Dr. Seong-Chang Cheong: The Case for South Korean Nuclearization, Part III
How South Korea’s Nuclearization Will Actually Strengthen U.S.-ROK Ties
Introduction by Mitch Blatt: Dr. Seong-Chang Cheong, the Director of Department of Reunification Strategy Studies at the Sejong Institute, has been a Lecturer at Seoul National University, a Policy Advisor for the Ministry of Unification, the Joint Chiefs of Staff, and the Office of National Security, and a Guest Commentator for the Korean Broadcasting System (KBS). He is an advocate for South Korea’s indigenous development of a nuclear weapons program. He argues that the ROK’s nuclearization would enhance Korean national defense and take pressure off the United States and could compel North Korea to the negotiating table. He has provided me a paper he wrote on the issue in December 2022. I will be publishing the paper this week in three parts. In Part II, Cheong proposed a five-stage strategy for denuclearization of North Korea. Now, in the final installment, Part III, Cheong explains how South Korea’s nuclearization could actually strengthen U.S.-Korea ties.
Text by By Seong-Chang Cheong
Ⅴ. Is South Korea’s indigenous nuclearization the “worst possible option” for the ROK-US alliance?
In South Korean and the U.S. media outlets, we often see the articles written by the experts opposing South Korea’s indigenous nuclearization. However, the voices supporting the idea have also been heard in Washington. Since around North Korea’s third nuclear test on February 12, 2013, shortly after Kim Jong Un came to power, voices have been raised in the U.S. calling for considering building up South Korea’s own nuclear capability. John Mearsheimer, one of the most influential realist international relations scholar and professor at the University of Chicago, estimated that “there is little doubt that North Korea is now a nuclear-armed state” in an interview with the Korea Joongang Daily published on February 22, 2013.[6] He also posed a question, “Would any American president use nuclear weapons to protect South Korea or Japan When the United States’ own survival was not at stake and when nuclear war might actually threaten America’s survival?” and indicated that “this thorny question gives both South Korea and Japan powerful incentive to acquire their own nuclear weapons.” He added that deployment of tactical nuclear weapons or South Korea’s acquisition of its own nuclear weapons should be remained as possible options.
In April 2015, Charles D. Ferguson, then president of the Federation of American Scientists, analyzed the possibility of South Korea’s indigenous nuclearization in detail in his report titled “How South Korea Could Acquire and Deploy Nuclear Weapons,” which was circulated off-the-record to a group of non-proliferation experts. In this report, Ferguson pointed out, “Many experts believe that South Korea, one of the stalwart defenders of the nuclear nonproliferation regime, is not likely to develop its own nuclear arsenal, especially with the provision of the U.S.’ nuclear deterrence commitments. However, with the worsening security environment in Northeast Asia, the ROK may consider developing nuclear weapons under serious threat to its national security.” He also estimated that “the currently stockpiled spent fuel at the dry cask storage facility at Wolsong could provide about 26,000 kilograms of reactor-grade (as of the end of 2014), but still weapons-usable, plutonium for South Korea,” and with a conservative estimate of about six kilograms plutonium for a first-generation fission device, “the ROK has up to 4,330 bombs’ worth of plutonium at this site.”
This report also says, “Depending on how the security environment unfolds in Northeast Asia, the United States might, behind closed doors, welcome Japan and South Korea developing nuclear weapons. While this would be a huge blow to the nonproliferation regime, Washington might have little choice in its Northeast Asian allies taking such a drastic action if North Korea further advances its nuclear capabilities and if Seoul and Tokyo have governments that cannot tolerate increasing vulnerability.” Ferguson added, some argue the Korean economy would suffer in case of nuclearization due to the resulting international sanctions, but the sanctions is not likely to last long, considering the precedent of India, which conducted nuclear explosive tests in 1998.
He anticipated that South Korea’s withdrawal from the NPT could lead to international sanctions but no severe ones—especially on nuclear exports. Harsh sanctions will also hurt the economy of other countries such as the U.S., France, and Japan, countries which would benefit from the partnership with the ROK in the nuclear industry.
Following North Korea’s fourth nuclear test in 2016, American politicians also began to positively consider South Korea’s nuclearization. Then-U.S. Republican presidential nominee Donald Trump said he would allow South Korea and Japan to develop their own nuclear arsenal, instead of depending on the U.S.’ nuclear umbrella, to protect themselves from North Korea and China. He also added that Japan and South Korea would want their own nuclear weapons in any case if the present weakness of the United States continues. Trump also insisted that the U.S.’ allies such as Korea should be responsible for their own security issue by building their own nuclear arsenal if they do not bear the entire cost of the U.S.’ military presence.
On March 16, 2021, during a webinar co-hosted by Washington Times and International Association of Parliamentarians for Peace (IAPP), U.S. Representative Steve Chabot, a Republican ranking member on the subcommittee on Asia and the Pacific of the House Foreign Affairs Committee, pointed out that it is nuclear-armed Korea and Japan which will intimidate China into staying awake during the night, and that this issue needs to be discussed in a serious manner. He further explained that he did not mean that the U.S. should help them to acquire nuclear weapons, but it should have serious conversations with the two partners in this regard.
On September 15, 2022, the Representative Steve Chabot met Thae Yong-ho, the ruling People Power Party’s member of the national assembly, during Thae’s visit to the U.S. At the meeting, Chabot indicated that it is imperative to make China put pressure on North Korea to be back to the negotiating table, and to this end, it is also essential to show that the U.S. is discussing nuclearization with the South Korea and Japan. He reiterated that there is no possibility to bring North Korea back to the denuclearization talks in a situation where North Korea’s nuclear buildup is tolerated and even the support to North Korea in the form of military and economic aid continues. He also asserted that South Korea and Japan have right to consider nuclear armament when North Korea continues to threat with its nuclear weapons.
Over the past two years, a number of experts’ contributions, arguing that the U.S. administration should accept the South Korean government’s decision if it decides to go nuclear, continue to be published in the media and specialized academic journals, such as the Washington Post, Foreign Policy, The Diplomat, and The National Interest.
Moreover, as examined above, the former U.S. President Donald Trump, the Republican ranking member on the subcommittee on Asia and the Pacific of the House Foreign Affairs Committee, and many other prestigious scholars and experts, have expressed positive views on the nuclearization of South Korea. Therefore, the assertion of some experts that the U.S. will “never” accept Seoul’s nuclear weapons development is unreasonable.
Some American experts argue that Seoul’s nuclearization will undermine the ROK-U.S. alliance. However, such an argument is totally ungrounded if we look at the poll results from South Korea. According to the “Unification Perception Survey 2022” published on September 22, 2022, by the Institute for Peace and Unification Studies (IPUS) at Seoul National University, to the question “Which country do you feel closest to?”, 80.6% of the respondents picked the U.S., followed by North Korea (9.7%), Japan (5.1%), China (3.9%), and Russia (0.5%). An overwhelming percentage—80%—of South Koreans feel the U.S. is the closest country while less than 4% of them chose China. This shows, even in case of South Korea’s nuclearization, its people will still want to maintain the ROK-U.S. alliance and preference for China will never prevail.
North Korean nuclear and missile threats to South Korea and the U.S. continue to rise to a very serious level. Faced by such a situation, the ROK and the U.S. should be prepared for a worst-case scenario of “a nuclear war with the DPRK.” If non-nuclear South Korea gets attacked by North Korean tactical nuclear weapons, and the U.S. hesitates to use or chooses not to use its nukes against North Korea out of the fear for nuclear retaliation, South Korean people’s confidence in the ROK-U.S. alliance will suddenly be destroyed.


On the contrary, if South Korea is armed with its own nuclear weapons, it can respond to the North’s nuclear attack with its own nuclear arsenal, and the U.S. will not have to worry about whether to use nuclear weapons to defend South Korea. In this way, the ROK-U.S. alliance can avoid being put to the test, and the U.S. can avoid the worst-case situation of a nuclear war with North Korea. As a result, Seoul’s nuclearization will contribute to protecting the U.S. homeland and the citizens’ lives from Pyongyang’s nuclear threat and to consolidating the ROK-U.S. alliance as a permanently enduring one.
If South Korea possess its own nuclear weapons, North Korea will care more about South Korean nukes than distant American ones, hence rendering the U.S. more secure. Furthermore, it will raise the threshold of using nuclear weapons for North Korea since the country will have to be more prudent in using them. Pyongyang will no longer be able to ignore the South Korean military like it did before and have no choice but to participate in the inter-Korean arms control talks to prevent accidental use of nuclear weapons. Therefore, South Korea’s indigenous nuclearization is certainly the “best option” rather than a “worst possible option” for the U.S. and the alliance.
Some experts claim that the ROK-U.S. alliance will become useless and be dissolved if South Korea successfully develops its own nuclear weapons. However, it is clearly not true. Since South Korea is surrounded by superpowers such as China, Russia, and Japan, if the alliance is dissolved, the ROK will be in a very complicated situation in which it has to newly establish its security strategies towards these superpowers in addition to the DPRK. Hence, it is the South Korean government’s vital interest to maintain the ROK-U.S. alliance—under the condition that South Korea cannot move to another part of the globe. In conclusion, nuclear-armed South Korea, rather than a non-nuclear South Korea, will become a more reliable and stronger ally in the Northeast region to the U.S.
Ⅵ. Conclusion


The South Korean nuclearization will deter North Korea’s nuclear threats, encourage China to engage itself more actively in resolving North Korea-related issues. Therefore, it is very irrational for South Korea-U.S. alliance not to seriously consider the idea. Even though Seoul pursues nuclear weapons development in the future, its objective will never be to become a nuclear superpower. It will pursue only nuclear weapons sufficient to secure a reliable deterrence against the North’s nuclear weapons. Moreover, if South Korea builds up its own nuclear arsenal, the country will be able to manage its nuclear weapons stably like the Great Britain and France, and providing high level of transparency to its ally U.S.
In the past, the U.S. imposed sanctions against India when the latter announced that it had conducted five underground nuclear tests in 1998. However, the sanctions did not last long. Even former U.S. President George Bush visited India in March 2005 to make the U.S.-India Civil Nuclear Agreement. At that time, the U.S. accepted the India’s nuclear development to check China, making an exception to the principle of non-proliferation. Nicholas Burns, then Under Secretary of State for Political affairs justified such an action, which cripples the NPT regime, saying that India received special treatment from the US since it had democratic faith, unlike North Korea and Iran, and made a firm commitment to allow international inspections. South Korea can be considered to be more democratic than India, which still maintains the caste system, and certainly will accept the same level of international inspections that India promised to receive.
As the U.S.-Russia bilateral relations has extremely exacerbated since the Russian invasion of Ukraine in 2022, no additional sanctions against North Korea could have been adopted at the UNSC even when North Korea test launched ICBMs. It is also very unlikely that sanctions against North Korea will be adopted even in case of North Korea’s seventh nuclear test. As such, a serious crack occurred in the cooperation system for non-proliferation among the nuclear weapons states after the outbreak of Russia-Ukraine War. In this situation in which Russia and China vetoed to adopt a UNSC resolution to impose an additional round of sanctions against North Korea in response to its ICBM test-launch, it is unimaginable that the U.S. will push for adoption of sanctions by the UNSC or push forward with its own sanctions against South Korea in case it pursues nuclearization to overcome anxiety over North Korean nuclear threat.
Source: Wikipedia
Desiderio is one of the busiest US Army airfields in the world. Source: US Army.
The U.S. has its largest overseas military base in Pyeongtaek, which is very close to China. For this reason, the strategic value that South Korea has to the U.S. is also growing as the U.S.-China strategic competition intensifies. Furthermore, Washington puts emphasis on the cooperation with Seoul, Taipei, and Tokyo in the semiconductor industry. Taking these factors into account, it is not realistic to claim that South Korean economy will collapse due to harsh sanctions imposed by the U.S. in case of its own nuclearization.
Such claims also undermine the spirit of the ROK-U.S. alliance. The principal reason for South Korea to push ahead with the indigenous nuclearization is the fear for North Korean nuclear. Therefore, it is not reasonable if the U.S. destroys the South Korean economy to oppose its nuclear armament, and that will further hurt the world economy, which has already been faltering since the Russian invasion of Ukraine. The country that would most welcome such a situation would be the DPRK. This is why I see no possibility for the U.S. to make such an irrational worst choice which goes against the national interests of itself and the West.
In 1945, South Korea was one of the most impoverished countries when it obtained independence from the Japanese imperial rule. Not only has the Korean economy experienced a rapid economic growth, becoming the 10th world’s greatest economy, but also proved high resilience, showing quick recovery from the Asian financial crisis in 1998 through a concerted effort such as the “gold-collecting campaign.” The South Korean economy proved its resilience again in 2016, when China imposed a massive economic retaliation against the ROK in response to the latter’s deployment of a missile defense system called Terminal High Altitude Area Defense (THAAD). Even amidst the COVID-19 pandemic crisis, the ROK experienced a relatively minor damage to human life and its economy compared to other countries thanks to the citizens’ active cooperation. The Korean people have demonstrated strong unity in the face of crisis. It would be thus a very serious misjudgment if some experts in the U.S. thought that sanctions would break the will of the Korean people.
North Korean nuclear weapons exist close to South Korea’s Military Demarcation Line while the U.S. nuclear weapons are distant. While all the three countries—the DPRK, PRC, and Russia—on the other side possess nuclear weapons, only the U.S. is a nuclear weapons state among the U.S., the ROK and Japan.
Source: Federation of American Scientists
In addition, China’s nuclear stockpile is expected to quadruple, reaching 1,500 warheads by 2035.[7] This number still falls short of the U.S.’ or Russia’s nuclear stockpile, however, if this trend continues, the playing field in Northeast Asia is projected to tilt in favor of North Korea-China-Russia rather than South Korea-the U.S.-Japan as time passes.
Under such circumstances, South Korean possession of nuclear weapons would effectively check North Korean ones, and if Japan arms with its own nuclear weapons, it will be of great help to the U.S. in containing Chinese nukes. The Japanese case is different from the Korean one since anti-nuclear sentiment is strongly present among the Japanese citizens. Hence, it will be more difficult for Japan to push ahead with the indigenous nuclearization even in case of South Korea’s nuclear armament. However, if Chinese military expansion continues, the Japanese public will eventually realize the necessity of having their own nuclear weapons.
Recently, Pyongyang has successfully test fired the new “monster” missile believed to be the world’s largest road-mobile ICBM. However, the UNSC failed to adopt any additional sanctions in response to that. Against this backdrop, the U.S. security strategists will have to seriously consider their options—either sticking to the faltering NPT system and just watching the advancement of North Korean and Chinese nuclear capabilities; or accepting the nuclearization of South Korea, or South Korea and Japan, to check more effectively the nuclear weapons in Pyongyang and Beijing.
Some American experts have warned that Seoul will face sanctions such as withdrawal from the NPT and Nuclear Suppliers Group (NSG) if it pursues its own nuclear weapons development. However, it is difficult to understand that the U.S., which tolerated the possession of nuclear weapons by India and Pakistan for its national interest, cannot accept South Korea’s nuclear weapons possession, which is in the national interest of both South Korea and the U.S. in the long run.
Furthermore, even after the U.S. accepts the nuclear weapons of India and Pakistan, the number of “de facto nuclear states” has not particularly increased. This means that even the nuclearization of South Korea, which is faced by North Korea’s serious nuclear threat, is not expected to contribute to proliferation. Currently, China and Russia are virtually tolerating North Korea’s nuclear weapons and even insisting on relieving international sanctions on North Korea.
In this context, if the U.S. takes an attitude of intolerance towards South Korea’s nuclear weapons development, it will be only to benefit the other side of the confrontation—a confrontation of the DPRK-PRC-Russia versus the ROK-U.S.-Japan—in the Northeast Asia region. Therefore, the American experts should not threaten that the South Korean economy will be hit hard by the U.S. and international sanctions if it pursues its own nuclear weapons. Rather, they should argue that Washington must accept Seoul’s nuclearization if China and Russia continue to tolerate North Korea’s nuclear weapons. This way, when the U.S. understands and actively defends South Korea’s position, the Korean public’s confidence in the U.S. and the ROK-U.S. alliance will be further solidified.
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Read the other articles in the series:
Part I: The Failure of Denuclearizing North Korea
Notes
[6] “‘Seoul has to adjust to a North with nuclear arms’.” (Interview with John Mearsheimer.) Korea JoongAng Daily, 2013 Feb. 22. https://koreajoongangdaily.joins.com/2013/02/22/politics/Seoul-has-to-adjust-to-a-North-with-nuclear-arms/2967578.html
[7] https://www.donga.com/news/article/all/20221201/116782237/1