As Prime Minister Fumio Kishida of Japan arrived in Seoul on Sunday to nurture a fledgling détente between the neighboring countries, South Koreans were waiting intently for what he had to say about Japan’s brutal colonial rule of the Korean Peninsula in the early 20th century.
Mr. Kishida’s two-day trip follows a visit in March by South Korea’s president, Yoon Suk Yeol, to Tokyo. It means that shuttle diplomacy between two key U.S. allies is back on track after regular exchanges between the countries’ leaders ended abruptly in 2011 over historical differences.
Few countries welcome the thaw as much as the United States. For years, it has been urging Tokyo and Seoul to let go of past grievances and cooperate more, both to deter the nuclear threat from North Korea and to help Washington rein in China’s economic and military ambitions.
When he met Mr. Yoon in Washington late last month, President Biden thanked the South Korean leader for his “courageous, principled diplomacy with Japan.”
In March, Mr. Yoon removed a roadblock in relations with Japan when he announced that South Korea would no longer demand Japanese compensation for victims of forced labor during World War II, but would create its own fund for them. Mr. Yoon said that Japan should no longer be expected to “kneel because of our history 100 years ago.”
The olive branch to Tokyo is part of Mr. Yoon’s broader efforts to reshape South Korean diplomacy, aligning his country closer to countries with “shared values,” especially the United States, on such things as supply chains and a “free and open” Indo-Pacific.
Mr. Yoon’s diplomatic concessions were a political boon for Mr. Kishida at home but costly for Mr. Yoon in his own country, where South Koreans accused him of “traitorous, humiliating diplomacy.” His domestic critics say he gave too much and got too little in return from Japan, which they say has never properly apologized or atoned — a common complaint among many other Asian victims, especially in China and North Korea, of Japan’s World War II aggressions.
To many South Koreans, what matters most in relations with Tokyo is how Japanese leaders view its colonial era, a time when Koreans were forced to adopt Japanese names; when schools removed Korean language and history from the curriculum; and when tens of thousands of Korean women were forced into sexual slavery for Japan’s Imperial Army. They are likely to assess Mr. Kishida’s visit on whether — and how directly — he will apologize for that past.
“South Koreans are all ears for what Kishida will say about the history,” said Lee Junghwan, an expert in Korea-Japan relations at Seoul National University. “If he says something vague, just making roundabout references to statements from the past Japanese leaders, as he likely will, it may not go down very well.”
Mr. Yoon’s government has tried to sell South Koreans on his outreach by raising hopes that Japan would reciprocate — for instance, by letting Japanese companies that benefited from wartime forced labor make voluntary contributions to the South Korean victims fund. In recent weeks Tokyo has lifted export controls imposed on South Korea after the dispute over forced labor erupted in 2018 and started the process of putting the country back on its “white list” of preferential trade partners.
But if Mr. Kishida fails to deliver on South Koreans’ expectations on history, “it’s going to cast a shadow over all that they’ve managed to accomplish in the last few months,” said Daniel Sneider, a lecturer of East Asian studies at Stanford University. “It’s more important what he says about the past than whether or not, for example, Japanese companies eventually contribute to the fund for the Korean forced laborers.”
The Seoul trip is a test of leadership for Mr. Kishida, and an opportunity to show that he can expand on Mr. Yoon’s efforts toward reconciliation, analysts said.
“An unusual window exists for him to demonstrate bold statesmanship and to shift the seemingly endless vortex of negativity between Japan and Korea,” said Prof. Alexis Dudden at the University of Connecticut, an expert on Korea-Japan relations.
For instance, Mr. Kishida could pay a reflective visit to any of Seoul’s monuments to the suffering that Koreans endured under Japanese occupation, Professor Dudden said, comparing such a move to a 1970 visit to Poland by the German chancellor, Willy Brandt. But doing so — let alone kneeling before a monument, as Chancellor Brandt famously did in Warsaw — may be too much to ask from Mr. Kishida, given that his country’s right-wing nationalists are poised to “make him pay for anything they define as being weak on Korea in the mudslinging memory wars between the countries,” she said.
The last time a Japanese leader visited South Korea, the relationship was so bad that the prime minister, Shinzo Abe, remained pointedly seated during a standing ovation as North and South Korean Olympians marched together during the opening ceremony of the Pyeongchang Olympics in 2018.
Mr. Kishida, traveling amid a more amicable mood, has said he wanted to “add momentum” to the improving relations. But few analysts believed that decades-long tensions will disappear easily, given political pressure at home for both leaders.
“More than 90 percent of our bilateral relationship is domestic politics,” said Kunihiko Miyake, a former Japanese diplomat. “So South Koreans cannot pardon us. They will continue to pressure us, and they want to maintain these sort of relations forever by moving the goal posts.”
For his part, Mr. Kishida needed the support of right-leaning politicians in Japan, who are among the most influential in selecting party leaders. Mr. Miyake said he would be “surprised” if Mr. Kishida “suddenly makes overly conciliatory remarks vis-à-vis South Korea.”
Yet Tokyo may be considering how to navigate subtle pressure from the United States, analysts said.
Mr. Biden’s repeated praise of Mr. Yoon’s diplomacy was “a kind of message not only to President Yoon but to Kishida,” said Junya Nishino, a law professor at Keio University in Tokyo. Mr. Nishino added that recent electoral victories by Mr. Kishida’s party in special elections last month might also give him “more diplomatic space.”
Mr. Yoon’s own determination to improve ties with Tokyo is backed in part by shifting public opinion in South Korea. In recent surveys, China has replaced Japan as the country regarded least favorably, especially by younger people.
But misgivings about Japan have deeper roots among South Koreans than Mr. Yoon may like to believe, analysts say. A survey taken in March found that 64 percent of South Korean respondents said there was no need to hurry to improve ties unless Japan changed its attitude on history.
Ms. Dudden cautioned Seoul, Tokyo and Washington against treating “history as mere background music to the present and irrelevant to how it informs immediate concerns — in this instance, standing firm on North Korea and increasingly on China, too.”
As the history of the bilateral ties between South Korea and Japan has repeatedly shown, a reconciliatory move over one historical dispute accomplishes little if another dispute, such as over the territorial rights over a set of islets between the two nations, is rekindled.
“The history issues have a way of coming back and biting you in the rear end,” Mr. Sneider said. “These aren’t just issues of short-term public opinion. They are matters of identity in Korea.”
