US-ROK Alliance


North Korea’s Olympic outreach brought an easing of tensions between North and South Korea after a year of escalating tensions throughout 2017. After delivering a somewhat conciliatory New Year’s address, Kim Jong-un sent a substantial delegation to the Winter Olympics in Pyeongchang, led by the North’s titular head, Kim Yong-nam, accompanied by Kim Yo-jung, Kim Jong-un’s younger sister, and a cheerleading squad—an “army of beauties.” The North’s charm offensive was wildly successful. The “princess of Pyongyang,” in particular, has done much to put a human face on the totalitarian regime.  While President Trump had been taking a tough line against North Korea, even threatening it with annihilation if it continues advancing its nuclear and missile programs, he has now contributed to a slight thaw in inter-Korean relations by agreeing to postpone the annual US-ROK military exercises until after the Paralympics in mid-March.  Furthermore, in a recent interview with The Washington Post, Vice President Pence signaled Washington’s possible new openness to diplomacy when he implied that it is now willing to sit down and talk with the Kim Jong-un regime while the sanctions campaign is ongoing.1

Anyone who recognizes how disastrous another Korean War would be—it could result in the deaths of millions of people and the destruction of Seoul—will welcome this easing of tensions. President Moon is right to try to open lines of communication with Pyongyang and invite North Koreans to participate in the Winter Olympics. After all, even at the height of the Cold War, Washington and Moscow talked to one another and even agreed to set up a hotline between the capitals so as to avoid an accidental nuclear war—an example that Seoul and Pyongyang, as well as Washington and Pyongyang, would be well advised to emulate today.

But South Korea, while rightly seeking to avoid a conflict, should continue to be clear-eyed about what the next steps in engagement with North Korea will entail—and avoid a potentially disastrous rift with Washington by adopting an overly accommodating policy to Pyongyang. The US alliance remains the cornerstone of South Korean security and Moon would be well advised not to risk it by going too far to accommodate North Korea—an effort that is, in any case, likely to fail.

Kim Yo-jung brought to Seoul a rare invitation from Kim Jong-un for Moon Jae-in to visit the North for a summit meeting. If this summit takes place, it would be the first between the leaders of the two Koreas in 11 years. But as Moon himself knows too well, the Kim family regime is not in the habit of giving something for nothing. Typically, in the past, it has always demanded lucrative concessions in return for its willingness to talk.  Summit prices on the two previous occasions, in 2000 and 2007, had been particularly costly for Seoul and lucrative for the North. In many ways, North Korea has been engaged in a protection racket—carrying out attacks on South Korea and then demanding subsidies to stop. During the years of the “Sunshine Policy” under Kim Dae-jung and Roh Moo-hyun, over $8 billion in economic subsidies and assistance flowed from South to North Korea.2 For the South-North summit meeting in 2000, Kim Dae-jung hand-delivered to Kim Jong-il a suitcase filled with $500 million in cash.3 Yet none of these engagements and subsidies dissuaded North Korea from accelerating its nuclear and missile programs or from its shameful human rights abuses against its own population. 

Today, North Korea is likely feeling the sting of sanctions, which have been tightened even further under the Trump administration with the support of the United Nations Security Council. Each round of North Korea missile and nuclear tests has been met by an increasingly tough sanctions resolution from the. Security Council. Even China has not only signed onto tougher Security Council sanctions since last year, but it began to enforce them to a greater degree than many Korea watchers had expected. Between 2016 and 2017, North Korea’s exports to China declined 37%, and if the sanctions are fully implemented (granted, a big if), the decline could be over 90% this year.4 No doubt Kim Jong-un sees his Olympic outreach as the first step of an attempt to win a relaxation of sanctions. The North is determined to break apart the international sanctions campaign and, rightly or wrongly, it sees Seoul as the weakest link in the “maximum pressure” chain.5

In addition, the North is also watching every move and word coming out of Washington closely and is likely spooked by the talk of a “bloody nose” option—meaning a limited military strike to dissuade the North from pursuing its nuclear and missile designs before it fields a nuclear-tipped ICBM capable of hitting the United States. Although recently the Trump administration appears to be downplaying the idea that it is considering a military strike to prevent Pyongyang from crossing the ICBM threshold, it is hard to ignore the consistent signals that senior officials had been sending over the past several months. National Security Adviser H.R. McMaster and others have been talking about a “preventative war,” saying we are “running out of time” to solve the North Korean problem, arguing that deterrence cannot work, and warning that North Korea has brought the world “closer to war.”6 North Koreans have recently told a visiting foreign delegation that they saw the withdrawal of Victor Cha’s nomination to be ambassador to South Korea as a hawkish stance by the United States.7 From the North’s perspective, the détente with Seoul buys Pyongyang much needed time and reduces the chances of possible kinetic action against the North—the United States is less likely to bomb the North if it is engaged in talks with Seoul—while driving a wedge into the US-South Korea alliance.

ROK-US Coordination

Moon Jae-in has shown himself clear-eyed about the North Korean threat thus far by maintaining the deployment of the US THAAD missile-defense system, which many progressives have criticized, and going along with the United States in pursuing a maximum-pressure policy against the Kim regime, including maintaining strong sanctions on North Korea. While the Moon administration would like to take advantage of the momentum coming out of the Olympics to see if a further breakthrough is possible with the North, Moon must avoid the trap that Kim Jong-un is setting for him, trying to take advantage of his hopes for peace to snooker South Korea into making unilateral concessions to the North.  Such a move would unfairly reward the most repressive regime in the world for its dangerous, destabilizing actions, particularly its nuclear and missile tests, which threaten to ignite another conflict on the peninsula.

More than that, if South Korea were to make concessions now to North Korea, without the North having done more to earn them, it would place itself in an impossible position with Washington.  Trump came into office hinting that he might scrap the US-South Korea Free Trade Agreement (KORUS FTA) and even pull US troops out of South Korea if Seoul did not pay more for their upkeep. He has not so far made good on those threats, but, as he is well known for his unpredictability, it cannot be ruled out that he could very well do so if he thought that South Korea was undermining his get-tough approach with North Korea.  Despite his moving speech to the National Assembly, Trump has consistently shown that his priority is concern for his own country—hence his slogan “America First.” Above all, he wants to stop North Korea from threatening Washington with nuclear destruction, and it is possible that he could take actions that would jeopardize America’s 73-year-old alliance with South Korea if he deemed it expedient to do so.

The Moon administration also faces domestic constraints that should make it difficult to make significant concessions to the North to keep the dialogue going. While the South Korean public broadly supports engagement with the North, conservatives and the younger generation of South Koreans are extremely skeptical about the North’s intentions.8 Indeed Moon appeared to have reassured Pence that South Korea will not ease up on the sanctions or pressure until the North gets serious about dismantling its nuclear program. As a result, Pence was also able to concede to Moon that, as long as “maximum pressure” was sustained, the United States would support an inter-Korea summit. He even expressed willingness for American representatives to sit down with the North Koreans.

North Korea’s long-held goal has been to break up the US-ROK alliance. It is imperative that Washington and Seoul continue to stay on the same page regarding the next steps of dealing with the North Korean threat. Thus far, the Trump and Moon administrations have been successful in strengthening the coalition of UN member states to enforce a successful sanctions campaign against the North. Washington and Seoul, recognizing that sanctions require time to work, need to continue to maintain unity in moving forward with this effort.   

What is more, if South Korea were seen to be out of step with Washington, Trump would be more likely to act unilaterally. He might even launch a preventative strike against North Korea that could trigger a general conflagration on the peninsula. Moon can help in restraining the United States from precipitous action if he follows America’s tough line on sanctions against North Korea, while he reaches out to the North to see if any diplomatic breakthrough is remotely possible. Sanctions are just beginning to bite, and as the case of Iran showed, it may be years before Pyongyang feels enough pressure to seriously consider negotiating a verifiable freeze or even dismantlement of its nuclear program. In the meantime, by all means Seoul and Washington should establish lines of dialogue with Pyongyang and Moon could even meet with Kim Jong-un to see what may be possible in the future—but without making any preemptive concessions that North Korea has not earned. Even if a breakthrough is not forthcoming, talks can be useful in assessing the North’s intentions and preventing an accidental conflagration.

Transfer of OPCON

While engaging in a limited way with the North, Seoul should think carefully about the timing of the transfer of wartime military operational control (OPCON) from the current Combined Forces Command (CFC), which is led by a four-star US general with a South Korean four-star deputy commander, to a new joint command led by a South Korean commander. The Moon government expressed its interest in completing the OPCON transfer before its term is over, but the allies should be concerned about the optics of OPCON transfer at a time when tension with the North is growing. What message does it send to North Korea to accelerate the transfer in the aftermath of the North’s sixth nuclear test—when the weapon tested was said to be a hydrogen bomb—three ICBM tests, and the North’s increasing asymmetric capabilities, including its chemical and biological weapons stockpile, as well as its proliferation activities? The allies need to work together to make sure that when and if OPCON transfer takes place, Pyongyang does not interpret it as a weakening of the alliance’s deterrence. 

Uncertainties in the Alliance

Washington and Seoul’s 73-year old alliance is strong and enduring. The alliance was particularly robust between 2009 and the end of 2016, cemented by Washington’s strong relationships with two successive conservative governments in Seoul. But there is no denying that today there are more uncertainties in the alliance, attributable to changes in the leadership in Seoul and, more importantly, in Washington. Despite efforts by both capitals to portray the bilateral relationship to be stronger than ever, the Moon administration is likely unnerved by the Trump administration and recognizes that the two allies are, perhaps, at the most fraught moment in the history of this bilateral relationship. Trump’s incendiary and intemperate rhetoric has not helped in alliance management. Ever since he was a presidential candidate, he has issued repeated threats to leave the KORUS FTA, which the countries are now renegotiating at his insistence. Trump also demanded at one point that South Korea should pay for THAAD, while constantly griping that Seoul needs to increase its share of the cost to subsidize the US troop presence stationed in South Korea.

In this context, there are several important issues of concern in the alliance other than coordinating a North Korea policy. One important source of contention between the two allies is differing perception of South Korea’s regional relationship with its neighbors and over Seoul’s reluctance to accede to a deeper US-South Korea-Japan trilateral security relationship. The Trump administration is troubled by what it perceives as an understanding, if not an agreement, between Seoul and Beijing on the “three noes”—South Korea’s pledge of no additional THAAD deployment, no participation in the US-led regional missile defense network, and no collaboration or establishment of a trilateral military alliance with the United States and Japan.9  

The “deal” or unwritten concessions was announced on October 31, 2017, just days before Trump’s Asia tour kicked off. Reportedly, in the three months of negotiations between the Blue House and China’s Foreign Affairs Ministry that produced the deal, the two sides agreed to have South Korean foreign minister Kang explain these three “noes,” rather than commit them to paper. In fact, Kang told the national parliament that the Moon government was not seeking any of the three possible paths—additional THAAD deployment, participation in US-led regional missile defense and a closer security relationship with Japan—that the Chinese are concerned about. This was followed by Moon’s statement that Seoul would pursue “balanced diplomacy” with both Washington and Beijing.

Predictably, the three noes were not well-received in Washington. Even as the Blue House tried to alleviate the Trump administration’s concerns by saying that this was not a formal agreement between Seoul and Beijing, it was nonetheless seen as Seoul conceding to Beijing a voice in its future security options. Since one THAAD unit is already deployed in South Korea, the Moon administration could have reasoned that there would be little reason to deploy another and therefore could give such a “promise” to Beijing. But from Washington’s perspective, as the North’s nuclear and missile threat intensifies, further deployment of THAAD may be necessary and thus the Trump administration was frustrated with this understanding or agreement between Moon and Xi Jinping.

The Trump administration was also perturbed by the Blue House’s supposed promise to Beijing that Seoul will not be part of the US missile defense network and that there will be virtually no possibility of a trilateral military alliance forming between South Korea, the United States, and Japan. From Washington’s perspective, strengthening trilateral defense cooperation between Washington, Seoul, and Japan makes sense particularly in deterring the North Korean threat. The traditional alliance network in the Northeast Asian region consists of a “hub and spokes” of bilateral treaties between the United States and its allies South Korea and Japan. But Washington hopes to move these bilateral alliances in the direction of collective security to deal with the North Korean threat more effectively. Both Seoul and Tokyo are on the front lines, directly exposed by North Korea’s nuclear weapons and missiles, not to mention cyber, biological, chemical and other threats.

There are also hopes in Washington of knitting together various countries throughout Asia that are aligned with the United States—including not only Japan and South Korea but also India, Australia, New Zealand, Singapore, the Philippines, Vietnam, Malaysia, Taiwan, and Indonesia—into a broader security architecture to contain the growth of Chinese power. Naturally, this is the last thing Beijing would like to see, and it will apply all the leverage it possibly can on South Korea and other nations to avoid joining such an American-led coalition.

From South Korea’s perspective, one way to counter the talk of a “bloody nose” strike against the North coming out of Washington is to respond to the Trump administration’s concerns by presenting an alternate plan that would be appealing to the administration. A good substitute option that makes sense is increased deterrence and gradual rollback of the North Korean threat, including, yes, a trilateral defense alliance between Seoul, Tokyo, and Washington—in spite of Beijing’s objections. But Seoul’s historically fraught and still bitter relations with Tokyo hamper this effort. The South Korea-Japan relationship remains among the most troubled relationships between mature liberal democracies because of lingering tensions over historical issues such as the mistreatment of “comfort women” (sex slaves) and competing territorial claims over two tiny rocky islets, known as Dokdo to Koreans and Takeshima to the Japanese, in the East Sea (as it is known to Koreans) or Sea of Japan (as it known to the Japanese).

The South Korean government is likely concerned about Beijing’s potential wrath if Seoul were to take steps to pursue trilateral military alliance with the United States and Tokyo. Beijing, after all, adopted year-long retaliatory measures in response to South Korea’s decision to install the THAAD system. What resulted were sanctions against hundreds of South Korean firms working in China. Sales of South Korean automobiles in China reportedly dropped roughly 44% as a result. Beijing also banned package tours to South Korea, leading to a 50% drop in Chinese visitors through the first 10 months of 2017 and more than $5 billion in economic losses for South Korea.10

Despite Seoul’s weariness to strengthen defense cooperation with Tokyo and Washington, it would be this very movement towards a regional collective security arrangement that would put real pressure on Beijing to rethink its North Korea strategy.  Despite doing more on the sanctions front, China still has not fundamentally shifted from its strategy of sustaining the Kim dynasty in the hope of ensuring a friendly nation on its northern border that would provide a buffer between China and the democratic, pro-American South Korea. But if the United States were to strengthen missile defense and cooperation with its two key allies in the region, Seoul and Tokyo, it would put additional pressure on Beijing to think twice about its policy of supporting North Korea.

While taking this step is not an easy one for Seoul, the Moon administration should think carefully through the pros and cons of pursuing trilateral defense with Washington and Tokyo. By taking legitimate steps to strengthen mutual defense with Washington and Tokyo, it would have an opportunity to shift China’s strategic calculations vis-à-vis Pyongyang while lessening the probability of Washington ultimately resorting to kinetic action against North Korea. If taking steps toward trilateral defense cooperation is too big of a move for South Korea right now, Seoul should at least think about at least agreeing to a collective security statement with Washington and Tokyo that an attack by North Korea against any one of the capitals would constitute an attack on all. This is not such a far-fetched scenario as some in Seoul might imagine. In fact, the three capitals came close to issuing such a collective statement in December 2010.11

The US-ROK Alliance Can Emerge Stronger than Ever

With North Korea on the brink of possessing a nuclear ICBM capability, the US-South Korea alliance is in the spotlight. Since its inception in 1953, the alliance has been the key mechanism facilitating security cooperation between Seoul and Washington. The alliance has experienced a number of challenges, but the current leadership combination of Trump and Moon has presented a new and fundamental challenge to the long-standing alliance. Most critically, the two hold fundamentally different perspectives on how to ultimately resolve the North Korean crisis. But as much as the escalating North Korean crisis has highlighted strain in the alliance, it also presents an opportunity. If Seoul and Washington could cooperate and work together to disrupt North Korea’s nuclear program through non-kinetic means, the alliance would emerge stronger than it has ever been. 

What this means for Washington is that it must take steps to ensure that it consults closely with the Blue House on all aspects of its North Korea strategy and policy. Moon Jae-in has publicly insisted that Seoul has an “absolute right to veto” a decision by Washington to attack North Korea, be it a limited attack or more.12 He has reason to be saying so. Trump administration officials have stressed repeatedly that all options are on the table regarding North Korea while stating that there is no possibility of accepting a nuclear-armed North Korea relying on traditional deterrence.13 Yet, there is no indication whatsoever that Washington believes that Seoul could veto a decision if Washington decided to launch military strikes in the North to eliminate Kim’s nuclear and missile threats to America’s security.

Such a unilateral move by Washington would be a catastrophic mistake. Any unilateral action on behalf of Washington such as a “bloody nose” strike against North Korea would spell the end of the US-South Korea alliance. Indeed, Moon’s uncharacteristically candid rejection of the Trump administration’s threats of a kinetic strike against North Korea and his promise to prevent conflict at all costs reflect not only tension in the alliance but the reality that Seoul would likely bear the brunt of the North’s retaliation if Washington were to preventively strike North Korea. If a kinetic strike against the North resulted in a North Korean conventional, chemical, or nuclear attack on South Korea, public outrage at the United States would be overwhelming and possibly fatal to the alliance.

Finally, the United States should increase the credibility of its extended nuclear deterrence and assurance. Some South Korean strategists are arguing for a return of US tactical nuclear weapons to the Korean Peninsula, but this is for now not necessary. The Obama administration made commitments that US tactical weapons would be deployable in Asia. If necessary and wanted by Seoul, the Trump administration could follow up on them by refurbishing nuclear weapons storage areas in Asia and more regularly exercising nuclear-capable fighter aircraft in the region. Washington could also re-introduce more flexible tactical nuclear options, such as the TLAM-N submarine-launched nuclear cruise missile. Some critics might fear that these steps could increase the risks of escalation with the North, but, in fact, they could provide clear evidence of US capability and intent to extend deterrence to Asia and reduce the chances of miscalculation by the North.14 

Washington’s commitment to extended nuclear deterrence also averts a potentially destabilizing regional arms race in the Northeast Asian region à la Pakistan and India.The security arrangement the United States has had with South Korea since 1953, which includes a nuclear guarantee by which the United States pledges its readiness to protect the South, has enabled the South to disavow the development and deployment of nuclear weapons.


The deep institutionalization of the alliance means that it is fundamentally well positioned to weather the challenges ahead. But that does not mean that Trump and Moon can rest on their laurels. Both leaders must look past political differences if they are to ensure that the alliance remains an effective means of bringing balance to an increasingly unstable Northeast Asian security environment, because there is no viable alternative to close cooperation.

In figuring out the way ahead, Trump and Moon need to be respectful of each other and aware of the differing imperatives they each face. Moon needs to avoid adopting an overly dovish stance toward North Korea that could alienate Trump and hence disrupt the US-ROK alliance that remains the cornerstone of South Korean security. Trump needs to avoid taking an overly hawkish stance towards North Korea that could trigger a conflict with catastrophic consequences for America’s allies in South Korea. He must also avoid alienating South Korea by scrapping the KORUS FTA just when it is imperative that Seoul and Washington be on the same page.
There is plenty of room for the leaders of South Korea and the United States to forge a mutually acceptable path forward that consists of stronger sanctions on North Korea—the “maximum pressure” policy—combined with talks assuming that Kim Jong-un continues to show interest in such a dialogue. The talks are unlikely to yield results for the time being, but they could at the very least be helpful in understanding Kim’s motivations and avoiding a potentially disastrous miscommunication or miscalculation. Down the road, after the sanctions have begun to truly bite, Kim may finally be in a more accommodating mood—in which case talks could result in a binding agreement like the Iranian nuclear deal (the Joint Comprehensive Plan of Action) that would begin to reduce the North Korean WMD threat through either a verifiable freeze or even dismantlement. But only when Kim feels that he has more to lose than to gain from going full speed ahead with his WMD program will he be open to meaningful negotiations. And that will not occur anytime soon. Overtures for talks in the meantime have to be seen for what they are—the latest North Korean ploy to lessen the pressure on the regime. As long as Trump and Moon maintain close contacts and work in harmony, they can ensure that the US-South Korea alliance emerges stronger than ever from the current crisis.

1. Josh Rogin, “Pence: the United States is ready talk with North Korea,” The Washington Post, February 11, 2018,

2. Larry A. Niksch, “Korea: U.S.-Korean Relations — Issues for Congress,” Congressional Research Service, Updated January 5, 2018, 12-13,

3. Ibid, 12.

4. Kim Byung-yeon, “Strong sanctions against North Korea lead to denuclearization negotiations: Data-analyzing North Korea,” Joongang Ilbo, January 22, 2018.

5. For more on this argument, see Nicholas Eberstadt, “The Pyeongchang Olympics is North Korea’s winter offensive,” The National Interest, February 15, 2018,

6. Jason Le Miere, “U.S. prepared to launch ‘preventive war’ against North Korea, says H.R. McMaster,” Newsweek, August 5, 2017,

7. Readout from a foreign delegation’s visit to North Korea at the Center for Strategic and International Studies, February 12, 2018.

8. Chico Harlan and Yoonjung Seo, “Younger South Koreans are deeply skeptical of North Korea’s diplomatic offensive,” The Washington Post, February 12, 2018,

9. South Korean Foreign Minister rules out additional THAAD deployments, joining US MD system,” Hankyoreh, October 31, 2017,

10. Mauldin Economics, “China Unofficially Ends the Dispute with South Korea Over THAAD,” Valuewalk, February 17, 2018.

11. Michael J. Green and Matthew Kroenig, “A New Strategy for Deterrence and Rollback with North Korea,” War on the Rocks, October 19, 2017,

12. Hoo-yeon Kim, David Tweed, Narae Kim, “Moon vents Korea frustration by asserting right to veto U.S.,” Bloomberg Politics, August 15, 2017,

13. Jim Garamone, “Mattis: U.S. will not accept nuclear-armed North Korea,” U.S. Department of Defense, October 28, 2017,

14. Michael J. Green and Matthew Kroenig, “A New Strategy for Deterrence and Rollback with North Korea.”

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