean President Park Geun-hye and other senior officials have firmly rejected the pursuit of nuclear arms and, at least at the present time, few South Koreans believe their country will actually head down the military nuclear path. Nonetheless, even opponents of the nuclear option share much of the frustration and anxiety felt by the nuclear advocates; they believe that there is value in a public discussion of the nuclear weapons issue and warn that, unless Pyongyang’s strategic programs are curbed and the US nuclear umbrella remains reliable, voices urging South Korea to go nuclear will only grow.

To better understand the current debate in South Korea on its future nuclear options, we carried out an extensive series of interviews in April and May with a wide range of prominent South Korean leaders who support and oppose nuclear weapons: incumbent and former senior diplomats and government officials, serving and retired military commanders, National Assembly members in leadership positions, media commentators and editorial writers, leaders and emerging leaders of the business community, experts from South Korean research and academic institutions, and leaders in the South Korean civilian nuclear establishment. This assessment of the South Korean nuclear debate is based largely on those interviews, many of which were conducted on a not-for-attribution basis to encourage candor.

North Korea’s January 6 nuclear test reinforced concerns in the South about Kim Jong Un’s provocative behavior and his apparent intention to maintain and expand the North Korean nuclear arsenal. As was the case following previous North Korean nuclear tests, this one triggered public comments in the South supportive of an ROK nuclear capability. But this time, according to several observers, the comments were stronger and more numerous than in the past. Politicians from South Korea’s ruling Saenuri Party were especially outspoken, with party floor leader Won Yoo-chul, who has become a leading nuclear advocate in the party, asserting in an address to parliament: “We can’t borrow [nuclear] umbrellas from next door every time it rains. We should wear a raincoat of our own.” Saenuri Party members Kim Eul-dong, Kim Jung-hoon (who is party policy chief), Roh Chul-rae, and Hong Jun-pyo voiced similar pro-nuclear sentiments. Former Saenuri Party national assemblyman and former presidential hopeful Chung Mong-joon expressed in a blog post his long-standing frustration with being bound by the Nonproliferation Treaty. The Chosun Ilbo, the leading conservative newspaper, editorialized that “Seoul now faces a real need for public discussion of the development of its own nuclear weapons.” And conservative academic Cheong Seong-chang of the Sejong Institute reportedly asserted, “In the face of North Korea’s growing nuclear threats, [the] time has come for the South to consider the issue of nuclear armament for self-defense.”

Opinion polls released in February appeared to reflect the South Korean public’s concern about the North Korean test. In a poll by the JoongAng Ilbo newspaper, 67.7 percent favored the South having nuclear weapons. A Yonhap News Agency poll reported that figure at 52.5 percent. Such polls have been conducted soon after every nuclear test since 2006 and have consistently shown majority support for nuclear arms.

This flurry of pro-nuclear reactions to the latest North Korean test, however, provides a misleading picture. President Park Geun-hye, Prime Minister Hwang Kyo-ahn, Defense Minister Han Min-koo, and other senior government officials have all strongly and publicly opposed South Korea’s acquisition of nuclear weapons. So have the leading moderately conservative newspaper JoongAng Ilbo, key members of opposition political parties, and prominent experts outside the government, such as progressive Yonsei University professor Moon Chung-in. The Saenuri Party itself is divided on the issue, with influential ruling party officials taking issue with the pro-nuclear views espoused by their colleagues. Ruling Saenuri Party Chairman Kim Moo-sung claimed that advocates of nuclear arms do not have a deep understanding of nuclear issues. He advised us not to “waste any time” on the possibility that South Korea will pursue nuclear weapons and maintained that “there is nothing to worry about.”

Opinion polls showing strong support for nuclear weapons are heavily discounted by many South Korean experts and officials. They argue that, when tensions are high, such as following a North Korean nuclear test, the public will naturally favor the nuclear option, especially if presented only with a simple binary choice between having or not having nuclear weapons. They maintain, moreover, that if a poll builds into its questions some of the expected adverse consequences of going nuclear, support for the nuclear option will drop sharply.

Still, South Korean officials and pundits—including several opposed to an indigenous nuclear weapons program—advise that recent expressions of support for a South Korean nuclear capability should not simply be dismissed as the provocative views of a vocal minority. Those expressions of support, our wide-ranging interviews indicate, reflect deep concerns shared by many South Koreans, regardless of political ideology, and those concerns need to be taken seriously and addressed in Seoul and Washington to reduce the likelihood that the South will pursue a nuclear weapons option.

What motivates recent expressions of support? Recent pro-nuclear comments by politicians, the media, and non-governmental experts are motivated by a wide range of concerns.

Seeking more credible deterrence. At the core of many pro-nuclear voices are doubts about the US nuclear umbrella. For Kim Dae-joong, a senior columnist at the conservative newspaper Chosun Ilbo and longstanding advocate of the nuclear option, an indigenous South Korean nuclear weapons capability is essential to national security because the United States “will not push the [nuclear] button” if the Republic of Korea (ROK) is attacked. Just as France decided that an independent French nuclear deterrent was more credible than a US pledge to put its cities at risk by defending its European allies against Soviet attack, Kim pointed out to us that an ROK nuclear deterrent would be inherently more credible than relying on the US nuclear umbrella. While recognizing that Seoul could pay a very high price politically and economically for going nuclear, he maintains that, if nuclear weapons are considered essential to protecting vital national security interests, South Korea would have no choice but to absorb those costs.

Correcting asymmetry.  For some other South Koreans, an indigenous nuclear capability would serve the important political purpose of correcting a critical asymmetry between the North and South, an asymmetry that places Seoul in a highly disadvantageous position relative to Pyongyang. They told us that such a capability would neutralize the one area of North Korean superiority; force the North to deal with the South more seriously and respectfully; and strengthen South Korea’s bargaining position in any negotiation or confrontation with its northern neighbor. In this view, only by acquiring a countervailing nuclear weapons capability will the ROK have the leverage to negotiate with the North on the reduction and eventual elimination of nuclear arms on the Korean Peninsula.

Pressuring Beijing and Washington. In the case of a significant number of South Korean politicians and pundits, expressions of support for the nuclear option do not reflect a genuine interest in pursuing nuclear weapons, but instead are intended to serve a tactical purpose: Putting pressure on China and, to a somewhat lesser extent, the United States to act with greater resolve to achieve the denuclearization of North Korea. President Park Geun-hye’s substantial investment in improved relations with China and President Xi Jinping has been based heavily on the expectation that it would pay dividends in terms of Chinese willingness to use its leverage to force a change in Pyongyang’s nuclear policies. While China supported tougher sanctions in UN Security Council resolution 2270, South Koreans are disappointed that Beijing has been unwilling to exert decisive pressure against the North, and some believe that the threat of the ROK going nuclear would give China a strong incentive to act more forcefully on behalf of denuclearization. Saenuri Party floor leader Won Yoo-chul asserted in our meeting, “We need to send a clearer message to North Korea. I am discontent with China showing a lack of interest in applying strong sanctions, and instead is exercising too much power [in the region] and interfering with our own affairs, like the deployment of THAAD.” THAAD is the Terminal High Altitude Area Defense anti-ballistic missile defense system that China claims threatens its strategic deterrent.

South Koreans are also disappointed by what they regard as the failure of the United States to give sufficient attention to addressing the North Korean threat. Many believe the United States, in assigning priority to preventing an Iranian nuclear capability, has put the DPRK problem on the back burner. They fear that Washington has abandoned the goal of denuclearization of the North as unachievable and too politically risky even to pursue. For some, public support for an independent South Korean nuclear capability could motivate the United States to re-engage and take a tougher approach, both directly with North Korea and with the Chinese to induce them to apply stronger pressures against the North.

Expressions of support by South Koreans for nuclear weapons are not just aimed at China and the United States. The ROK public is also signaling frustration with its own government. As one senior government official explained to us, “They are asking us [South Korean government] to do something, saying that if we can’t engage [the North to solve the problem], then what’s left is the physical action of going nuclear or not.”

Playing to domestic constituents. In the view of several South Koreans interviewed, the pro-nuclear statements by ROK politicians were less a carefully-considered assessment of the merits of the issue and more a way of demonstrating resolve to their largely conservative constituents in the face of the growing North Korean challenge. For politicians with little to offer in terms of practical proposals for overcoming the threat from Pyongyang, support for the nuclear option was a means of showing that they were “doing something.” One influential pundit, JoongAng Ilbo editor-at-large Kim Young-hie, urged us not to pay attention to statements by politicians, who, in his view, were motivated primarily by a desire to score political points, especially in the run-up to the April National Assembly elections. A National Assembly staff member also confided that pro-nuclear statements by South Korean parliamentarians were often mostly political rhetoric to pressure North Korea and China—not reflective of genuine support for nuclear weapons—and designed to reassure South Koreans that the ruling Saenuri Party was sufficiently and actively concerned by the threat from the North.

Widespread frustration and fear of abandonment. Recent expressions of support for the nuclear option have a variety of specific explanations, as mentioned above. But many of the South Koreans surveyed, whether conservative or progressive, offered an additional and more general explanation, not just for the pro-nuclear statements themselves but also for why those statements may strike a sympathetic chord even among many South Koreans who oppose their country’s acquisition of nuclear weapons. In a word, that explanation is “frustration”—mainly frustration at the failure to rein in North Korea’s nuclear and missile capabilities.

South Koreans had hoped and expected that, with the help of the major powers, especially China and the United States, the North’s strategic programs could be halted and reversed. But now, with North Korean programs advancing and prospects for productive negotiations remote, there is a growing apprehension that the threat may not be reversible. Former Prime Minister Lee Hong-koo, an opponent of nuclear weaponization, explained to us: “It’s an expression of frustration with US and Chinese ambivalence because Korea lost its independence for decades and was forcefully divided, so they [South Koreans] see a lack of responsibility by major powers.”

Moreover, given the widespread perception that China and the United States are not sufficiently committed to dealing with the North Korean threat, South Koreans increasingly fear that they may be left alone to cope with the challenge from the North, and that they will be powerless to meet that challenge. A chairman of a small-to-medium-sized business claimed, “The US can always abandon or sacrifice South Korea for its own interest at decisive moments.”

This fear of abandonment, never far from the surface in South Korea, could lead to efforts to reduce its dependence on the United States for security, and to act more independently and assertively in its own interests. Koreans’ desire for independence from major powers has deep historical roots, dating back to dynastic eras, and it explains arguments such as the following by a South Korean academic: “If we give up securing our own nuclear deterrent for fear of international opposition and depend unilaterally on the United States, we will become nothing but a chess piece manipulated by big powers.”

Despite this frustration with developments in the North, fear of abandonment, and desire for independence, South Korean interlocutors told us that, at least for the time being, these widespread feelings were unlikely to lead to a decision to acquire nuclear weapons.

The recent up-tick in pro-nuclear statements can be attributed significantly to motivations other than the actual desire to acquire nuclear weapons, including motivations of a tactical, political, and even emotional character. The tentative and qualified nature of support for the nuclear option can be seen in what nuclear advocates are actually calling for. Few, if any, ask the ROK government actually to embark on a nuclear weapons program in the near future. The most forward-leaning of the advocates call for “consideration” of a nuclear weapons program, the acquisition of civil enrichment or reprocessing facilities as a hedging capability that would provide a future option to pursue nuclear weapons, or the return of US tactical nuclear weapons to South Korea. More restrained ideas include temporarily withdrawing from the Non-Proliferation Treaty, declaring invalid the North-South denuclearization agreement of 1992, and warning the North Koreans that, unless they agree to abandon their nuclear program, the ROK may embark on its own or the United States may bring back its tactical nuclear weapons.

In sum, extensive interviews with prominent South Koreans indicated that, despite recent public statements and polling results, genuine support for ROK acquisition of nuclear weapons remains very limited and confined to a vocal minority with little or no influence over national policy decision-making.

Opposition to nuclear weapons in South Korea remains strong. In response to recent public comments supportive of nuclear weapons, ROK officials as well as a broad spectrum of non-governmental South Koreans have reaffirmed their opposition to the nuclear path. When asked about the possibility of the ROK pursuing a nuclear weapons capability, a senior South Korean military official asserted: “For certain, that will not happen.” The head of JoongAng Ilbo’s editorial board, Lee Ha-kyung, maintained that a nuclear weapons program would “throw South Korea into the Stone Age” by undermining its reputation as a champion of nonproliferation, making it impossible to press for North Korean denuclearization, precipitating the departure of US forces, and damaging an economy heavily dependent on international trade. Saenuri Party Chairman Kim Moo-sung, an apparent presidential hopeful, expressed similar views to us, asserting that South Korea would be “slapped with sanctions” and its heavy reliance on nuclear power would end due to a cut-off of foreign nuclear fuel supplies.

Senior officials in South Korea’s civil nuclear energy establishment emphasized to us the dramatic impact on Seoul’s ambitious nuclear energy plans if a decision were made to acquire nuclear weapons: Its plans to boost reliance on nuclear power to generate electricity, to become a major nuclear exporter (and complete its major reactor project in the United Arab Emirates), and to cooperate with foreign partners, including on advanced research and development, “would all go down the drain.” One senior civil nuclear energy official supported South Korea’s pursuit of a pyroprocessing capability, but only for strictly peaceful purposes, and said he complained when Korean politicians called for acquiring such a dual-use nuclear capability for national security reasons. (Pyroprocessing is a method for processing spent nuclear reactor fuel that South Korean scientists argue is proliferation-resistant and will help solve their looming spent fuel storage crisis. The US government sees pyroprocessing as a potential proliferation risk, but the new US-South Korea civil nuclear cooperation agreement reached in 2015 contains pathways for Washington to grant permission for pyroprocessing, after a thorough examination of the technology.)

Although some ROK nuclear advocates have held that the United States would acquiesce in South Korea’s acquisition of nuclear weapons and maintain its forces on the peninsula, former Foreign Minister Song Min-soon argued that the presence of US forces in South Korea was incompatible with Seoul becoming a nuclear power. In our meeting, he noted that, in the cases of Israel and India, the United States has tolerated their nuclear programs but pointed out that the United States does not have formal alliance relations with either of those countries, binding security commitments, or a significant troop presence—all of which are critical to South Korean security but would be terminated by Seoul’s acquisition of nuclear arms.

While several South Koreans interviewed argued that an ROK nuclear capability was incompatible with existing US-ROK alliance arrangements, a senior government official suggested that it was also incompatible with the goal of reunifying the peninsula, saying, “If we want unification, we have to denuclearize. If we’re asked if we want unification or nuclear weapons, we’d undoubtedly want unification.”

A small business owner and some future leaders of South Korean corporations and conglomerates (“chaebol”) expressed to us that a South Korean nuclear weapons program would be very damaging politically and especially economically, maintaining that the chaebols and other large companies are against the nuclear option. They personally questioned the reliability of US security commitments, but felt South Korea had no choice except to rely on the United States for its security. The head of a large conglomerate saw the political utility of nuclear-weapons rhetoric in persuading China to rein in the North, but was also mindful of Beijing’s reaction; he noted that Korean businesspeople are concerned that one comment from China on THAAD can affect the stock market and the Korean economy. The chairman of a small/medium-sized company saw some advantages in the South’s possession of nuclear weapons but believed that China and the United States “would not allow” that to happen and claimed that possessing a latent nuclear capability would be a sufficient deterrent.

Several of the interviewees gave another reason for not believing Seoul would opt for nuclear weapons: The South Korean public—especially the younger generation, whose main priority is personal financial success—had grown accustomed and even inured to the North Korean threat and would not consider it necessary to counter the threat with an indigenous South Korean nuclear program, especially if it meant sacrificing their comfortable lifestyle.

The US nuclear umbrella in an uncertain strategic landscape. The key to maintaining support in South Korea for its non-nuclear status, especially in the face of an unconstrained North Korean threat, is confidence in the reliability of US security assurances. As long as ROK policymakers and public regard the US nuclear umbrella as effective and dependable, incentives will remain low for seeking an independent nuclear deterrent.

Most South Koreans told the authors that they trusted the United States to stand by its commitments to ROK security, at least at the present time. They praised US support for efforts to deter and respond to further provocations from the North; welcomed strong public affirmations of US commitments by President Obama, Defense Secretary Ash Carter, and other senior US officials; acknowledged the deterrent value of recently conducted, large-scale joint military exercises; and, in a number of cases, asserted that the US-ROK alliance has never been stronger.

But a significant number of interviewees indicated that they had questions and concerns about the future. Donald Trump came up in almost every conversation. His threat to withdraw US forces if South Korea did not provide adequate compensation for their presence was unnerving and reminded some of President Jimmy Carter’s 1976 presidential election campaign pledge, later reversed, to withdraw US ground troops from the peninsula. Even if Trump does not become president, the unexpectedly strong support he received in the Republican primaries has reinforced worries in Seoul that the public mood in the United States is becoming more isolationist.

The National Assembly Foreign Affairs and Unification Committee Chairwoman Na Kyung-won(of the ruling Saenuri Party) expressed to us concern that possible future negotiations with North Korea on a peace treaty to replace the 1953 armistice agreement could result in the withdrawal of US forces from South Korea. Na also worried that wartime operational control of ROK forces might be transferred from the United States to South Korea without the latter having made sufficient preparations to ensure effective deterrence. She did not believe the case for ROK nuclear weapons was strong but nonetheless maintained that, given these and other uncertainties about the future strategic environment, South Korea’s nuclear options should be kept open.

The potential vulnerability of US territory to attack by a North Korean nuclear-armed, long-range missile was also on the minds of South Koreans. The concern expressed by some defense analysts, former military officers, and pundits: The United States might be reluctant to employ nuclear weapons in response to a North Korean nuclear or massive conventional attack against the South for fear of nuclear retaliation by Pyongyang against the American homeland—in other words that, at a decisive moment, Washington would sacrifice South Korea to protect its own territory. The advent of US vulnerability could exacerbate a concern in South Korea that the United States is reducing the role of its nuclear weapons, whereas some ROK strategists would like to see nuclear weapons play a key, if not larger, role in Korean Peninsula contingencies. One veteran journalist—JoongAng Ilbo editor-at-large Kim Young-hie—estimated that North Korea might be three to five years away from having the capability to strike the United States with nuclear-tipped missiles. He warned that, unless the United States and the ROK used this “grace period” to reinforce their combined deterrent capability, support for an independent ROK nuclear capability would increase.

Several South Koreans interviewed did not believe North Korea’s ability to reach the United States with nuclear weapons would necessarily be a game changer. A former ROK military commander and Chairwoman Na both expressed confidence that Washington would honor its commitments despite the vulnerability of its territory. They acknowledged that, during the Cold War, America’s NATO allies found the US nuclear umbrella credible even though US territory was vulnerable to nuclear attack from the Soviet Union, whose nuclear arsenal was many times more powerful than that of North Korea. Still, they believed that, to ensure the credibility of the US nuclear umbrella in the face of further advances in North Korea’s strategic capabilities, it was essential to continue working to strengthen the extended deterrent.

Reinforcing the US extended deterrent. For many South Koreans, there is no contradiction between having full confidence in US willingness to meet its alliance commitments and, at the same time, believing that the US extended deterrent could and should be strengthened. Time and again, South Koreans told the authors they did not doubt US assurances but, when pressed, expressed the view that there was room for improvement in the extended deterrent. A former senior military commander told us he was “100 percent confident” in the alliance but felt that the Korean public did not share his view and that further efforts needed to be made to reassure it. A senior government official also explained that there were suspicions and doubts in South Korea about whether the current “tools of deterrence” were sufficient, but stressed that that did not mean there were doubts about the alliance.

In our interviews, ROK policy-makers and well-informed non-governmental observers, not just the general South Korean public, saw highly visible indicators of US support as critical. Sending B-52 bombers from Guam to fly over South Korea just days after Pyongyang’s January nuclear test was intended as much to show solidarity with South Koreans as to deter the North Korean regime. Similarly, a retired military commander told us that the Key Resolve and Foal Eagle joint military exercises in March-April 2016—the largest joint exercises since 2010, featuring more than 15,000 US personnel—were tangible demonstrations of allied commitment. And although the deployment of the THAAD missile defense system—which both countries announced in July—is controversial in South Korea, particularly in light of Chinese efforts to derail it, THAAD is also intended to reassure South Koreans of US determination to provide protection against the North.

In the view of South Koreans we interviewed, such highly-publicized actions—together with strong declarations of support by the American president and US military commanders, frequent visits by senior-level US officials, and other gestures and symbols of commitment—can go a long way toward convincing America’s vital East Asian ally that it can count on the United States.

A vocal minority believes that the return of US tactical nuclear weapons to the Korean Peninsula could be another tangible, high-profile form of reassurance. This camp maintains that the reintroduction of tactical nukes would send a powerful deterrent message to the North, demonstrate a strong commitment to the South, and provide a bargaining chip to achieve denuclearization of the peninsula. One expert asserted that South Korean interest in redeploying US tactical nuclear weapons should be regarded as an indication that South Koreans are comfortable continuing to rely on the US nuclear umbrella and that they do not want to develop their own nuclear weapons.

In addition to public demonstrations of support, the United States needs to offer reassurance at the more discreet level of interactions between the US and ROK policy-making and strategic communities. Many of those interactions now take place in the bilateral Defense Strategy Committee (DSC)—an official, expert-level consultative body that operates under the ministerial-level Security Consultative Meeting (SCM) led by South Korea’s Ministry of National Defense and the US Defense Department.

South Koreans familiar with the proceedings of these bilateral exchanges told us that these detailed and highly professional interactions have come a long way in a short period of time, helping to build a better common understanding of extended-deterrence issues. South Korean experts and policymakers clearly place a high value on the opportunity to discuss sensitive security matters with their American counterparts. But several whom we interviewed did not hide their belief that, at least so far, the United States has not been forthcoming enough in sharing information about US nuclear plans or in providing the ROK a meaningful role in operationalizing the extended deterrent.

One well-connected analyst, Asan Institute for Policy Studies vice president Choi Kang, claimed that the United States is often unresponsive to ROK requests for information about US deterrence planning and operations. He said the overall US approach to South Korea on such matters is, “Don’t worry, trust us, we’ll protect you.” According to him, South Koreans are concerned that a US preference in certain circumstances to respond to a North Korean nuclear attack with conventional means, like precision-guided munitions, may reflect a US reluctance to use nuclear weapons in defense of South Korea. He also held that South Korea wanted US-ROK collaboration on extended deterrence to emulate the very close cooperation assumed to take place in the NATO Nuclear Planning Group, where US non-nuclear weapon state allies are involved in planning for the use of US nuclear weapons. But he stated that the United States had rejected the use of the NATO model for South Korea.

The authors heard similar views at a meeting with a group of strategic analysts at a defense-oriented research institute. Their biggest complaint was that the United States did not share enough information in the Defense Strategic Committee process, including information on plans for redeploying US strategic assets to South Korea in a crisis or plans for using nuclear weapons. They also expressed an interest not just in getting briefed on US nuclear plans, but also in participating in the development of joint operational plans, which, among other things, could include ROK input into the selection of targets. The experts said the US response to South Korean requests for a greater say in US nuclear operations was that the American president has exclusive authority over the use of US nuclear weapons—they are “the president’s nuclear weapons,” they were told—and this authority could not be shared.

The analysts expressed concerns about the potential future “de-coupling” of the US deterrent—the idea that, if and when US territory becomes vulnerable to North Korean nuclear attack, Washington would become reluctant to come to the defense of South Korea. Therefore, although they did not support an indigenous ROK nuclear weapons capability, they favored consideration of steps to reinforce the US extended deterrent. Those reinforcements could include stationing US nuclear-capable aircraft in South Korea and planning to bring US nuclear weapons to the peninsula in a crisis—or perhaps even stationing US nuclear weapons there permanently.

It is natural that mid-level experts who specialize in deterrence issues would identify potential deficiencies in current arrangements and favor measures to shore up and enhance deterrence. But the authors found that the experts’ concerns and some of their remedies were shared by senior military officers, both active duty officers and former commanders, although their reservations were often expressed in a more guarded and nuanced manner.

While praising the work of the bilateral consultative process, one retired military commander told us the process had not kept pace with advances in North Korean strategic programs. A senior South Korean administration official close to these issues also said he recognized there are secrets the United States cannot disclose, but he nonetheless felt transparency could be greater, noting that Washington had yet to provide a briefing on operational plans. A retired senior military officer maintained that those who are aware of the details of the extended-deterrence dialogue feel secure, but that many South Koreans “need more proof that the US will be there for us.”

US officials acknowledge that ROK experts are pushing for more. Several Americans currently or formerly involved in bilateral extended-deterrence consultations confirmed that, in the Defense Strategic Committee and in semi-official discussions on the margins of DSC meetings, South Korea has persistently called for more information about US plans and a greater role in the planning process. The South Koreans, according to the Americans, have “pressed the envelope,” seeking the joint development of detailed operational plans for responding to a wide range of contingencies.

An American official involved in the DSC process told us that the United States already engages in more detailed discussions with the ROK regarding the US nuclear umbrella than with any other ally. Acknowledging that the South Koreans have called for a joint planning mechanism along the lines of the NATO Nuclear Planning Group, another American official said that US DSC participants have explained to their South Korean counterparts that Seoul has an inflated view of what takes place in the NATO planning body, but the Koreans seem to doubt such explanations and continue to raise the issue of a bilateral planning mechanism.

Current and former US officials acknowledge that their ROK counterparts have not been fully satisfied with bilateral consultations on extended deterrence, but believe that some of their frustration is unavoidable. While South Koreans may want joint decisions on “what to strike, when to strike, and how to strike” targets in the North, the American officials point out what they have often told the Koreans—that the authority to employ “the president’s nuclear weapons” cannot be shared. And while Seoul may seek agreed contingency responses to a wide range of conceivable North Korean provocations, Washington is reluctant to limit its flexibility to tailor its responses to the particular circumstances of each case.

Despite certain limitations on what can be done jointly and somewhat differing approaches toward planning, the bilateral consultative process has been fairly successful in providing South Korean policymakers and experts a greater window into the operation of the US nuclear umbrella and a greater voice in shaping the US-ROK combined deterrent. Given their dependent position and the huge stakes involved, it is inevitable and understandable that South Koreans will always push for more—more transparency, more participation in planning, more control over the factors affecting their vital security interests. But notwithstanding ROK interest, especially at the expert level, in further strengthening the components of deterrence, the prevailing view among South Koreans, at least for the time being, is that they can continue to rely on security assurances provided by their major ally.

The need for reassurance. The wide-ranging interviews we conducted tended to confirm the view that recent public expressions of support for reconsidering ROK nuclear options do not reflect a strong South Korean interest in actually pursuing nuclear weapons. Indeed, despite deep concerns triggered by North Korea’s apparent determination to move forward with its nuclear and missile programs, the vast majority of South Koreans appear to remain committed to a policy of nuclear forbearance.

Two interrelated factors will be the key determinants of whether South Korea will remain on its non-nuclear course. The first is North Korea. If Pyongyang’s strategic programs can be reversed or significantly contained, the possibility that Seoul will opt for nuclear weapons will become even more remote. But if the North’s programs continue to advance, and especially if they are accompanied by belligerent North Korean behavior, support for an independent ROK nuclear weapons capability will grow. Therefore, to reduce incentives for America’s East Asian allies to pursue nuclear weapons, to diminish the likelihood that other countries will seek to follow North Korea’s nuclear playbook, and to reverse the North’s threat to the security of the United States and its allies, the next US administration will need to make North Korea one of its principal national security preoccupations.

The second factor is confidence by South Korean policymakers and public in the reliability and effectiveness of US security assurances. Today, that confidence is relatively high, particularly among ROK elites. But many South Koreans, including those who do not now doubt US dependability, have questions about the future. They are concerned about uncertainties in the strategic landscape—whether the American public will remain fully committed to the alliance, whether possible peace negotiations with North Korea or impending changes in alliance command arrangements will weaken deterrence, and whether the possible future vulnerability of US territory to a North Korean nuclear attack will reduce American readiness to come to South Korea’s defense. Given these uncertainties, even some South Koreans who currently oppose an indigenous nuclear weapons program believe it is only prudent to keep their country’s future nuclear options open.

If authorities in Washington and Seoul want to keep incentives and pressures for an ROK nuclear weapons capability low, they will have to give high priority to reassuring South Koreans that they can count on the US extended deterrent. That will require frequent and highly visible demonstrations of commitment, including high-level statements of support by American officials, joint exercises to show collective resolve, and tangible indications—such as B-52 and B-2 flyovers—that US strategic assets remain at the disposal of the alliance.

Reassurance will also require addressing concerns raised by South Korea’s strategic community about the sharing of information and the role of the ROK in extended deterrence. In the past, most South Koreans were content to leave the job of nuclear deterrence to the United States. For a growing number, especially within the strategic community, that is no longer the case. Fearful of abandonment by the major powers and chafing at continued dependence on the United States, an increasing number of South Koreans would like to see their country playing a more assertive, independent role, and this is reflected in efforts by South Korean experts and policymakers to make the ROK a more co-equal partner in deterring North Korean aggression.

Especially if North Korean strategic capabilities continue to advance, South Koreans will push harder for that more prominent role. While there have been good reasons for resisting some South Korean requests for more information-sharing and greater participation in nuclear decision-making, it will be important in the future for the United States to find ways of accommodating ROK interest in making a more substantial contribution to their combined deterrence, while at the same time preserving the US president’s nuclear prerogatives and flexibility to adapt to a wide range of contingencies. The allies will need to consult closely on such critical deterrence issues as where to deploy, and how and when to re-deploy, US strategic assets, including nuclear-capable aircraft and even nuclear weapons. While ultimately such decisions will be made by the United States, it is essential that they fully take into account ROK perspectives on how best to ensure an effective deterrent.

There will naturally be resistance in Washington to giving South Korea a more influential role on key deterrence questions. But if the choice is between accepting such a role and watching as South Korean support builds for an independent nuclear weapons capability, it should be clear which is the better course.

As a vibrant democracy, South Korea should and inevitably will have a dynamic debate on its future nuclear options and on how those options affect its number one national security concern. There will always be proponents of acquiring nuclear weapons in South Korea. The international community should not, however, overreact to these voices. They remain a distinct minority. Decision-makers and the permanent bureaucracy, as well as most South Koreans outside government, are well aware of the adverse consequences of going nuclear. But the South Korean public could wind up strongly resenting constant warnings of such consequences from the outside, particularly if offered by American officials; such repeated warnings could be seen as attempts to exert pressure and constrain the ROK’s choices. In any event, the warnings are probably unnecessary. Left to their own devices, South Koreans are unlikely to opt for nuclear weapons.

But Seoul’s continued nuclear abstinence cannot be taken for granted. To keep the probability of a nuclear-armed ROK low, the United States will have to make curbing North Korea’s strategic programs and reassuring its ally about the reliability and effectiveness of its nuclear umbrella key components of US policy in the years ahead.