Yoon’s Impeachment and South Korea’s Future

Introduction

As many South Koreans expected, President Yoon Suk Yeol’s impeachment was finalized on April 4, 2025, by the Constitutional Court. The unanimous vote by the eight justices means that South Korea will hold an election on June 3, 2025.¹ The verdict ended with the statement that “the respondent’s unconstitutional and unlawful acts amount to a serious violation of law that cannot be tolerated from the perspective of constitutional protection, as they represent a betrayal of public trust.”²

Over the next two months, South Korea is going to be consumed by an extremely intense primary campaign within the tarnished conservative People Power Party (PPP) but also inside the major opposition Democratic Party (DP) (although current party head Lee Jae-myung is hands down the favorite to become the DP’s presidential nominee) and a brutal presidential contest.³ Whoever emerges victorious as the next president will put an end to six months of a leaderless South Korea since December 2024, but he faces daunting challenges at home and abroad.

Most importantly, the next president must put into place crucial political reforms such as a bipartisan consensus to revise the 1987 constitution that is built around an extremely powerful single five-year presidency. South Korea is overdue for change to its dominant political culture that is marked by political retributions and vendettas, intensifying hatred between contending political camps and their public supporters, and the absence of compromise across the political spectrum. Absent such reforms, the Republic of Korea’s (ROK) socio-economic futures will worsen significantly, driven by the country’s imploding birthrate (although there was a small improvement in the fertility rate in 2024), the world’s fastest-growing super-aging society, exponential rise in social-welfare costs, and much lower tax revenues owing to anemic economic growth.⁴

Why National Security Will Remain a Priority

How the next South Korean president copes with outstanding foreign policy and national security challenges will depend on his worldview, the makeup of his national security team, and the steps that will be taken by key foreign powers, as well as the approaches that are likely to be adopted by South Korea’s critical ally, the United States. Moreover, Chinese and Russian, responses to Trump’s policies will determine the trajectory of great power relations throughout Trump’s second term. But for critical East Asian allies like Japan and South Korea, a United States that no longer stands at the forefront of the broader Western alliance (including NATO), strengthening and deepening its security and economic ties with Washington will matter less than before. Indeed, the “Trump Shokku” or the Trump shock, reminiscent of Japan’s total surprise at Nixon’s rapid rapprochement with the People’s Republic of China in 1971, is going to consume the lion’s share of Tokyo’s foreign policy concerns. Although South Korea also places its alliance with Washington at the apex of its security posture, different ROK administrations have placed vastly different emphases on ties with the United States. Not so Japan. The good news is that Trump understands Japan’s strategic importance to the United States. The bad news is that such views could change overnight.

Like Japan, South Korea must deal head-on with Trump’s tariffs that were announced on April 2, 2025, which Trump heralded as “Liberation Day” for the United States, or freeing itself from an unfair global trading system. Trump’s tariff wars could not have come at a worse time for South Korea given the ongoing political crisis following Yoon’s impeachment and a snap presidential election. Until a new government comes into office in early June, Seoul won’t be able to enter into any meaningful discussions or negotiations with the United States.⁵ Hyundai Motor Group Chairman Chung Eui-sun announced a $21 billion investment program at the White House on March 24, 2025, including a $5.8 billion new steel plant in Louisiana which Trump praised.⁶ Nevertheless, among twenty countries the United States has free trade agreements with, Korea was hit with the highest tariff of 25 percent, and South Korea said it will provide “emergency support measures” to key industries such as automobiles that will be affected significantly by Trump’s tariffs.⁷

Tokyo is also going to focus most of its energy in the short term, responding to Trump’s unprecedented 24 percent tariff on Japanese goods given its implications for Japanese exports and impact on critical supply chains and financial markets.⁸ However, Tokyo is also concerned about security spillovers, including what Trump may ask in return for continuing to maintain the U.S.-Japan security alliance. In early March 2025, Trump stated that “I love Japan. We have a great relationship with Japan, but we have an interesting deal with Japan that we have to protect them, but they don’t have to protect us…and by the way, they make a fortune with us economically.”⁹ Article V of the 1960 security treaty between the United States and Japan states, in part, that “Each Party recognizes that an armed attack against either Party in the territories under the administration of Japan would be dangerous to its own peace and safety and declares that it would act to meet the common danger in accordance with its constitutional provisions and processes.”¹⁰

By comparison, the 1954 ROK-U.S. defense treaty (Article III) stipulates that “Each Party recognizes that an armed attack in the Pacific area on either of the Parties in territories now under their respective administrative control… would be dangerous to its own peace and safety and declares that it would act to meet the common danger in accordance with its constitutional processes.” (Emphasis added).¹¹ Given that the U.S. fought World War II with Japan from 1941-1945 and played a decisive role in promulgating Japan’s so-called peace constitution, it is understandable that a mutual defense clause was limited to territories under Japanese control.

Trump may seek a massive increase in Japan’s annual cost-sharing support that currently accounts for about $9.2 billion based on a December 2021 five-year agreement.¹² He argued during his first term that South Korea’s annual cost-sharing should go up from about $1 billion to about $5 billion. In November 2024, Seoul signed a new Special Measures Agreement with Washington that South Korea will pay $1.19 billion per year until 2030.¹³ In October 2024 just before he was elected, Trump told the Economic Club of Chicago that South Korea was a “money machine” and that it should pay $10 billion annually for receiving protection through the U.S. Forces Korea (USFK) and that if he were in office “they’d [South Korea] be happy to do it.”¹⁴

For Seoul, how far North Korea’s defense and security ties with Russia will deepen over the next several years is going to be a key barometer of South-North relations. If Moscow transfers advanced fighters to North Korea as well as short-range ballistic missiles or SLBMs, Inter-continental ballistic missiles or ICBMs, and military satellite-related technologies, that would be of paramount concern to South Korea’s defense planners.¹⁵ According to Robert Peters of the Heritage Foundation, Russia could potentially transfer technologies from its space program to help improve accuracy and reliability that are critically important for the effective delivery of nuclear warheads.¹⁶ South Korean officials have stated that Russia has transferred air defense missiles to North Korea as part of Pyongyang’s growing military support for Russia’s war against Ukraine. Seoul’s National Security Advisor Shin Won-sik said in an interview in November 2024 that “It is understood that North Korea has been provided with [air defense] related equipment and anti-aircraft missiles to strengthen Pyongyang’s weak air defense system.”¹⁷

Trump has intimated his wish to reengage with North Korea’s leader Kim Jong Un, and just a day after he was inaugurated, Trump said that “Now, he [Kim] is a nuclear power…[and] I think he’ll be happy to see I’m coming back.”¹⁸ What Trump really meant by calling North Korea a nuclear power is unclear, although South Korea has been adamant that “North Korea will never be recognized as a nuclear-armed state” since that would kill any prospects for future denuclearization of North Korea, although Kim has said repeatedly that he will never negotiate away his nuclear weapons.¹⁹

At the same time, it’s important to recall that previous progressive governments in South Korea strongly supported the creation of a so-called “peace regime” on the Korean Peninsula, including the signing of a peace treaty to formally end the Korean War.²⁰ When the armistice agreement was signed in July 1953, the main signatories were the United States (as head of the United Nations Command or UNC), the ROK, and the People’s Republic of China (PRC), and North Korea agreed to the armistice as part of the UNC. If Trump and Kim announce an end-of-war declaration, it could have serious repercussions for USFK and UNC-Rear, comprised of the U.S. Forces Japan (USFJ), that will play a crucial role as a mid-way station for U.S. reinforcements in the event of a major conflict on the Korean Peninsula.

Still, since Kim has said that he will never negotiate his nuclear weapons and that North Korea has “already gone as far as we could through negotiations” with the United States and that he has no interest in denuclearization talks, it remains unclear how successful Trump will be in enticing Kim back to the negotiating table and agreeing to some type of nuclear agreement.²¹ Over the last several years, Kim has reaffirmed that he will “exponentially increase” the DPRK’s nuclear capabilities and in October 2024, Kim said that if South Korea threatened its sovereignty, he “would use without hesitation all the offensive forces it has possessed, including nuclear weapons…[and] if such a situation comes, the permanent existence of Seoul and the Republic of Korea would be impossible.”²²

Notwithstanding Trump’s desire to reengage with Kim, the first Annual Threat Assessment of the U.S. Intelligence Community issued by the Trump administration in March 2025 noted that North Korea was unlikely to stop its nuclear weapons program: 

North Korean leader Kim Jong Un will continue to pursue strategic and conventional military capabilities that target the homeland, threaten U.S. and allied armed forces and citizens, and enable Kim to undermine U.S. power and reshape the regional security environment in his favor…Kim will act aggressively to counter activities he views as undermining the regime and threaten to use force when he perceives U.S. and allied actions as challenging North Korea’s sovereignty, undermining his power, or aiming to curb his nuclear and missile ambitions. Pyongyang is expanding its capacity for coercive operations and using new tactics as it becomes more confident in its nuclear deterrent.²³

Even though South Korea’s attention is focused heavily on domestic politics, given the enormous stakes for the left and the right in the next presidential election, Seoul has no choice but to also focus on critical economic, security, and defense challenges that are not only growing in magnitude but also converging rapidly. For example, in the event of a major Taiwan conflict such as a full-scale Chinese invasion or a near-war crisis such as a Chinese naval blockade around Taiwan, Washington may ask Seoul and Tokyo to provide military assistance for multilateral operations. Thus far, however, even the conservative government in Seoul has been cautious in emphasizing the Taiwan issue, although during a trilateral U.S.-ROK-Japan trilateral meeting in November 2024, the three leaders stated, in part, that “we recognize that peace and stability across the Taiwan Strait is an indispensable element of security and prosperity in the Indo-Pacific region.”²⁴ Earlier in April 2023, during Yoon’s state visit to Washington, D.C., a joint statement also made reference to the importance of maintaining stability in Taiwan—a point which Beijing vehemently protested to both South Korea and the United States.²⁵ 

In sum, the range and magnitude of the security threats and challenges facing South Korea mean that Seoul will have little or no room for policy misjudgments or rapid U-turns. If a progressive candidate becomes president and decides to roll back advancements in Korean-Japanese relations, including enhanced security cooperation for domestic political purpose, for example, that would further weaken South Korea’s ability not only to respond more effectively to China’s accelerating power projection capabilities but also to buffer itself from highly uncertain turns in U.S.-ROK relations.

The Last Chance for Structural Political Reforms

Although Korean politics today is dominated by the upcoming presidential election on June 3, 2025, and how a new president is going to deal with a litany of crucial issues at home and abroad, the country faces a much deeper political malaise. The first and most pressing systemic problem is reducing the very strong power of the presidency. Since the constitution was last revised in 1987 after years of rule by former generals, the presidency has been limited to a single five-year term. What has happened since, however, is that all presidents exercised enormous power at the onset of their presidencies but ended their terms ignominiously or tragically including two presidents who were impeached (Yoon and Park) and former president Roh Moo-hyun who took his own life when he and his wife were being investigated for allegedly receiving illegal gifts and contributions. All others, apart from Moon Jae-in, left office with very meager public support.

Several previous presidents, such as Roh Moo-hyun and Park Geun-hye, stressed the need for revising the constitution but were not able to form a bipartisan consensus. While elder statesmen on the left and the right have called for revising the constitution, DP head Lee, the front-runner for his party’s nomination and the June election, stated on April 7, 2025, that “Constitutional revision is necessary, but ending the insurrection must come first”—strongly hinting that he is not supportive of a constitutional revision plebiscite that could be held in tandem with the upcoming June presidential election. This is because Lee believes that he is very close to becoming the next president and with the backing of a super-majority in the National Assembly through the first two years of his five-year term, he will be able to pass through his core policy and political priorities, and in the process, ensure the further downfall of the conservative PPP. But if he ignores a growing call for revising the 1987 constitution and assumes office in June, provided that he wins the presidency, he is likely to revert to taking political revenge that will exacerbate an already broken bipartisan structure in Korean politics.

If the inability to revise the current constitution is the biggest roadblock in Korean politics, the second crucial impediment is the top-down and extremely hierarchical nature of political party leadership and management both on the right and the left. This is because national politics at the highest levels, including the making and remaking of political parties, has been left to a small group of leaders or various kingmakers who emerge to become the indisputable party head and possible nominee for president. The give and take that is part of any major democratic system was ironically stronger under previous authoritarian governments in South Korea, since major opposition figures such as long-time democracy advocates Kim Dae-jung and Kim Young-sam, and to a lesser extent, Kim Jong-pil, who was Park’s number two for much of Park’s years in office, understood the necessity of compromise for societal cohesion. That generation of strong but open-minded political bosses has long been replaced by increasingly aggressive winner-take-all politicians with little or no regard for genuine bipartisan dialogue.

Today, rather than building strong institutions, including factions within the main parties, once a party is controlled by a particular leader, he or she will make sure to weaken or decimate internal opposition. The problem with this very heavy top-down system is that by the president’s third year in power, his power begins to weaken considerably—especially if the ruling party performs poorly in local elections, and more importantly, in National Assembly elections. As the opposition gears up for a bitter presidential fight, the only way to get the public’s support is to aggressively attack the party in power. Hence, a vicious cycle of intensifying “house cleaning” in the name of undoing the misdeeds of the previous government consumes the attention of a new government; but tragically, the new government is likely to face the same pace and depth of attack once their grip on power begins to ebb.

All previous presidents since the restoration of democracy in 1988 promised to lead through political dialogue and concessions, but none of the eight presidents who have led the ROK since then, including Yoon, acted on those promises once in office. The need for bottom-up political reforms has never been greater. Many political leaders and pundits agree that the time has come to revise the 1987 constitution, where the president serves a single five-year term while members of the National Assembly serve four-year terms but without term limits. More importantly, because presidential and National Assembly elections are not held at the same time, there is a lack of a stable election cycle in South Korea.²⁶ But a far more important question is whether the next Korean president will have the foresight, courage, and the long-term interest of the ROK to enact truly meaningful political reforms, or will the next president revert to the costly playbook of political retributions, triggering even deeper political divisions, and turning back on South Korea’s growing international clout and contributions to the global commons.

If past presidencies and vapid campaign promises can serve as a guide, the next ROK leader is also unlikely to put into place truly meaningful across-the-spectrum political reforms given the push to erase their predecessor’s policies and strategies and clamoring for “political justice.” Hence, if the political status quo remains unchanged, the ROK’s international competitiveness and its ability to navigate extremely difficult national security and foreign policy challenges will further exacerbate South Korea’s status as Asia’s second most advanced economy after Japan. 

The Causes and Consequences of Yoon’s Failed Presidency

Although the root cause of Yoon’s political demise lies squarely on his shoulders, the opposition DP also bears responsibility for pushing Yoon to the wall with some thirty impeachment motions since Yoon took office in May 2022.²⁷ To repeat, however, Yoon cannot blame anyone except himself for his disastrous decision to enact martial law on December 3, 2024 (rescinded by the National Assembly after a few hours) and the devastating impact it had on South Korea’s external relations and national security postures just as Donald Trump prepared to return to office in January 2025 and soon thereafter, triggering a global tariff war. Although the martial law fiasco was the principal trigger that led to Yoon’s impeachment, many political commentators speculated that his abrasive leadership style, ruling out contrasting views of his advisors within the presidential office, his refusal to engage in a one-to-one dialogue with the head of the opposition, and unparalleled controversies surrounding his wife, were going to inflict irreversible political damage to his presidency and the ruling party.²⁸ 

Amongst conservative voters, the area where Yoon received high marks was in his handling of foreign policy, especially his rapid pivot to strengthening ties with the Biden administration and making key strides in relations with Japan. Indeed, Yoon opted to take a risk by improving ties with Japan despite his approval rating hovering at around 20 percent during the first two years of his presidency.²⁹ Yoon met with then-Japanese Prime Minister Kishida Fumio twelve times from May 2022 until September 2024; out of all the foreign leaders Yoon met with over his term, he met with Kishida the most.³⁰ Japanese media covered Korean-Japanese relations during this period favorably, especially compared to the downturn in bilateral ties during most of Park’s (2013-2017) and Moon’s presidencies (2017-2022). As the Asahi Shimbun noted in September 2024 as Kishida prepared to step down, “Since taking office in 2022, Yoon has made it a diplomatic priority to mend ties with Japan and improve security cooperation to tackle North Korea’s military threats, bringing about a thaw in often icy relations between the neighbors.”³¹

Although it remains impossible to know just how future historians will judge Yoon’s legacy, his two and a half years in power (out of a total of a five-year term) will most likely be remembered as the worst since the restoration of democracy in 1988. As the JoongAng Ilbo noted right after the PPP suffered a huge loss in the all-important National Assembly election of April 2022, the root causes included perceptions of Yoon’s presidency’s inability to control inflation and arrest worsening income gaps, but “the most important element was a judgment on the president’s leadership style” and in particular, the fact that he “spoke for some 90 percent of the time during meetings” and didn’t listen to diverging viewpoints.³²

Harsh Realities and Harder Choices

Even though the writing on the wall of Yoon’s possible self-driven political crash was visible even early on during his presidency and especially after the ruling party’s massive loss in the April 2022 National Assembly election, the other side of the ongoing Korean political saga is the indisputable political culture reminiscent of Game of Thrones, where losers don’t accept losses and winners promise never to take political revenge, but do so at the very onset of their presidency. Unmatched gridlock between the president and the National Assembly headed by a super-majority opposition bloc, led by the DP, also contributed to South Korea’s deepening political malaise.

Most South Koreans believed that Yoon should be impeached for abuse of presidential powers, but the next president is going to lead a country that remains deeply divided not just between the left and the right, but also between generations, genders, and economic strata. While many advanced economies and democracies face deep political, economic, and security challenges (including key European states such as France and Germany), the magnitude of the problems confronting the ROK is arguably more dangerous given the nature of the Kim regime, the possibility of weakening U.S. extended deterrence towards South Korea (and Japan), and extremely polarized politics that make it virtually impossible to think about meaningful political compromises.

Although the Constitutional Court blamed Yoon for declaring martial law and argued that he had abused presidential authority that ended his presidency, the court also mentioned the opposition party’s own disregard for compromise and bipartisan politics. Given the significance of the court’s explanation, the most relevant portions are highlighted below.

Major policies set forth by the respondent [Yoon] could not be implemented due to the opposition party’s resistance, and the opposition unilaterally passed laws opposed by the government, prompting repeated exercises of the president’s veto power and repeated legislative re-approvals by the National Assembly. Amid these events, the respondent likely felt a heavy sense of responsibility, perceiving the nation’s governance to be paralyzed and national interest severely harmed by the opposition’s unilateral actions. The respondent’s assessment that the National Assembly’s exercise of power constituted an abuse or a cause of national paralysis should be worthy of political respect. However, the conflict between the respondent and the National Assembly cannot be attributed to one side alone. It is a political issue that must be resolved through democratic principles. Political opinions or public decisions on such matters must be expressed and made within the scope compatible with constitutionally guaranteed democracy.³³

Yoon’s impeachment must be understood by the conservatives as a last-minute warning, or a wakeup call, for a fundamental resetting of its policies and strategies. If a business-as-usual mentality prevails within the PPP, not only will it lose the June 2025 presidential election, but it may also become even more marginalized in the next National Assembly election that will be held in April 2027. The onus for change lies with the conservatives since two of their presidents have now been impeached. Finally, however, if the DP also believes that a supermajority in the National Assembly gives them the right to flaunt their power and ram through bills and policies that run counter to the public interest or to South Korea’s critical national security interests, they will also feel very strong headwinds from the public.

Should Lee become the presidential candidate of the DP and emerge victorious in June 2025, there is the possibility that he will enter the office as the most powerful president since the return of democracy in 1987. But Lee also faces enormous risks given that he continues to face numerous legal challenges, but “he might be able to become president despite his conviction in lower-level courts, as the prohibition does not go into force until all appeals are exhausted, and as president, he would have immunity from most criminal prosecution.”³⁴ It is very cliché to say that a country stands at a critical crossroads, but that is truly the case with South Korea today. Yoon’s impeachment and unparalleled divisions across Korean society must be seen by the left and the right not as an affirmation of their respective ideologies and political priorities, but as the last chance for South Korea to begin resetting its broken political system and fending off, to the best of its abilities, the worst external environment since the outbreak of the Korean War in 1950.