Will Korea-Japan Relations Survive the Turmoil in Seoul?
By Daniel Sneider, Lecturer, International Policy at Stanford University, APP member
The Oriental Economist (Toyo Keizai), March 16,2025
This was supposed to be a year to celebrate the improvement of relations between South Korea and Japan. However, amid the turmoil in South Korea – and across the ocean in the United States -- the fate of relations between South Korea and Japan is increasingly uncertain.
On my recent visit to Korea, the streets of the capital city were filled on weekends with rival gatherings of fervent demonstrators.
In the boulevard leading from City Hall to the grand Gyeongbokgung Palace, rightwing supporters of the impeached President Yoon Suk-yeol, most of them pensioners, waved Korean and American flags. They proudly wore red baseball caps imitating the pro-Trump MAGA movement in the U.S.
Over by the National Assembly building, across the Han River, dense crowds of mostly younger people, many of them women, sang K-pop songs and marched in support of democracy and against the attempted martial law coup.
The decision of the Korean Constitutional Court on impeachment will not end these deep divisions in South Korea. But hopefully it will put set the country back on the road, through a new national election, toward forming a government capable of ruling the polarized country.
This could not come too soon. Korea is beset by twin threats. One one side, there is a nuclear-armed North Korea, strengthened by its military alliance with Russia and the ongoing support of China. On the other, there is a new danger in the form of an unpredictable isolationist Trump regime in the U.S. which could potentially withdraw the American armed forces that help protect South Korea and impose tariffs that could seriously damage the trade-dependent Korean economy.
Korea and Japan – strategic partners?
This is a year of milestones that could have celebrated the progress in relations under the conservative government of President Yoon and Prime Minister Kishida Fumio. It marks both the 60th anniversary of the treaty to establish diplomatic relations, and the 80th anniversary of the end of the war, which Koreans celebrate as a moment of liberation from Japanese colonial rule.
Instead, Yoon is effectively removed, impeached after his failed coup and facing potential imprisonment. Barring his unlikely return to office if the Court fails to uphold impeachment, an election within two months seems poised to bring to power the progressive Democratic Party, headed by populist politician Lee Jae-Myung. The Democrats have been deeply critical of Yoon’s Japan policy and Lee personally has been an unabashed spokesman for those who believe Japan has failed to confront the crimes of its colonial rule.
“Given Lee’s past record – his views, his arguments on Korea-Japan relations – a rollback of relations is quite predictable,” former Korean Amb to Japan, Shin Kak-soo, told me in Seoul.
In a separate conversation, a conservative former senior official with long experience in foreign affairs predicted that Lee will be “very adversarial” toward Japan. “He may not rattle the boat but basically Lee Jae-myung has a negative approach to Japan. He is more forthright about China and more critical of the U.S.”
That somewhat pessimistic prediction is easy to find in Tokyo as well. But Lee’s close advisors point to his pragmatic, rather than ideological, character to suggest that he will not seek to reverse the progress that was made and will be supportive of the U.S. security alliance.
Amb Cho Hyun, a former senior Foreign Ministry official who was deeply engaged in shaping Korea-Japan relations during the previous progressive government of Moon Jae-in, laid this out to this writer over breakfast in Seoul.
“We will not change what has been agreed upon between Korea and Japan,” Cho said, while acknowledging that he had opposed the Comfort Women agreement reached in 2015 between Park Geun-hye and the late Prime Minister Abe Shinzo.
“Our relationship has two bookends. On one end, we share enemies, a sense of threat, and are both allies to the United States. But at the other bookend, Japan did so many horrible things and denies doing it. They fail to educate their young people. On our part there is a sense of wounded nationalism. Diplomacy must operate between these two bookends.”
Cho and other progressive foreign policy advisors pointed to the failure of the Japanese government to reciprocate the unilateral decision of Yoon to create a fund to compensate the former forced laborers who worked in Japanese mines and factories during the wartime period. Japanese firms, who employed the workers, should now add to the fund, with the support and encouragement of the Japanese government, Cho and others suggest.
“Some people in the leadership of the Minjudang (Democratic Party) are fully aware of what went wrong,” Cho said. “They are willing to change their position. They would keep the unilateral announcement of Yoon regarding forced labor and maintain trilateral security cooperation. I hope the Japanese government may allow companies to join the funding. I have been arguing to Japanese friends that they need to talk to progressives.”
Some Japanese foreign policy experts share this cautious optimism. Tanaka Hitoshi, the former senior Foreign Ministry official who was a key architect of the outreach to North Korea under former Prime Minister Koizumi, voiced that to this writer in a recent interview.
“Even if the opposition takes power, we may still have a chance to preserve the improvement in relations,” Tanaka said. “The Democrats are against Japan and the US, the latter because of its support of the military regimes in Korea. But Japan-Korea relations and trilateral relations are the natural result of the current situation.”
The Trump factor enters the picture
Korean thinking about Japan has also now shifted due to the Trump factor. The angry exchange between the American leader and the Ukrainian President in the Oval Office had a similar shock effect in Seoul as in Tokyo.
Korean discussion of the need to develop an independent nuclear capability has spread from the right, where it has long been advocated, to the progressive camp. The new watchword among Koreans is “nuclear latency,” to follow the Japanese in creating a full nuclear fuel cycle, long opposed by the U.S. In that way, South Korea could move to reprocess spent fuel from its large number of nuclear power plants or create a uranium enrichment facility. A stockpile of fissile material would then allow South Korea to move towards nuclear weapons very quickly.
For now, Korean officials, like their counterparts in Japan, continue to talk confidently about their ability to offer sufficient concessions to keep the worst from happening. They point to the visit of Ishiba Shigeru to Washington as a model for Korea to follow.
Assemblyman Wi Sung-lac, who was the chief foreign policy advisor to Democratic party leader Lee in the last presidential election, believes the best they can hope for is a non-confrontational meeting which, like the one reached by Ishiba, at least reaffirms the alliance along lines of previous statements with the Biden administration.
“The Japanese still believe they will try to deal with Trump just as Abe did,” Wi said in an interview in his National Assembly office. “The joint statement has a preventative effect. When we come to that moment (of a summit), at minimum we hope we can have a similar document. It won’t be easy creating personal rapport between the two leaders, but we are going to try that. If we are not successful, then Japan, Korea and the Europeans will have to think this through.”
Some Koreans see Ishiba as a particularly good potential partner, given his greater willingness to deal with history issues and his support for improved relations with China and other Asian nations.
“Ishiba is really interested in trilateral relations – China, Japan, Korea,” Kim Joon Hyung, a progressive member of the National Assembly and a former senior Foreign Ministry official. “He is willing to approach China. I wish Ishiba survives longer.”
In some circles in Seoul, there is even talk of forging a strategic relationship with Japan to balance, if not counter, a U.S.-led Trump.
“Under the Biden administration we have some reason to work together on a trilateral basis because we had to deal with a rising China,” says Wi, a former senior foreign ministry official who was recently elected to the National Assembly. “That issue remains but now we have under the Trump administration new uncertainties and unpredictability that affect trade and bilateral relations and could affect both Japan and Korea.”
One idea that is quietly discussed in Seoul – with an eye toward Tokyo – is to use the expansion of the CPTPP (the Trade Pacific Partnership trade pact) to counter Trump’s tariff and trade wars. Korean application for membership could be accelerated and even linked to the European Union.
It may, however, be premature to talk of an anti-Trump alliance, some say.
“I am not sure Seoul and Tokyo policy makers have the incentive to work together (against Trump),” says Wi, who is likely to play a prominent role if Lee wins a presidential election. “Some Europeans like [French President Emmanuel] Macron or the Germans may try to launch this kind of idea with Asian nations. But Asian responses to that will be careful.”
That caution, however, may be blown away by Trump himself as he continues to assail the postwar international system.
