Takaichi and Lee need to be cautious about Tokyo-Seoul relations

This article, originally published by Pacific Forum, is republished with permission.

Bilateral relations between Japan and South Korea oscillate with alarming regularity. The 1968 dizzying highs of Kim Dae-jung and Keizo Obuchi (1998) have been matched by depressing lows reached a decade ago when Shinzo Abe and Moon Jae-in were in power.

A rebound in recent years, launched by former Prime Minister Fumio Kishida and then-ROK President Yoon Suk Yeol, was sustained despite changes in the top leadership in both countries.

The election of Sanae Takaichi as president of Japan’s ruling Liberal Democratic Party (LDP) and her now almost certain ascension to the position of prime minister threatens this happy moment. There is no guarantee of a reversal. Both countries continue to profess their interest in and support for a forward-looking partnership – but domestic politics, the perennial bugaboo, could undo the progress of recent years.

The end of the free fall in ROK-Japan ties and the pursuit of positive relations owes much to the courage of the now-discredited Yoon. He actively promoted stronger ties with Japan – a conservative instinct in Seoul that, nevertheless, runs counter to South Korean sentiment more broadly.

That effort was assisted by the United States, which actively promoted bilateral and trilateral cooperation among the three nations. Then-President Joe Biden hosted Yoon and Kishida at an August 2023 summit at Camp David where they pledged to deepen collaboration in deterring North Korean provocations and incounteringthe rising influence of China.

The June 2025 election of Lee Jae Myung – like Moon Jae-in, a member of the progressive Democratic Party – was cause for wariness given Lee’spast statementson Japan. However, he and his government havelargely insistedon consistency in their bilateral ties with Tokyo.

The election of Sanae Takaichi as Japan’s new prime minister, replacing the struggling Shigeru Ishiba, will have the benefit of removing the ambiguity about the near-term prospects for Japan’s leadership. But in Seoul it revives memories of the late Abe.

For allhis accomplishmentsas a statesman, and for all the esteem with which he is regarded in much of the Indo-Pacific – in India, in Southeast Asia, and in Washington – Abe’sactions and statementson matters of historical dispute left him deeply unpopular in both Koreas.

At one point a decade ago, South Koreans rated Abeless favorablythan Kim Jong Un – and 2014-2015 was far from an optimistic time in inter-Korean relations. Even before Moon’s time in office, his conservative predecessor Park Geun-hye largely avoided public appearances with Abe unless they were brokered by the US administration.

The connection between Takaichi and Abe is inescapable. Takaichi is a conservative nationalist, a strong supporter of the former prime minister, and has embracedmany of his policies. She

• supports a higher international profile for Japan and a stronger military, with the requisite spending to sustain it;
• warns of China’s predatory policies and the threat they pose not only to Japan’s security but that of the entire region;
• backs Taiwan; and
• seeks a strong partnership with the United States.

She has acknowledged theimportanceof bilateral Japan-ROK ties, as well as trilateral cooperation that includes the United States.

She called for the “deepening” of Japan-ROK relations at a candidate debate during the campaign and “strengthening” of trilateral cooperation given the increasingly challenging regional security environment.

While those comments are reassuring, relations with South Korea could be threatened by a backlash from her political instincts. She regularly visited Yasukuni Shrine, which South Koreans (and others) consider a symbol of Japan’s militarist past. Those visits square with her belief that Japan waged “a defensive war” in World War II and has been unjustly punished for doing so.

To her credit, she has said thatfuture visitswould depend on circumstances; hopefully, among them is their impact on the bilateral relationship.

Still more offensive to South Korean sensibilities is her belief that the Japanese government shouldsend Cabinet ministersto the February 22 Takeshima Day ceremony hosted by Shimane Prefecture.

The prefectural government hasrequesteda top-level official for the annual event which marks Japan’s claim to the islands, known as Dokdo to Koreans. (A lower-level official has attended since 2013 precisely to avoid inflaming that sentiment.)

Takaichi has adifferent perspective. “There is no need to be cautious,” she said at a debate. “There’s no need to read the room. It’s Japanese territory, part of Shimane Prefecture. I believe this is something all of us should know and understand.” That position is sure to incense South Koreans.

There is little that can remedy this situation. The most important factor is deep commitment to cooperation among the three by the US president, which would set the tone for his national security bureaucracy.

Each layer would press his or her counterpart(s) to pursue bilateral or trilateral relations. The president’s involvement is especially important because demanding a similar outlook from his counterpart would make this a priority for their respective national security community as well.

Absent that push, there is a very good chance that South Koreans and Japanese will both hesitate, worried about the commitment of the other to the rapprochement process. Both will be on the lookout for hedging or behavior that confirms prior beliefs that the other is an unreliable partner.

History suggests that there will be ample opportunity for those prejudices to be validated.

Rob York(rob@pacforum.org) is director for regional affairs at Pacific Forum.

Brad Glosserman(brad@pacforum.org) is Director of Research and Senior Advisor at Pacific Forum.