A New Phase in Japan's Defense Diplomacy: Strengthening Cooperation with Pacific Island Nations and Deepening India-Japan Defense Cooperation

On February 24, 2026, Japan's defense diplomacy entered a new phase. Defense Minister Shinjiro Koizumi announced at the 3rd Japan-Pacific Island Defense Dialogue held in Tokyo that Japan would begin accepting young and mid-level defense personnel from Pacific island nations starting in the 2026 fiscal year. At the same time, the 7th joint military exercise "Dharma Guardian 2026" between India and Japan commenced in Uttarakhand, indicating the multilayered development of Japan's defense partnership strategy.

The defense dialogue included defense ministers from 14 Pacific island nations, including Fiji and Papua New Guinea, and for the first time, seven ASEAN countries participated as observers. The participating countries included Indonesia, the Philippines, Malaysia, Vietnam, Singapore, Thailand, and Brunei, demonstrating that Japan's vision of a "Free and Open Indo-Pacific" is evolving into a new security network connecting Pacific island nations and Southeast Asian countries.

In his speech, Minister Koizumi emphasized the need for cooperation in a wide range of areas, including strengthening cybersecurity, in light of China's increasing presence in the South Pacific. The Japanese government is working to strengthen relations with island nations in collaboration with the United States and Australia, and has agreed to provide drones to the Tonga military and heavy machinery to the Papua New Guinea military in the 2026 fiscal year. Additionally, Japan has dispatched Self-Defense Force personnel to Fiji to support capacity building in disaster relief and health sectors.

The South Pacific region, where the Pacific island nations are located, is a strategic sea lane for transporting mineral resources and food from Australia to Japan and the United States, and it has a vast exclusive economic zone rich in marine resources such as tuna and bonito. Traditionally, this region has had strong ties with Australia and New Zealand, but in recent years, China has gained significant influence through large-scale loans for infrastructure development, intensifying geopolitical competition.

China aims to establish bases that enable military activities beyond the "Second Island Chain," which stretches from Japan's Izu Islands to Guam and Papua New Guinea. In 2022, it was reported that China and the Solomon Islands signed a security agreement, allowing the deployment of Chinese military forces to the Solomon Islands. This move could have a direct impact on Japan's security environment.

Meanwhile, the India-Japan joint military exercise "Dharma Guardian 2026," which began today, will be conducted in Chaubattia, Uttarakhand, from February 24 to March 9, 2026. This seventh iteration of the exercise aims to enhance interoperability in urban combat and counter-terrorism operations, marking an important development following the previous 2025 edition, which was expanded to a battalion scale at Japan's Higashi-Fuji training area.

Key activities of the exercise include the establishment of a temporary operational base, deployment of an intelligence, surveillance, and reconnaissance (ISR) grid, operation of mobile checkpoints, encirclement search operations, helicopter-borne operations, and building entry training. The Indian Army stated, "Dharma Guardian 2026 reaffirms our common commitment to the growing India-Japan defense partnership and regional security."

Japan and India's defense cooperation is expanding beyond military exercises. In January 2026, Foreign Minister S. Jaishankar and Foreign Minister Toshimitsu Motegi launched a new AI dialogue during the 18th Strategic Dialogue and decided to hold a joint working group on critical minerals. This is an important indicator of the expanding scope of bilateral cooperation.

This series of movements in Japan's defense diplomacy holds several strategic significances. First, Japan is building a multilateral security network with India, Australia, Pacific island nations, and ASEAN countries while maintaining its alliance with the United States as the cornerstone. This aims to create a more resilient security posture that does not rely solely on a single alliance.

Second, Japan's approach to defense cooperation is evolving from traditional bilateral exercises to the construction of a regional security architecture. By inviting Pacific island nations and ASEAN countries to the same forum and discussing cooperation in a wide range of areas such as cybersecurity, climate change, and humanitarian assistance/disaster relief, Japan is attempting to form a comprehensive regional security framework.

Third, Japan's emphasis on "capacity building support" is noteworthy. By not only providing defense equipment but also supporting technology transfer and training through the dispatch of Self-Defense Force personnel, Japan is helping partner countries enhance their autonomous defense capabilities. This will serve as a foundation for building long-term trust and sustainable security cooperation.

As China's military power and influence expand, Japan's defense diplomacy is evolving beyond a simplistic "containment of China" framework to a more sophisticated, multilayered approach. Strengthening cooperation with Pacific island nations and India aims not only to counter China but also to build a framework for jointly addressing diverse security challenges faced by the region, such as climate change, marine resource management, and disaster response.

Looking ahead, Japan plans to invite young and mid-level officials from three countries, including Fiji, through the program for accepting defense personnel from Pacific island nations starting in the 2026 fiscal year, conducting about a week of exchanges and unit visits. Such human exchanges are crucial for building long-term trust and will serve as a foundation for further deepening defense cooperation between the two countries in the future.

Moreover, the expansion of the "Dharma Guardian" exercise to battalion scale and its evolution into more practical training content indicate that defense cooperation between the two countries is transitioning from a formal nature to a substantial enhancement of interoperability. In the future, cooperation in maritime security, space, and cyber domains between Japan and India is also expected to expand.

Japan's defense diplomacy is shifting from a traditional passive stance to an active role in shaping the regional security architecture. Strengthening relations with Pacific island nations, deepening defense cooperation with India, and expanding collaboration with ASEAN countries are all concrete actions Japan is taking to realize a "Free and Open Indo-Pacific." The simultaneous developments on February 24, 2026, will be recorded as a historic turning point symbolizing that Japan's defense diplomacy has entered a new phase.