After a decade of conservative rule culminating in the March 2017 impeachment of President Park Geun-hye, South Koreans unsurprisingly voted for change, electing Moon Jae-in of the left-leaning Democratic Party to the presidency in May. Moon campaigned on a largely domestic platform, but critics have suggested that his election could lead to a chill in U.S.–South Korean relations. What does his arrival in the Blue House portend for Seoul’s approach to North Korea and regional geopolitics over the next five years?


At the most basic level, Moon’s election restores a needed legitimacy to the South Korean government, both at home and abroad, that had been lost during the Park administration’s long collapse. This legitimacy is especially important today given the heightened tensions on the Korean Peninsula: U.S. President Donald Trump has made dealing with North Korea’s nuclear missile program a priority, and Pyongyang has resumed testing its ballistic missiles after a six-month pause. Since mid-February, North Korea has launched a dozen short-, medium-, and intermediate-range missiles, including three in Moon’s first three weeks as president. More will surely follow.

Moon said during the campaign that he wanted to regain the initiative on the North Korean issue. This is a position that resonates among South Koreans, who feel bypassed on the international issue of greatest importance to them because outside powers appear to dictate the pace of events on the peninsula. Moon also signaled his desire to pursue inter-Korean engagement, which he framed in terms of “conditional dialogue.” Such engagement would not necessarily mean a return to the “Sunshine Policy” of his ideological mentor, Roh Moo-hyun, which attempted to moderate Pyongyang’s behavior through economic incentives and enhance inter-Korean exchange. The policy’s lack of conditionality and failure to produce a lasting de-escalation discredited it in the eyes of many. But Moon’s tough statements following North Korea’s recent missile tests—he called for additional sanctions in May—have helped to dispel charges that he is soft on Pyongyang.

Moon’s election restores a needed legitimacy to the South Korean government, both at home and abroad.

Moon is unlikely to pursue any radical changes in part because his highest priority is his domestic agenda. The recent election was fought primarily on economic issues, not on security or foreign policy. Moon’s domestic agenda, which includes reform of the country’s chaebol (conglomerates) and a heavy dose of government spending on job creation and welfare measures, will absorb much of his political capital. And despite an emphatic victory in the presidential election, Moon’s party controls barely one-third of the 300-seat National Assembly, meaning that he will need bipartisan support to pass legislation and win confirmation for cabinet-level appointments. The fact that Moon has not completed his cabinet lineup more than a month after assuming office reveals the depth of this dependence. 

With Moon’s party occupying such a marginal position in the legislature, public opinion will act as a constraint on external policy. Moon is currently shining in the polls, but the majority of South Koreans are wary of unconditional engagement with the North, having witnessed years of provocations from Pyongyang that have claimed both military and civilian lives. Moon’s conservative rivals will no doubt use national security as a line of attack if he projects weakness or expresses allegedly pro–North Korea sentiments.

Moon supporters hold up their cell phone lights at a campaign rally in Seoul, May 2017.
Kim Kyung-hoon / Reuters

If Seoul is unlikely to radically shift its North Korea policy, Pyongyang is unlikely to be swayed by economic inducements from South Korea, such as the reopening of the Kaesong Industrial Complex, as Moon mooted before the election. The North’s economy is strengthening, and Supreme Leader Kim Jong Un has set his sights on developing an intercontinental ballistic missile, which he believes will guarantee his regime’s survival. At this point, convincing Pyongyang to voluntarily denuclearize is probably impossible, although that won’t stop Moon from trying. 


One foreign policy issue where Moon faces better prospects for success is in resetting Chinese–South Korean relations, which deteriorated during the second half of Park’s presidency—dramatically so following Seoul’s decision, last July, to allow the United States to deploy its Terminal High Altitude Area Defense (THAAD) antimissile system on South Korean territory. China, which adamantly opposed THAAD for allegedly undermining its own security, has since responded with a coercive campaign of informal economic sanctions targeting South Korean interests, including reduced tourist inflows and shutting down department stores owned by Lotte, the company that owns the land on which the THAAD battery is stationed. 

Moon studiously avoided taking a position on THAAD during the campaign, despite his unease about the rushed nature of the deployment and his party’s desire to placate China. It is unusual for a defense system to become so politicized in South Korea, but the strength of China’s reaction polarized the issue, pitting conservatives who value South Korea’s alliance with the United States against progressives who are opposed to expanding defense cooperation with Washington. Moon also reacted calmly to Trump’s provocative intervention, late in the campaign, suggesting that South Korea should pay $1 billion toward the cost of THAAD, which the United States had previously promised to cover. (Trump’s outburst was widely seen as helping Moon.)

Moon faces a dilemma on THAAD—there is no obvious compromise that would please both Washington and Beijing—but he has so far kept his options open. He probably prefers to reverse the deployment, given its limited defensive value and the importance he has attached to a clean slate with China. In addition, his advisers are distrustful of how U.S. and South Korean defense authorities accelerated THAAD’s rollout during the postimpeachment vacuum. Some of his advisers see it as a Trojan horse, enmeshing South Korea and Japan within a U.S.-led missile defense network intended not to defend against North Korea but to counter China. Since he has taken office, Moon’s suspicions have been heightened by the revelation that his Defense Ministry had approved the shipment of four additional THAAD launchers to South Korea without notifying the Blue House. This has only strengthened Moon’s conviction that there needs to be more civilian control over the military.  

China, for its part, continues to strongly oppose THAAD. But although informal sanctions remain in place, Beijing has sent uniformly positive signals toward Moon. Chinese President Xi Jinping even took the unprecedented step of making a 46-minute phone call to congratulate Moon on his victory and invite South Korea to attend the recent Belt and Road Summit in Beijing. Moon told Xi that he would send a delegation to Beijing as soon as possible to resolve the row over THAAD.

More significant than THAAD, however, is the transfer of operational command (OPCON) over South Korea’s armed forces from U.S. to Korean authority, which had been postponed under Roh and Park but is bound to bounce back under the new administration.

Under current arrangements, the United States has OPCON over South Korean forces in wartime. This makes military sense but is seen by some South Koreans, particularly those on the left, as undermining their country’s sovereignty. Previous administrations pushed for transferring OPCON within a set time frame, but the effort was indefinitely postponed in 2014. As a candidate, Moon pledged to achieve the transfer before leaving office in 2022. Yet this will make practical sense only once South Korea has strengthened its capabilities in intelligence, surveillance, and command and control. Doing so will require the investment of significant sums of money on top of increases that Moon has already committed to, including military pay increases and the fast-track development of a South Korean–made missile defense system. Defense spending is already expected to rise under Moon. Given the president’s many other big-ticket priorities, however, a marginal increase is unlikely to cover all that he would like it to.

A U.S. and a South Korean marine at a ceremony commemorating the landing at Incheon, September 2015.
Kim Hong-ji / Reuters

Moon’s nominee for defense minister, Song Young-moo, an ex-navy chief, was involved in the original planning for OPCON transfer under the Roh administration. He was also selected for his record of supporting military reform and, if confirmed, is likely to be tasked with bolstering civilian control. Yet his naval background, although an interesting departure from the orthodoxy of appointing ex-army men, falls short of Moon’s campaign pledge to name a civilian to the defense portfolio.


So far, Moon’s other appointments and nominations suggest that his administration will place more emphasis on diplomacy to supplement South Korea’s defense capabilities and its traditional reliance on the United States. Shortly after North Korea launched the first missile of his presidency, Moon designated a group of special envoys to China, Germany and the EU, Japan, Russia, and the United States. The appointment of a special envoy to Europe is new and signals an effort to broaden Seoul’s focus beyond the major powers in its immediate neighborhood. How far Moon can realistically cast his diplomatic horizons beyond the ever-proximate North Korean challenge is debatable.

Other senior appointments have further underlined this diplomatic focus. Chung Eui-yong, South Korea’s former ambassador to the UN, has been appointed as national security adviser, a role typically given to ex-military men and defense specialists. Moon has also placed Moon Chung-in, a Yonsei University professor who was close to Roh, in an external advisory role. Moon Chung-in is likely to counsel a diversification of South Korea’s foreign policy in search of a more “balanced” approach. That could mean additional bandwidth for midlevel powers such as Australia and Indonesia but also likely signals increased outreach to China.

The most pressing question will be how Moon manages relations with the United States. Moon is scheduled to meet with Trump in Washington on June 29–30, providing the former with an important opportunity to influence Washington’s “maximum pressure and engagement” policy toward North Korea, which until now has relied heavily on China to persuade Pyongyang to reverse its nuclear course. The United States, however, has little reason to fear that Moon’s desire to reengage Pyongyang will undermine its denuclearization efforts, as the constraints on Seoul’s policy are simply too strong. The challenge for Moon and Trump, then, will be to establish a working relationship while avoiding a head-on clash on THAAD or trade.

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  • EUAN GRAHAM is Director of the International Security Program at the Lowy Institute for International Policy. 
  • More By Euan Graham