Hopes that Japan and South Korea might finally be able to build new bridges through a summit of their leaders on the sidelines of the Tokyo Olympic Games have been dashed after Seoul announced that President Moon Jae-in would not be going to the opening ceremony on Friday.

The northeast Asian neighbors have long been at loggerheads over differing interpretations of their shared history, most notably during Japan's colonial rule of the Korean peninsula from 1910 through 1945, but bilateral ties have worsened since Moon became president in 2017.

A series of legal claims by former forced laborers and "comfort women" — the euphemistic term for women forced into sexual slavery for the Imperial Japanese military during the occupation — has deepened the already entrenched nationalist factions on both sides of the divide, leaving no room for compromise.

That deepening chasm has caused alarm in Washington, which traditionally sees Japan and South Korea as its two most important security allies in the region. Since coming to power in January, US President Joe Biden has put pressure on both Moon and the administration of Japanese Prime Minister Yoshihide Suga to put their differences aside in order to present a united front to the challenges posed by an increasingly belligerent China and an unpredictable and nuclear-armed North Korea.

Tepid response from Japan

South Korea had, in recent weeks, indicated that Moon would be willing to travel to Tokyo if his Japanese counterpart would agree to a summit during which issues of substance might be addressed and solutions reached. Japan's reaction, however, was lukewarm.

"The Biden administration has struggled to get Seoul and Tokyo to prioritize shared geopolitical concerns," Leif-Eric Easley, a professor of international studies at Ewha Woman's University in Seoul, told DW. "The Olympics should have been a reconciliatory action-forcing event for the feuding US allies. Instead, South Korea-Japan relations have worsened because of a sequencing problem."

"The Moon administration wanted a summit to disentangle historic issues from contemporary trade and security cooperation," Easley said. "But the Suga government expected South Korea to first address its domestic court cases over wartime compensation so the legal foundation of bilateral exchanges could be restored."

South Korean court cases over compensation for historical wrongs are a "line in the sand" for Suga, who has attempted to put the burden of a solution entirely onto Seoul, the professor explained.

"This mismatch produced a series of diplomatic insults and failure to arrange a Moon-Suga summit during the Tokyo Olympics," he said.

Lewd remark the final straw

The final straw for Seoul, however, appears to have been a deeply undiplomatic comment from the deputy head of the Japanese embassy in Seoul.

During a lunch meeting with a South Korean reporter last week, Hirohisa Soma said Moon's efforts to improve relations with Tokyo while Japan attempted to successfully host the Olympics and deal with the pandemic amounted to "masturbation."

Seoul lodged an official protest, and the Japanese government has confirmed that it will replace Soma for his comments. The damage was done, however, and the South Korean Blue House announced on Monday that Moon would not be going to Tokyo, with a government spokesman confirming that Soma's comments had been a "significant obstacle" to the diplomatic move.

Korean media has been strongly critical of Japan's perceived indifference to Seoul's olive branch, with the JoongAng Daily accusing Tokyo of "high-handedness" and creating a "negative environment."

'Face history squarely'

In an editorial, The Korea Times demanded that Japan "face up to its history squarely and make sincere efforts to build trust with Korea."

Media in Japan have reported that Moon has canceled his trip, but are far more focused on the Olympics and rising coronavirus numbers. Those two issues are also likely to be the government's primary concerns just days before the opening ceremony.

"Suga is desperate for the games to be a success, both because Japan is the host nation and as he is facing an election before the end of the year and will be hoping for a positive response at the polls if everything goes off smoothly," said Hiromi Murakami, a professor of political science at the Tokyo campus of Temple University.

"For Japan, the absolute priorities are closer to home than the disagreements with South Korea, for which he is unlikely to win any public support, especially if he is seen to be giving in to pressure from Seoul," she said.

Suga is also acutely aware that Moon's administration will come to an end next spring, Murakami said. "A lot of people in Japan are just waiting for a government that they feel it is difficult to work with to leave office in the hope that they are better able to negotiate with whoever comes in next," he added.

Strategic patience

Easley agrees that Japan is exercising strategic patience in the anticipation that bilateral relations might cool down and experience a new start next year.

"Moon seeks a compromise with Japan but hasn't made much progress on the domestic politics of the issue, so Tokyo may wait until after elections in Japan and South Korea to deal with Moon's successor," he said.

And the outlook is not entirely bleak, he added, as the two governments are still clearly talking about issues of shared concern. 

"South Korea-Japan ties are severely strained but not irreparably damaged," he emphasized. "Much cooperation continues, including frequent trilateral meetings with the United States to coordinate foreign policies."

On Tuesday, Tokyo and Seoul agreed to continue efforts to resolve the issues that have caused the rift. Senior diplomats from the two nations also met in Tokyo on Wednesday with their US counterpart to discuss regional and global matters.