On March 16, 2023, the leaders of Japan and South Korea met in Tokyo for what was hailed as a groundbreaking summit. Held a decade since the last high-level talks, the discussions were welcomed as the start of a new era of relations between the two countries.
However, behind the warm words, there’s also a great deal of skepticism about the news. This certainly isn’t the first time the countries have hailed a fresh start in ties. Many therefore wonder whether this will in fact change the dynamics of what is a highly complex relationship. So, just why are the relations quite so complicated? And, after many decades of effort, will this summit really mark a lasting breakthrough?
We often think of international relations in terms of friends and enemies, allies and adversaries, which states work together and have close ties, and which are seen as rivals, competitors, or even threats to each other. Of course, the world isn’t quite so simple. Allies differ and even the closest partners occasionally have serious disputes. Likewise, states with hostile relationships may go through periods of detente, or rapprochement, when relations warm. But, overall, we nevertheless tend to see the world in terms of blocs.
But some countries have an altogether much more complex relationship. While they may share common economic and strategic goals, and even broadly similar political ideologies, they have a strained bilateral relationship. One of the best examples is Japan and South Korea. Despite being part of the broader family of economically advanced liberal democratic states, and sharing common concerns over many regional and international issues, these two countries have one of the most challenging relationship between any partners in modern international relations.
Japan and South Korea: Location, Population and Economies
Japan and the Republic of Korea lie in East Asia. At 380,000 square kilometers, or around 145,000 square miles, Japan is the 62nd largest country in the world. In contrast, South Korea is 100,000 square kilometers, or 39,000 thousand square miles, making it the 107th largest UN member. At their closest point, the countries lie just 50 kilometers, or 30 miles, apart.
The population of Japan stands at around 125 million, twice the size of South Korea at 52 million. Economically, the two countries are classed as advanced high-income economies. Overall, Japan is the third largest economy in the world and South Korea is the 10th. But while Japan was traditionally wealthier than South Korea, this is changing. While per capita GDP stands at $42,000 in Japan, it’s now reached $47,000 in South Korea.
The Japanese Occupation of Korea, 1910-1945
Japan and South Korea have a long and complicated history stretching back thousands of years.
During that time, Korea often acted as a buffer between Japan and China—the two regional powers. This came to a head in the late 19th century, when the two countries fought to control Korea. Having won, Japan formally annexed the country in 1910. This marked the start of what would become a brutal colonial occupation.
As well as curtailing fundamental human and civil rights, the Japanese military government launched a policy of forced assimilation. In addition to banning the use of the Korean language in schools, and effectively forcing Japanese names on many people, tens of thousands of Japanese families were settled on the peninsula and many Koreans moved to Japan in search of work. On top of this, any attempt to rebel was brutally put down. For example, an uprising in 1919 saw 50,000 people arrested and over 7,000 killed.
In the 1930s, Japan and China went to war again. As a result, efforts to integrate Korea were stepped up. These abuses then escalated during the Second World War, when almost a million Korean men were forced to labor for the Japanese war effort. Meanwhile, hundreds of thousands of women were forced into sexual slavery—the so-called “comfort women.”
The Partition of Korea and the Creation of the Republic of Korea
In August 1945, Japan was finally defeated and forced to withdraw from Korea, thus ending its 35-year occupation. However, instead of becoming a fully independent state, the peninsula was now divided politically between the United States and the Soviet Union.
This came to a head in June 1950, when the communist North—the Democratic People’s Republic of Korea—backed by the USSR and communist China, invaded the Republic of Korea in the south. In response, the United States, operating under a UN Security Council mandate, stepped in, marking the start of the Korean War—a conflict that would eventually cost 3 million lives. This came to an end in 1953 with an armistice disagreement that cemented the peninsula’s Partition—a highly destabilizing division that lasts until today. Meanwhile, the United States now undertook to protect Japan and South Korea, signing security pacts with them both in 1951 and 1953.
Japan and South Korea Establish Diplomatic Relations
Although Japan and South Korea were now aligned with the United States, their bilateral relationship remained highly strained. While formal peace talks began in 1951, an agreement proved impossible. Despite pressure from Washington, South Korea found it hard to overcome the legacy of Japanese colonialism.
However, by the mid-1960s, things were changing. In 1965, they finally agreed to a treaty. In return for Japan providing considerable economic support to South Korea, and a one-off lump sum payment to settle all claims arising from the occupation, they finally established diplomatic relations.
Efforts to Improve South Korea-Japan Relations After 1965
Over the course of the following years, relations between Tokyo and Seoul continued to improve. As well as their ties to the United States, growing trade saw them increasingly interlinked economically. And by the 1980s political engagement was also rising. This was highlighted in 1984, when the South Korean president, Chun Doo Hwan, became the first Korean leader to visit Japan since 1945—a visit that saw the Japanese Emperor, Hirohito, express regret over the “unfortunate past” between the two countries.
But while this was undoubtedly a significant step forward, it wasn’t enough for many in South Korea, who wanted nothing less than a formal apology for what had happened. On top of this, the relationship was also soured by several other issues. These included persistent claims of racism against the Korean community in Japan and tensions over the ownership of a small group of islands.
Meanwhile, by the start of the 1990s the horrific abuse suffered by the Comfort women began to gain greater prominence. This came to International attention in 1993, when Japan formally apologised to the victims, later setting up a fund to help survivors across the Philippines, Indonesia, Taiwan, and South Korea.
Progress and Setbacks in Bilateral Japan-South Korea Relations
But the really big step forward came in October 1998, when the Japanese prime minister hosted the South Korean president for talks in Tokyo. As well as announcing a new partnership between the countries, the Japanese leader issued a landmark statement of regret for the damage inflicted on Korea during Japanese colonial rule.
After this, it was hoped that this would finally mark a new chapter in relations. And over the next decade, the two countries did in fact appear to be moving in a new direction with regular high-level meetings between the leaders.
However, this all came crashing down in 2012 and 2013. By this point, the issue of the comfort women had become what the South Korean president called the “biggest obstacle” to improved ties. Despite the earlier Japanese compensation payments to victims across Asia, South Korea now wanted a specific package for its own citizens. Having failed to make progress on the matter at their summit in 2011, the South Korean president enraged Japan by becoming the first serving Korean head of state to visit the disputed islets—a move that prompted Japan to recall its ambassador to Seoul.
But the most significant blow came in 2013 when the Japanese prime minister, Shinzo Abe, paid a high-profile visit to a shrine honoring Japan’s War dead, including convicted war criminals. The decision was not only strongly condemned by both South Korea and China, angry at what they viewed as a direct provocation, but even the United States also expressed disappointment at a move that it felt would exacerbate tensions.
Relations Between Seoul and Tokyo, 2015-2023
Despite all this, by 2015 things seem to be improving again. The breakthrough came when the sides agreed that Japan would pay a billion yen, around $8 million, into a South Korean fund to compensate the last few surviving comfort women.
This was again hailed as an important step forward, especially as the two countries insisted that the matter had now been resolved “finally and irreversibly.” Indeed, the deal was widely welcomed internationally, including by the UN Secretary-General Ban Ki Moon, the former South Korean foreign minister.
But, yet again, progress was short-lived and by 2018 relations were crumbling once more. With Seoul accused Abe of failing to send a letter of apology to the surviving comfort women, Tokyo was furious when the new South Korean government, which had opposed the original settlement, backed away from the deal and dissolved the compensation fund. In addition, relations suffered yet another huge blow when the South Korean Supreme Court ruled that Japan must compensate workers used as slave labor during the occupation.
Rejecting the decision, in 2019 Japan took South Korea off its list of preferential trade partners, thereby sparking a trade war. As a result of all this, many observers now argued that bilateral ties between Tokyo and Seoul had reached the lowest point since they’d established diplomatic relations in 1965.
The Yoon-Kishida Summit, March 2023
So, what lies behind the current rapprochement? There are in fact two key factors. The first centers on broader regional security concerns. As well as fears about China’s growing strength,
both countries are increasingly nervous about North Korea. In 2022, Pyongyang dramatically accelerated its ballistic missile program, firing long-range missiles over Japan for the first time in several years. All this has seen Japan and South Korea step up their close cooperation with the United States and with each other. As well as more high-profile diplomatic meetings, the three countries have also staged joint military exercises.
Secondly, and crucially, it rests on political changes in South Korea. In 2022, the country elected a new president, Yoon Suk Yeol, a former prosecutor on the political right. He has called for a more uncompromising stand against North Korea and for closer ties to Japan. This all came together at the end of February 2023 when South Korea dropped the call for Japan to compensate the slave workers, a move that in turn saw Japan announced the easing of trade restrictions and paved the way for the first high-level summit in 12 years. Held in Tokyo, the atmosphere was certainly warm.
With the Japanese prime minister insisting that the talks opened a new chapter in relations, the leaders agreed to resume regular high-level meetings and announced that they would introduce a number of measures on a case-by-case basis. It was also warmly welcomed by many of the two countries closest partners, not least of all the United States which had push for the meeting.
All this has prompted optimism that a new security relationship might now be created. And there’s even been talk that an invitation could be extended to South Korea to join the Quad—an emerging security partnership involving Australia, the United States, Japan, and India—that aims to contain growing Chinese influence in the Indo-Pacific region.
But as hopeful as things seem, many nevertheless urge caution. After all, the history of relations between Japan and South Korea has been littered with breakthroughs that have ultimately failed. While some worry that a future South Korean government could again jeopardize progress by rescinding any agreements, others insist that Japan still hasn’t truly come to terms with its role in Korea. Meanwhile, in a broader sense, the situation highlights how countries that are essentially close allies can nevertheless have a complex and strained bilateral relationship, despite sharing so many close economic, political and security interests.
James Ker-Lindsay is a research associate at the European Institute, London School of Economics, and a visiting professor at the University of Kent. His YouTube Channel can be found here.