India-Japan Defence Cooperation Expands From Maritime Security to Advanced Military Technology
India and Japan are taking defence cooperation into a new phase, expanding beyond exercises into naval shipbuilding, submarine technology, marine and aero engines, amphibious aircraft, military-grade semiconductors, UNICORN, unmanned systems, AI, electronic warfare and secure communications. The new maritime security arrangement strengthens operational coordination, logistics and information sharing, while Japan’s revised defence export rules could unlock deeper technology transfer and joint development opportunities for India.
DEFENCE NEWS
India and Japan are moving into a broader phase of defence cooperation, with the relationship expanding beyond military exercises towards technology transfer, joint development, shipbuilding and defence-industrial cooperation.
The shift was evident during Defence Minister Rajnath Singh's meeting with Japanese Defence Minister Shinjiro Koizumi in New Delhi on August 20. The two sides signed a Memorandum of Arrangement (MoA) on Maritime Security Cooperation while also identifying a wider set of areas for collaboration, including naval shipbuilding, conventional submarines, marine engines, amphibious aircraft, aero-engine technology, advanced electronics, unmanned systems and electronic warfare.
Japan's revision of its defence equipment and technology transfer framework in April has made this expansion considerably more feasible.
Naval Shipbuilding and Submarine Technology
India and Japan will explore joint development in naval shipbuilding and design, combining Japanese technological expertise with India's growing production capabilities. The two sides will also examine greater use of Indian shipbuilding capacity under the Make in India framework and work towards reciprocal access to ship repair and maintenance facilities.
For India, Japanese expertise in naval architecture, systems integration and advanced maritime engineering could complement its expanding domestic shipbuilding ecosystem. Conventional submarine technology is another potential area of cooperation, particularly given Japan's experience with advanced conventionally powered submarines and battery technologies.
Marine Engines and Aero-Engine Technology
Propulsion is another area where Japanese expertise could complement India's requirements. India is seeking to strengthen domestic capabilities in marine engines and associated technologies as its naval fleet expands.
Aero-engine technology is also among the broader areas of interest. While no specific engine programme has been announced, cooperation with Japanese industry could potentially contribute to India's efforts to develop critical propulsion technologies and reduce dependence on foreign sources.
US-2 Amphibious Aircraft
Japan's ShinMaywa US-2 remains a prominent potential area of defence cooperation. In January, India's Ministry of Defence sought prospective lessors for four amphibious aircraft for four years, with the US-2 among the aircraft being considered.
The aircraft could support long-range search and rescue, casualty evacuation, special operations, humanitarian assistance and logistics, particularly across the Andaman and Nicobar Islands and Lakshadweep. India had previously explored local production of the US-2, but that proposal did not progress.
Semiconductors and Advanced Electronics
Japan's expertise in advanced electronics and semiconductor technologies could support India's growing demand for critical components used in military systems.
Military-grade processors, sensors, RF components and secure electronics are increasingly important for fighters, warships, missiles and unmanned platforms. Cooperation in this field could complement India's efforts to build a more resilient domestic defence-electronics ecosystem.
UNICORN: The First Defence Equipment Project
The Unified Complex Radio Antenna (UNICORN) is already providing a practical foundation for India-Japan defence-industrial cooperation.
India and Japan signed their first defence equipment co-development and co-production agreement for the shipborne system in 2024. UNICORN integrates multiple communications functions into a single antenna architecture and is used on Japanese warships. Both sides have now reaffirmed their commitment to its early realisation.
The project is significant because it establishes a model based on Japanese technology combined with Indian industrial participation rather than simple equipment procurement.
Unmanned Systems, AI and Electronic Warfare
The technology partnership is also moving into emerging warfare domains. India and Japan will integrate unmanned systems into bilateral exercises and explore short-notice joint exercises.
Cooperation between India's DRDO and Japan's Acquisition, Technology & Logistics Agency (ATLA) will also expand in advanced defence technologies. Potential areas include artificial intelligence, counter-UAS systems, electronic warfare, RF technologies and secure communications—capabilities that are increasingly central to modern networked and electromagnetic warfare.
Maritime Domain Awareness and Logistics
The new maritime security arrangement provides the operational framework for closer cooperation between the Indian Navy and Japan Maritime Self-Defense Force.
The two sides will strengthen Maritime Domain Awareness, information sharing, search and rescue, humanitarian assistance and disaster relief, while increasing reciprocal naval visits, personnel exchanges and subject-matter expert interactions.
They will also explore greater access to ports and maintenance facilities and work towards reciprocal ship-repair arrangements. Such cooperation can improve the ability of both navies to sustain deployments across the Indo-Pacific.
Mine Countermeasures and Special Operations
India and Japan will increase cooperation in mine countermeasures, an area in which Japan has considerable operational experience. The capability is particularly relevant to protecting ports, chokepoints and maritime approaches during a conflict.
The two sides will also expand exchanges between their Special Operations Forces and pursue cooperation with India's integrated theatre commands following their establishment.
More Complex Military Exercises
India and Japan already conduct JAIMEX, Dharma Guardian and Veer Guardian. The next stage will involve more complex and operationally demanding exercises.
Japanese fighter aircraft will participate in Veer Guardian 26 in India for the first time. Both sides also plan to incorporate unmanned systems and explore short-notice exercises, improving interoperability and the ability to respond together to emerging contingencies.
The Indo-Pacific Context
The defence relationship is developing against a backdrop of increasing strategic competition in the Indo-Pacific. India and Japan have expressed opposition to unilateral actions that impede freedom and safety of navigation and overflight or seek to alter the status quo through force or coercion.
Although China was not directly named, the position reflects concerns over its expanding military presence in the East and South China Seas and growing activities across the Indian Ocean. India and Japan are also members of the Quad alongside the United States and Australia.
The two countries will establish a working group at the Director-General/Joint Secretary level covering operational, intelligence, equipment, technology and industrial cooperation. They will also accelerate preparations for the fourth India-Japan 2+2 Foreign and Defence Ministerial Dialogue in Tokyo.
The significance of the latest engagement is therefore broader than the maritime security agreement itself. India and Japan are building a defence relationship around technology, shipbuilding, industrial production and operational interoperability.
The immediate challenge is converting these areas of cooperation into concrete joint programmes and technology transfers. If that happens, Japan could become an increasingly important partner in India's effort to build advanced maritime and defence capabilities domestically.