The Peninsula

Old Wounds, New Votes: Japan’s Changing Role in Korea’s Election Discourse

With the removal of President Yoon Suk Yeol from office, South Koreans head to the polls next week to pick his successor. The leading candidate is Lee Jae-myung of the Democratic Party, a progressive politician with a track record of being critical of Japan. In 2023, he engaged in a twenty-four-day hunger strike to protest the Yoon administration’s Japan policy. Lee also accused Japan of starting the “second Pacific War“ after the Japanese government authorized the release of wastewater from its Fukushima nuclear power plant. Given the difficult history of bilateral relations stemming from Japan’s colonial period, Japan has been a sensitive issue in Korean political discourse. While it remains to be seen who will be elected the next president of South Korea, Lee’s attempts to moderate his position suggest Japan may not be as controversial in Korean domestic politics as it has been.

Polling suggests that the public has thrown their support behind the progressive candidate. In a May survey conducted by Realmeter, about half of the respondents said they supported Lee, while only 35.6 percent selected Kim Moon-soo of the conservative People Power Party. When asked if they would maintain their choice, 82.3 percent of respondents affirmed that they would. Furthermore, a meta-analysis by Hankyoreh of 124 polls taken between December 2024 and May 2025 suggests that Lee could receive around 48.2 percent of the vote in a three-way race between him, Moon, and Lee Jun-seok of the Reform Party. The progressive leader has warned supporters not to be complacent, but members of his party are more optimistic. “Lee Jae-myung will receive over 55% of the vote,” said Representative Park Jie-won. “I expect the final result to be 60% for Lee, 30% for Kim Moon-soo, and 10% for Lee Jun-seok.”

While the public may be eager to turn the page on the Yoon administration, the presidential frontrunner seems interested in maintaining a positive bilateral relationship with Japan. In a May broadcast interview, he said that he wanted to deepen cultural and social ties with Japan despite differences over political and historical issues. “There is a misunderstanding in Korea-Japan relations,” said Lee. “There is a preconceived notion that I would be hostile towards Japan.” He admitted that issues like Dokdo and the legacy of Japan’s occupation of the Korean Peninsula retain high salience in South Korea. “However, I am very proactive and open in terms of cultural exchange and cooperation between Korea and Japan,” he said. Lee’s comments come after one of his advisors held an unprecedented meeting with White House officials. “I emphasized Lee’s view that the Korea-U.S. alliance is very important…and that we need to strengthen the cooperative relationship between Korea, Japan and the U.S.,” Kim Hyun-chong, a former deputy director of the National Security Office in the Moon Jae-in administration, told reporters.

At the same time, Lee has made other comments that hearken back to his more critical days. In the first televised presidential debate, he equivocated on how South Korea would balance its relationship with the United States and Japan on the one hand and China and Russia on the other. Lee also voiced support for the U.S.-ROK alliance and said that it should expand beyond security to include the economic sphere. “It is clear that we need to develop and deepen the Korea-U.S. alliance. Also, the Korea-U.S.-Japan cooperation system and security cooperation are absolutely necessary,” he said. But Lee added that “that doesn’t mean we should go all in on that.” When asked if Korea would become involved in a contingency in the Taiwan Strait, Lee was more cautious. “We must prioritize the national interest and avoid becoming too deeply involved in the China-Taiwan conflict,” he said. “The idea is to respect the status quo and maintain an appropriate distance.” While it remains to be seen what a possible President Lee may do, these comments equivocating relations with the United States and Japan on one side and China on the other do not exactly inspire confidence.

The shift by the progressives may also be a reflection of broader changes in Korean society. In a survey by the Asan Institute for Policy Studies, Korean respondents gave Japan a 4.52 out of 10 favorability rating—its highest level since the organization began tracking it in 2010. It is also a significant change from 2020 when respondents gave Japan a 1.99 rating. It is worth noting that the Korean public has never been particularly supportive of the Yoon administration’s efforts to resolve particularly sensitive issues with Japan. In one poll by Gallup Korea, 59 percent of respondents opposed the Yoon administration’s deal to resolve the issue of Japanese compensation for forced laborers. And yet, public opinion saw a recovery in recent years. It is hard to tell how long this recovery will last, as analysis from Genron NPO in Japan suggests Koreans still have lingering expectations of reciprocal efforts by Japan. And with Yoon’s martial law declaration and impeachment fresh on the public’s mind, the verdict on the legacy of the Yoon administration’s policies remains to be seen. But perhaps good relations between Seoul and Tokyo—a tall order—may be a more durable and positive part of his legacy.

The upward trend in bilateral Korea-Japan relations is helped by the Japanese side also wanting to sustain it. While the United States may be Japan’s first choice of partners, the Trump administration’s unpredictability makes working with other states like South Korea an imperative. Dr. Ryo Sahashi from the University of Tokyo says that a progressive administration in Seoul may not bode well for Tokyo. “But as confidence in the United States falls, there will surely be things on which the two countries can collaborate,” he said. “Japan should not be engaged only in managing its relations with the Trump administration; it should also show strategic flexibility and take new steps in its global diplomacy.” Influential members of the ruling Liberal Democratic Party (LDP) are open to working with Seoul. In a recent personal appearance in Washington, Director of the LDP’s Standing Committee on Economy, Trade, and Industry Shinjiro Koizumi noted that shipbuilding is an area the Trump administration has identified as a priority. “We believe that the U.S. and Japan could cooperate on that, or even include South Korean in that, potentially,” he said. “I think that that is an area with lots of opportunity.” While this did not serve as an official government stance, it suggests that Japanese leaders are eager to maintain the current friendly state of relations between South Korea and Japan.

The discourse on Japan amid the presidential election seems to suggest that Korean society is changing. Resolutions to outstanding problems like territorial disputes and historical issues remain out of sight, and bilateral relations could be thrown off by a black-swan event. But the staunchly progressive Lee’s attempts to moderate his position—and the public’s continued support for his campaign—suggests that Japan may be becoming less controversial in Korean domestic politics than it once has been. As Seoul and Tokyo look to welcome fifty years of diplomatic relations, political leaders on both sides should work to maintain the upward trend in relations.

Terrence Matsuo is a Non-Resident Fellow at the Korea Economic Institute of America. The views expressed here are the author’s alone.

Photo from Shutterstock.

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