Former South Korean President Yoon Suk Yeol will likely be remembered for a troubled legacy marked by domestic controversies, unpopular policies, and his shocking and ill-fated declaration of martial law. However, amid the many missteps and political scandals that defined his presidency, there remains one domain in which Yoon made tangible progress: diplomacy. Though much of his foreign policy agenda may be rolled back or abandoned in the wake of his premature departure, he nonetheless achieved a number of diplomatic successes that had eluded his predecessors.
Chief among Yoon’s accomplishments was his bold move to thaw South Korea’s long-frozen relationship with Japan — an achievement that helped establish the foundation for an unprecedented trilateral partnership with the United States. For decades, historical grievances and territorial disputes have kept Seoul and Tokyo at arm’s length, often preventing meaningful dialogue. Yoon, however, made the politically risky decision to pursue reconciliation, despite strong public opposition and deep-seated mistrust.
Yoon’s willingness to confront sensitive issues — most notably, Japan’s handling of wartime atrocities and the Fukushima wastewater release — distinguished him from previous leaders who largely avoided the Japan issue due to the political costs. He was the first Korean president in over a decade to visit Tokyo for a summit, and he welcomed Japanese Prime Minister Fumio Kishida to Seoul in return. In total, the two leaders met a record 12 times in just over a year, a stark contrast to the years of mutual avoidance that came before.
The effect of this rapprochement was profound. Public and private exchanges between the two countries surged, with tourism and cultural exchange recovering quickly. More importantly, the warming of Seoul-Tokyo relations laid the groundwork for a stronger trilateral alliance with Washington — an essential move in the face of the growing strategic alignment between North Korea, China and Russia.
In August 2023, this new trilateral partnership was formalized at the historic Camp David summit, where Yoon, Kishida and then-US President Joe Biden pledged closer military and diplomatic coordination. Since then, officials from the three nations have met over 80 times, conducting joint military exercises across a range of domains, including missile defense, anti-submarine warfare and cybersecurity. For a moment, it seemed as though South Korea had stepped firmly into the role of a responsible middle power, one capable of shaping regional security dynamics and punching above its weight on the global stage.
This ambition was further reflected in Yoon’s Global Pivotal State vision — a foreign policy doctrine aimed at transforming Korea from a regional player into a globally engaged actor. Yoon argued that Korea should no longer be constrained by geography or historical burdens, and he sought to embed Seoul more deeply in multilateral institutions and global security discussions. He was the first Korean president to attend a NATO summit, and his government subsequently opened a permanent mission to NATO headquarters in Brussels. South Korea also aligned more closely with the West on global issues, providing humanitarian aid and non-lethal military assistance to Ukraine, and hosting the inaugural Korea-Pacific Islands Summit in 2023.
Yoon’s Indo-Pacific Strategy closely mirrored Washington’s, emphasizing democratic values, free trade and resistance to authoritarianism. Though this value-driven diplomacy was criticized by some as overly pro-American, it did help position Korea as a committed stakeholder in the liberal international order — at a time when democratic norms are under strain worldwide.
Yet, just as Yoon’s diplomatic vision was gaining traction, political reality began to catch up. All three leaders who engineered the trilateral partnership — Yoon, Kishida and Biden — are either out of office or facing uncertain futures. With Yoon’s ouster and the upcoming June 3 election likely to bring the main opposition Democratic Party of Korea back to power, South Korea’s foreign policy may shift dramatically. The Democratic Party has traditionally taken a more nationalistic and cautious approach to diplomacy, particularly with Japan. Already, there are concerns that the hard-earned gains in Seoul-Tokyo relations may unravel, especially given Japan’s reluctance to fully acknowledge or compensate for its wartime actions.
Meanwhile, Prime Minister Kishida’s successor, Shigeru Ishiba, appears too consumed by domestic challenges to prioritize regional diplomacy. And in Washington, the return of Donald Trump could spell the end of Biden’s steady, alliance-based foreign policy. Trump’s known disdain for multilateralism and unpredictable diplomatic style threatens to weaken the very foundations of the trilateral pact built under his predecessor.
The risk is that, in the absence of strong leadership, the trilateral alliance will falter just as China, Russia and North Korea deepen their own military cooperation — fueled in part by the ongoing war in Ukraine and the erosion of global norms. Should Korea’s foreign policy retreat into passive, inward-looking nationalism, it could miss a critical opportunity to shape the emerging security architecture of the Indo-Pacific.
Yoon’s disgraceful exit from office, caused by the controversial imposition of martial law, casts a long shadow over his administration. Yet, it would be shortsighted to dismiss the progress he made in foreign affairs. His diplomatic legacy — however fragile — demonstrated that South Korea can rise above historical grievances and assert itself as a credible player in global geopolitics.
In the end, President Yoon will be remembered more for his failures than his successes. But when it comes to diplomacy, his tenure offered a glimpse of what South Korea could become: not merely a regional power caught between giants, but a Global Pivotal State capable of shaping history, not just responding to it.
Lee Byung-jong
Lee Byung-jong is a former Seoul correspondent for Newsweek, The Associated Press and Bloomberg News. He is a professor at the School of Global Service at Sookmyung Women’s University in Seoul. The views expressed here are the writer’s own. — Ed.
