Triangle of opportunity: How improved relations between South Korea and Japan open doors for the EU

Japan’s new prime minister Ishiba Shigeru, who took office in early October, has inherited unusually positive relations with South Korea. Known for his defence expertise, Ishiba has signalled his intent to maintain many of the policies of his predecessor Kishida Fumio in improving relations with Seoul, particularly in the security realm, both bilaterally and through cooperation with the United States.

This is good news for the EU, which grapples with many of the same challenges as its East Asian partners – such as North Korea’s growing belligerence, its supporting role in Russia’s war in Ukraine, and economic and security threats from China. A stable relationship between South Korea and Japan aligns with the EU’s core interests as it facilitates collective responses to these issues. Brussels now has the chance to actively enhance these ties by elevating key aspects of its bilateral relations with South Korea and Japan to a trilateral level.

The historically strained ties between Japan and South Korea has made their rapprochement fragile from the beginning; domestic politics still pose a threat to the reconciliation process, and the EU should be mindful of these sensitivities. But a worsening external environment has strengthened the strategic rationale for Japan and South Korea’s cooperation. One significant development is North Korea’s escalating security threat. In January 2024, leader Kim Jong Un abandoned the long-standing official goal of reunification and announced plans to declare South Korea a “principal enemy” in the North’s constitution, noting the possibility of “recapturing” or “incorporating” the South into the its territory.

Meanwhile, Pyongyang is also strengthening ties with Russia. Recent Ukrainian and South Korean intelligence reports claim that North Korea is deploying soldiers to assist Russia in its war in Ukraine. These reports come in the wake of the June summit between Kim and Russian president Vladimir Putin, in which they signed a “comprehensive strategic partnership”, raising alarms that Russia may provide crucial technology to advance North Korea’s nuclear weapons programme in exchange for arms and ammunitions. These developments are a stark reminder of the increasingly intertwined security concerns facing both Europe and Northeast Asia.

The wider regional situation also remains tense, with China ramping up pressure in the South China Sea, including 12 incidents of “unsafe behavior” with Philippine vessels since early 2023. Tensions over Taiwan are also increasing, with Beijing fully encircling the island in a recent large-scale military exercise; a trilateral summit between Beijing, Seoul, and Tokyo in May produced limited outcomes, highlighting Japan and South Korea’s reluctance to fully engage with China, especially on economic security matters.

Amid this deteriorating external environment, a bold diplomatic overture from South Korea to Japan in the spring of 2023 set both countries on a clear rapprochement path. In an effort to improve relations with its neighbour, President Yoon Suk-yeol proposed a plan to compensate Korean victims of forced labour by Japanese companies during World War II using exclusively local funds. This move prompted the resumption of shuttle diplomacy and regular high-level meetings between both nations, resulting in key diplomatic, economic, and security agreements.

They normalized military relations in June this year at the Shangri-La Dialogue, moving past a 2018 incident in which a Korean warship locked its targeting radar onto a Japanese military surveillance plane. Economic relations are also improving quickly, with a joint economic task force addressing supply chain vulnerabilities and collaboration in semiconductors and green energy, particularly hydrogen. In July, South Korea approved a Japanese gold mine for UNESCO World Heritage status after Japan agreed to acknowledge and commemorate Korean forced labour at the site during World War II. This newfound trust could allow the two governments to better handle events that, in the past, have led to diplomatic spats, such as a Japan’s demand to a Korean company to divest from a joint venture in Japan after a cybersecurity incident.

US leadership and trilateral cooperation have been key in this improvement as well. The August 2023 summit at Camp David was a key milestone as it established a security framework with joint military exercises and intelligence sharing to counter threats from North Korea and China. The three nations also launched the Trilateral Economic Security Partnership, focusing on supply chain resilience in semiconductors and clean energy, alongside a cybersecurity pact and a coordinated climate change strategy.

Camp David also led to enhanced military cooperation. This July, the three countries signed the Memorandum of Cooperation of the Trilateral Security Cooperation Framework (TSCF), cementing defence ties and ensuring they are less easily reversible. Effective immediately, the agreement institutionalizes trilateral defence engagement, including senior-level policy consultations, information sharing, exercises, and defence exchange cooperation.

But the thaw contrasts sharply with the fierce domestic backlash in South Korea against the gold mine decision, and the narrow avoidance of an ultranationalist prime minister in Japan’s recent LDP leadership elections. Moreover, the upcoming US presidential election raises doubts over Washington’s commitment in maintaining the same level of support for the cooperation process.

For the first time since the end of the Korean War, there is political space to propose trilateral initiatives with Seoul and Tokyo

These developments only underscore the importance of the EU strengthening its relations with Japan and South Korea. While the EU cannot, should not, and will not replicate the role of the US for its two East Asian partners, for the first time since the end of the Korean War there is political space to propose trilateral initiatives with Seoul and Tokyo.

The EU can count on a rich policy foundation on which to build this cooperation. It already boasts several bilateral initiatives with Japan and South Korea that are potentially complementary. For instance, the EU could propose merging its existing trade agreements with both countries into a single trilateral framework, which would create one of the world’s most powerful trade blocs. Similarly, the EU’s separate Digital Partnership Agreements with Japan and South Korea could be expanded into a trilateral format, focusing on joint initiatives that leverage the digital strengths of all three. Such an approach would make it easier to establish unified standards for data governance, cybersecurity, and emerging technologies like AI and 5G, ensuring interoperability and bolstering digital security across the EU, Japan, and South Korea.

There is also potential for joint research and development in areas like quantum computing, blockchain, and smart cities, supported by the EU’s Horizon Europe programme. Emphasizing the creation of resilient supply chains for digital technologies and semiconductors could also strengthen all three economies against global disruptions. In terms of security, the EU could help establish a trilateral cybersecurity task force that would enhance information sharing, conduct joint exercises, and build capacities. The EU should also keep supporting Japan and South Korea’s engagement and coordination with NATO’s global strategy.

All of this is, of course, very ambitious. At every step of the way, it is imperative for EU policymakers to stay humble and attentive to the delicate balance of the South Korean-Japanese relationship. However, the potential benefits of joint collaboration with Seoul and Tokyo are too significant to be ignored. Brussels could begin by proposing a trilateral EU-Japan-South Korea summit to gauge interest and explore initial ideas for cooperation. The worst outcome at this point is a rejection, but Tokyo and Seoul might well be receptive to such overtures. The resulting cooperation not only promises to boost regional stability in East Asia, but will also bolster the EU’s own security and alliances in the face of shared global challenges.