Japan and South Korea Deepen Military Cooperation Amid Shared Security Threats
Primary region Asia
Tags Diplomacy · Security · Policy
Regions Asia
Japan and South Korea are institutionalizing defense cooperation through planned 2+2 ministerial meetings and a Japan defense chief visit to Seoul in June, driven by shared concerns over China, North Korea, and US alliance uncertainty under the Trump administration. In January 2026, Japan's Air Self-Defense Force provided midair refueling support to a South Korean aircraft, marking operational-level military collaboration. Prime Minister Takaichi Sanae and President Lee Jae-myung have held two summits with a conciliatory tone, defying expectations given their ideological differences.
Strategic interpretation
The Japan-South Korea rapprochement is one of the most significant strategic developments in the Indo-Pacific, driven less by bilateral reconciliation than by shared anxiety about US alliance reliability under Trump. The operational-level military cooperation (midair refueling) represents a concrete step toward interoperability that would have been unthinkable five years ago. However, the partnership remains fragile — domestic political shifts in either country, or a US-Korea trade dispute, could reverse progress. China's opposition to closer US-allied military cooperation in the region adds urgency to the arrangement.