Japan-South Korea relations reach new high under conservative-liberal 'odd couple' diplomacy
Primary region Asia
Tags Diplomacy · Security
Regions Asia · US

Japan's conservative Prime Minister Takaichi Sanae and South Korea's liberal President Lee Jae-myung have held two summits in 2026, defying historical expectations that a conservative-liberal ideological pairing would worsen relations. The two leaders agreed to enhance cooperation in economic security, defense, and searching for remains of Korean forced laborers. Analysts cite shared concerns over an assertive China, North Korea's weapons program, and unpredictable US commitments under President Trump as the driving force. Both leaders separately engaged with China: Lee met President Xi in Beijing, and Takaichi discussed regional issues including China with Lee. The Diplomat describes this as the closest Japan-South Korea relations have been in over 70 years.
Strategic interpretation
The thaw in Japan-South Korea relations is driven less by reconciliation on historical grievances and more by shared strategic anxiety about China, North Korea, and the reliability of US security guarantees. This makes the rapprochement potentially durable (threat perceptions are structural) but also fragile (it depends on continued alignment of threat assessments). Both leaders maintain parallel relationships with Beijing, suggesting neither wants full containment economics. For the US, closer Japan-South Korea cooperation reduces the burden of bilateral alliance management but also complicates Trump's transactional approach to alliances, which works better when partners are divided.