June 23, 2025
TOKYO – Japan and South Korea marked the 60th anniversary of the normalization of their diplomatic relations on Sunday. The two countries once interacted as an industrialized country and a developing country, but they have now become equal partners, on par with each other in economic terms.
They are also facing common challenges, including the drastically changing international situation and populations that are rapidly graying with chronically low birthrates.
It will be essential for Japan and South Korea to deepen their future-oriented cooperation while carefully dealing with historical issues that could trigger conflicts.
“There are many fields in which we can cooperate by sharing knowledge. We want to further broaden the areas for Japan-South Korea cooperation and pass the baton of cooperation to future generations,” Prime Minister Shigeru Ishiba said at a ceremony in Tokyo on Thursday to commemorate the 60th anniversary of the normalization of diplomatic ties. Ishiba referred to regional revitalization and measures to address the low birthrate, issues on which he is focusing.
The prime minister called on South Korea to work together on issues where the two countries share common interests, apparently in consideration of the fact that South Korea’s President Lee Jae-myung, who took office earlier this month, is promoting a pragmatic approach by focusing on practical benefits.
South Korea was one of the poorest countries in the world following the Korean War. However, it managed to achieve high economic growth, known as the “Miracle on the Hangang River,” partly due to the normalization of diplomatic ties with Japan.
The Treaty on Basic Relations between Japan and the Republic of Korea and The Agreement on the Settlement of Problems concerning Property and Claims and on Economic Cooperation between Japan and the Republic of Korea were both signed on June 22, 1965. Via these agreements, the two countries acknowledged that the issue of claims between them had been settled, under the premise that Japan would provide South Korea with economic cooperation worth $500 million — about twice the size of South Korea’s national budget at that time — establishing the foundation of later Japan-South Korea relations.
Currently, the two countries have about the same level of gross domestic product per capita. In the field of semiconductors, Japan has advantages in materials and manufacturing equipment while South Korea has strengths in production, making the two countries increasingly mutually dependent.
Japan and South Korea also share the problem of a poor working environment for women, which is considered one of the factors behind the low birthrate in both countries. Japan ranked 118th among 148 countries in the Global Gender Gap Report by the World Economic Forum, while South Korea stood at 101st.
‘Complementary partners’
President Lee reportedly expressed a sense of crisis over his country’s low birthrate when he met Koichi Aiboshi, a former Japanese ambassador to South Korea, in December 2021.
“[South Korea] has spent a considerable amount of budgetary funds on measures to counter the low birthrate, but the situation has failed to see any progress,” Lee reportedly said. He also told Aiboshi that he would like to find out what is done in other countries to use them as references.
“To collaborate with President Lee, who is focusing on the economy, it will be important to explore specific cases for cooperation,” Aiboshi said.
In a congratulatory video message for an event held in Seoul on June 16 to mark the anniversary of diplomatic relations, Lee said, “South Korea and Japan are key partners who must cooperate closely in responding to a rapidly changing global landscape.”
In his first summit meeting with Ishiba in Canada later in the week, Lee also said Japan and South Korea are “complementary partners.”
South Korea experienced a political vacuum for about six months due to the impeachment and removal of former President Yoon Suk Yeol. It is an urgent task for the country to respond to the administration of U.S. President Donald Trump’s tariff measures and demand to increase defense spending as well as a military alliance between Russia and North Korea.
Like Japan, South Korea relies on energy imports, and stability in the East and South China Seas and the Middle East is directly linked with its economy.
According to Japan’s Defense Ministry officials, the ministry examined a plan to provide maintenance work in Japan for South Korea’s F-35 fighters, as a symbol of improved bilateral ties during the rule of former President Yoon’s administration.
In the Asia-Pacific region, maintenance bases for F-35 jets are located only in Japan and Australia. South Korea is cautious about defense equipment cooperation with Japan, so it currently has to take its F-35 fighters to Australia for maintenance.
Changing public opinion
South Korea’s political left wing, which supports President Lee’s administration, is strict about historical issues and tends to be conciliatory to China and North Korea. Therefore, Japan remains wary of the new administration.
However, in an opinion poll conducted by South Korean’s Korea JoongAng Ilbo this month regarding the country’s diplomatic relations with Japan, 49.6% of respondents sought future-oriented cooperation in such fields as the economy, technology, security and the environment. This exceeds the 31.5% who sought the resolution of historical issues.
The groundwork is nearly completed to take cooperation between the two countries to a new level.
