A meeting between the leaders of South Korea and Japan this weekend was hailed as the start of a new stage in the relationship between the two countries. South Korea's new president, Lee Jae Myung, and Japanese Prime Minister Shigeru Ishiba talked for nearly two hours in Tokyo before publicly pledging to leave aside their differences and work as close partners.

In the first joint statement in 17 years, they pledged to develop "stable, future-oriented" ties in many areas, including artificial intelligence, industry and denuclearization of the Korean Peninsula. Defense ministers of the two nations are now scheduled to meet in Seoul on September 8 — the first meeting of that kind in over a decade.

Moreover, Tokyo and Seoul want to set up a joint task force to deal with common challenges such as raising the birth rate and revitalizing rural regions.

'I feel like we are close friends': South Korea's Lee

The Tokyo summit seemed to have a remarkably positive atmosphere, at least between the two leaders.

"This is our second meeting. I feel that we are close friends," South Korea's Lee said of Ishiba, adding that Japan is "the most suitable partner" to tackle urgent issues. And this is somewhat of a turnaround for Lee, who decried his own predecessor Yoon Suk Yeol as a "Tokyo puppet" for taking part in a similar meeting in 2023.

Since taking office two months ago, however, Lee has taken a much friendlier stance toward Japan — even describing it as an "indispensable partner" on August 15, the exact anniversary of the Korean Peninsula's liberation from Japanese rule in 1945.

"I came to Japan today with the conviction to boldly break away from past practices and pursue pragmatic diplomacy," Lee said in Tokyo.

Japanese Prime Minister Ishiba echoed this sentiment.

"Because we are neighbors, there are difficult questions between us. But we will pursue a consistent political course," said Ishiba.

United front against Donald Trump

Japan and South Korea's push to upgrade ties is likely a response to the unpredictable foreign policy of US President Donald Trump, combined with North Korea and China forging closer ties with Russia. In Tokyo, Lee and Ishiba spoke of an "increasingly difficult strategic environment." 

Trump has already imposed a 15% tariff on Japanese and South Korean exports to the US while demanding investment in the US and calling for Washington's allies to give more money for defense.

Seoul and Tokyo seem to no longer be sure if the US will meet its obligations as an ally in case of a conflict with China or North Korea. The weekend summit in Tokyo is aimed at triggering a "positive cycle" between the two of them and the US.

This is especially important for Lee, who is flying out of Japan to meet Trump in Washington on Monday.

"Both countries are worried that the US is pulling back from being the major protective power, but also from being a reliable trade partner. This is why it makes sense to talk, cooperate and develop a joint strategy of facing Americans," said Frederic Spohr, the Seoul-based representative of Germany's Friedrich Neumann Foundation, which is aligned with the neoliberal Free Democratic Party.

New times bring new ideology

Agreements between Japan and South Korea are vulnerable to power changing hands in Seoul — new South Korean presidents often tend to overturn pledges made by predecessors upon taking office. However, Lee told Japanese newspapers that he would not undo agreements concerning historical disputes — including a controversial compensation fund for forced laborers during World War II.

And Lee's political rivals inside South Korea can hardly attack him for improving ties with Japan — the opposition conservatives share the same goal. He is also capitalizing on a general positive shift toward Japan in South Korea.

"Anti-Japanese resentment and slogans are growing less and less effective politically," said Spohr. "In many segments of the population, especially with young people, China is seen as a threat and Japan is now relatively popular."

South Koreans are also the biggest single group of foreign tourists visiting Japan — 8.8 million South Koreans traveled to the country in 2024.

Ishiba careful not to provoke South Korea

In turn, Japanese PM Ishiba also seems to be distancing himself from other Japanese conservatives — including the ones in his own Liberal Democratic Party (LDP) — by not making excuses for Japan's history of war and colonialism. Ishiba has also decided against visiting the controversial Yasukuni shrine, which honors Japan's 2.5 million war dead, including convicted war criminals. 

In a speech marking the end of World War II on August 15, Ishiba notably used the word "regret" when speaking about his country's history.

"We will never repeat the devastation of war," he pledged. "We will never move away from the right path."

It's also worth pointing out that neither Lee nor Ishiba plans to attend the big military parade in Beijing this September, which is set to mark the end of the war in Asia. Russian President Vladimir Putin and dignitaries from all over the continent are expected to travel to China for the event.

Is Ishiba here to stay?

Still, the atmosphere between the two nations could get chilly once again if Ishiba is forced to vacate his post as the head of the Japanese government. The prime minister's grip on power has been weakened by the LDP's loss at the parliamentary election in July, and his party is due to decide what the fallout of this defeat will be in early September.

The conservative Ishiba could be replaced by nationalist Sanae Takaichi. She has already announced she would visit the Yasukuni shrine as prime minister, which would be seen as a provocation in Seoul.

This article was originally written in German.