Indonesia and Japan Sign Defense Cooperation Agreement, With Japan Offering Frigates and Submarines
Primary region Asia
Tags Security · Diplomacy
Regions Asia

Indonesian Defense Minister Sjafrie Sjamsoeddin and Japanese Defense Minister Shinjiro Koizumi met in Jakarta on May 4, 2026, signing a Defense Cooperation Agreement covering defense-industry cooperation, personnel exchanges, joint exercises, maritime security, and humanitarian relief. Japan offered Indonesia Mogami-class frigates and Soryu-class submarines, with the Indonesian Navy confirming the offer is under consideration. The agreement follows PM Takaichi's April 2026 lifting of lethal arms export restrictions. Japan signed a $7 billion deal with Australia on April 19 for 11 upgraded Mogami-class frigates. Both countries share concern over the South China Sea as a crucial maritime corridor.
Strategic interpretation
The Indonesia-Japan defense agreement is a significant step in building Southeast Asian maritime capacity as a counterbalance to China's South China Sea assertiveness. For Japan, Indonesia represents a strategically vital partner controlling key sea lanes. The frigate and submarine offer, if accepted, would be one of Japan's largest arms exports and could reshape the regional naval balance. The deal also signals that Japan's new arms export policy is moving from policy to practice.