By Zarak Khan | 2025-11-24

Japan and Indonesia are intensifying their defense and maritime cooperation, reaffirming their efforts to align positions on developments in the East and South China seas, a shift widely viewed as part of a broader strategy to counter China's expanding regional influence.

At their third "two-plus-two" Foreign and Defense Ministerial Meeting in Tokyo on Nov. 17, Indonesian Defense Minister Sjafrie Sjamsoeddin and Foreign Minister Sugiono discussed Indonesian-Japanese security ties with Japanese Defense Minister Shinjiro Koizumi and Foreign Minister Motegi Toshimitsu, according to Japan's Foreign Ministry. Other topics included regional tensions and broader international cooperation.

The two countries agreed to "strengthen efforts toward the realization of a 'Free and Open Indo-Pacific (FOIP),'" emphasizing that enhanced security cooperation between Japan and Indonesia, both democratic and maritime nations, is of strategic significance.

Japan and Indonesia elevated their relationship to a comprehensive strategic partnership in 2023. They committed to pursue synergies between the FOIP vision and the ASEAN Outlook on the Indo-Pacific, a framework adopted by ASEAN leaders to guide the region's engagement based on openness, inclusivity and cooperative principles.

Countering Beijing's maritime moves

Territorial tensions in the contested South China Sea are driving the need for enhanced maritime security cooperation between Jakarta and Tokyo.

China claims more than 80% of that sea as its territory, even though an international court rejected that assertion in 2016.

At the same time, Japan is embroiled in a fierce diplomatic dispute with China, particularly following Prime Minister Sanae Takaichi's recent remarks suggesting that Japan could consider military options if a conflict over Taiwan breaks out.

Indonesia faces its own worsening friction with Beijing, as its Exclusive Economic Zone overlaps significantly with China's claim over almost all of the South China Sea.

During their November 17 meeting, ministers from both Indonesia and Japan expressed "serious concern against the continuation and the intensification of the unilateral attempts to change the status quo by force or coercion" in the East and South China seas, Japan's Foreign Ministry said.

They further underscored the need for adhering to international law, especially the United Nations Convention on the Law of the Sea, to maintain a rules-based maritime order.

Defense deals and tech sharing

Japan views Indonesia as a critical partner in strengthening regional maritime defense and has intensified efforts to promote defense equipment and technology cooperation with Jakarta.

During his visit, Sjafrie toured the Yokosuka naval base, where he inspected several Japan Maritime Self-Defense Force vessels, including the Mogami-class Kumano frigate, a Murasame-class destroyer and a Taigei-class submarine.

Japanese officials provided a detailed briefing on the Kumano's capabilities, reflecting Tokyo's interest in promoting defense exports to Indonesia, a growing market.

This visit follows the launch of a Japanese-Indonesian defense consultation mechanism in January. It was aimed at solidifying cooperation on maritime security, defense equipment and technology transfer.

Negotiations are under way on joint development and production of advanced frigates for the Indonesian navy.

Indonesia has expressed a strong interest in Japan's upgraded Mogami-class frigates, which Japan will also export to Australia.

Tokyo has reportedly proposed a $1.94 billion package for the initiative, which would include constructing four frigates in Japan and four additional vessels at Indonesia's state-owned shipyard PT PAL, according to the Japan Times.

Indonesia is simultaneously advancing its broader military modernization program.

It is moving forward with its $8.1 billion purchase of 42 Rafale fighter jets from France, with the first deliveries expected in early 2026.

Growing military interoperability

Beyond their alignment, Indonesia and Japan have expanded joint exercises and strengthened interoperability with key partners, particularly the United States.

Held in August near Jakarta, the most recent Super Garuda Shield exercises brought together more than 6,000 troops from Indonesia, Japan, the United States, Australia, Canada, the United Kingdom, Brazil, South Korea, the Netherlands, New Zealand, Singapore, Germany and France.

The drills ensure that, "as a team of nations, we can meet regional challenges and keep the Indo-Pacific free and open," US Indo-Pacific Command chief Adm. Samuel J. Paparo said at the opening ceremony in Jakarta.

Japan, the Philippines and the United States conducted joint maritime drills in the South China Sea from November 14 to 15, underscoring expanding security coordination among partners as China deployed a bomber formation for what it called "routine patrol operations" during the same period.

Indonesia has additionally agreed to sign a new security treaty with Australia, outlining plans for closer strategic cooperation in the contested Asia-Pacific region.