Shinjiro Koizumi’s Maiden India Visit: Making of a More Capable Indo-Pacific Partnership

Koizumi’s visit, following the July India–Japan summit, comes amid a broader expansion of defence, technology and industrial cooperation, giving the partnership a foundation that extends beyond military diplomacy. For India, closer maritime coordination strengthens its tactical options across critical sea lanes, while Japan gains a capable partner positioned at the heart of the wider Indo-Pacific.

For centuries, Asia’s great powers have understood the sea as both a connection and a shield. India and Japan are now rediscovering that old lesson with decidedly modern tools. The map may show borders, but the ocean shows dependencies, and nowhere are those dependencies more consequential than the Indo-Pacific.

Japanese Defence Minister Shinjiro Koizumi arrived in India on August 19 for his maiden official visit, and while the symbolism was important, the substance mattered more. The language was about both freedom and coercion. The geography supplied the footnotes.

His two-day engagement in Mumbai and New Delhi came as India and Japan sought to push their defence relationship beyond political convergence towards something harder to manufacture and far more valuable, like operational capability. Their challenge is no longer to agree that the Indo-Pacific should remain free and open. That goes without saying. The difficult task for the diplomats and experts in Tokyo and New Delhi is to build the habits and technologies that can actually keep the Indo-Pacific free.

A Sea of Opportunities

Japanese Defence Minister Shinjiro Koizumi

At Mumbai’s Western Naval Command, Koizumi inspected the Guard of Honour, laid a wreath at the Gaurav Stambh and received briefings on the Indian Navy’s operational responsibilities and regional commitments. His visit to INS Chennai, India’s indigenously built guided-missile destroyer, brought the conversation closer to the machinery of maritime power. He also met Chief of the Naval Staff Admiral Krishna Swaminathan and Vice Admiral Sanjay Mahajan Vatsayan, Flag Officer Commanding-in-Chief, Western Naval Command.

It is widely known that naval partnerships are built through familiarity, and familiarity comes from ships, officers, exercises and institutions repeatedly working alongside one another. Japanese Ambassador to India Keiichi Ono described the Mumbai discussions as “fruitful” and welcomed efforts to advance maritime cooperation.

The next day in New Delhi, Koizumi met Defence Minister Rajnath Singh, where the relationship moved from the deck of a warship to the highest table in the domain. India and Japan signed a maritime security cooperation arrangement focused on deeper naval coordination, information sharing and practical cooperation across the Indo-Pacific.

The Ocean Has a Lasting Memory

The India–Japan maritime relationship did not begin with destroyers. It has roots in very humane interventions. On December 26, 2004, the Indian Ocean tsunami shattered coastlines across the region. India launched a massive military relief operation and sent ships, aircraft and medical teams to Sri Lanka, the Maldives and Indonesia. The Indian Navy’s Operation Rainbow sent seven ships, including a specialist hospital ship, to Sri Lanka. Japan, meanwhile, mobilised major humanitarian assistance and deployed a maritime unit for search-and-rescue operations around Thailand.

The lesson was difficult but enduring, because it proved that maritime power was not merely about preparing for war, but also about reaching out to people in times of despair. Today, cooperation between India and Japan includes search and rescue, humanitarian assistance and disaster relief, areas where trust between institutions can save lives long before it becomes relevant to deterrence. Their Coast Guard relationship, formalised through a 2006 memorandum, has developed through regular exercises and operational exchanges focused on search and rescue, pollution response and maritime law enforcement.

Before warships became the more visible symbol of cooperation, the relationship was strengthened by what might be called the “white ships” of maritime security.

Decoding the Diplomatic Language

The most revealing part of the discussions may be what India and Japan chose not to say. Neither side needed to turn the meeting into an explicit anti-China declaration. Their emphasis on freedom of navigation, overflight, maritime security and opposition to attempts to change the status quo through force or coercion already carries strategic meaning in a region where competition is intensifying. 

Such calibrated language matters because neither India nor Japan needs a formal alliance to deepen their coordination. What they require is the ability to act together when their interests converge, particularly across the maritime spaces on which their economies and security depend.

As Dr Gitanjali Sinha Roy,, Assistant Professor of International Relations, Indo-Pacific Studies and Japanese Studies at the Jindal School of International Affairs, O.P. Jindal Global University, observes:

“India and Japan have worked on maritime relations in order to keep their interests in the sea lanes of communication, freedom of navigation and overflight in the Indo-Pacific. In the recent Defence Ministers' meeting between India and Japan emphasised on deeper and deeper defence cooperation, which would pave the way for peace, stability and prosperity in the Indo-Pacific region. Both countries, without mentioning China, they highlighted the efforts that were made to change the status quo by force or by the use of coercion.

Furthermore, maritime cooperation was one of the key cornerstones of this meeting, where they looked at more meaningful operational cooperation in maritime security, which needed to be dealt with greater practicality, while also looking at effective means of information sharing for maritime domain awareness, search and rescue, humanitarian aid, assistance and disaster management. Emphasis on the need for mutual visits of naval ships and units, joint exercises, and a greater focus on subject-matter expert exchanges is new, along with a focus on the use of ports, maintenance and repair facilities, logistics, short-notice joint exercises, and unmanned systems working together. They also aimed at anti-mine capabilities and the setting up of a Defence Industry Forum, which were newer developments. Defence shipbuilding is picking up, along with ship-repair management, even more in recent times.”

Her assessment gets to the heart of what makes the latest engagement significant, as the relationship moves beyond broad strategic vocabulary towards the less glamorous but far more consequential machinery of maritime cooperation, encompassing information systems, ports, maintenance and logistics, expert exchanges and the ability to conduct exercises at short notice, This is eventually where trust begins to acquire operational meaning, because while friendship between governments may produce statements, a functioning maritime partnership will produce capabilities.

From Warships to Workshops

India and Japan are exploring cooperation in varied fields like defence shipbuilding, ship-repair management, mine-countermeasure capabilities, unmanned systems and related technologies. Discussions around a Defence Industry Forum could also provide a more permanent channel for industrial engagement. The proposed cooperation in naval design and manufacturing is particularly significant because it moves the relationship closer to the foundations of maritime power.

A navy cannot remain effective simply because its ships are technologically advanced. Ships need repair yards, spare parts, trained personnel, secure logistics and an industrial ecosystem capable of sustaining them when the strategic environment becomes difficult.

This is where Japan’s April 2026 revision of its Three Principles on Transfer of Defence Equipment and Technology becomes relevant. Tokyo has explicitly sought to make defence-equipment transfers a more useful instrument for regional security while retaining controls over their use and onward transfer.

The timing is significant for India as during the July 13 Japan–India Defence Policy Dialogue, Japanese Vice Minister of Defence for International Affairs Kano and Defence Secretary Rajesh Kumar Singh discussed implementation of the leaders’ summit outcomes, including defence equipment and technology cooperation. Japan also expressed its expectation that the transfer of the UNICORN system would advance steadily and that further areas of cooperation would be identified.

This is where trust begins to acquire physical form and becomes a radar system, a repair facility, a shipyard capability or an unmanned platform that two partners can depend upon.

The Sea Will Test What Diplomacy Promises

Koizumi’s visit, following the July India–Japan summit, comes amid a broader expansion of defence, technology and industrial cooperation, giving the partnership a foundation that extends beyond military diplomacy. For India, closer maritime coordination strengthens its tactical options across critical sea lanes, while Japan gains a capable partner positioned at the heart of the wider Indo-Pacific.

As Dr Sinha Roy observes, the relationship is growing into a more practical one through maritime domain awareness, naval exchanges, joint exercises, logistics, maintenance facilities and cooperation on unmanned systems, suggesting that trust is gradually acquiring operational form.

The real question, therefore, is whether political promises can translate into capabilities when circumstances deteriorate. Can information move quickly enough, ships reach one another efficiently enough and industries work closely enough to make the partnership dependable when the Indo-Pacific becomes turbulent?

The sea will not read the bulletin, but it will test the capability behind it. In the years ahead, India–Japan ties will be measured less by the warmth of diplomatic statements than by what their institutions can actually do together, because the ocean does not reward declarations; it rewards readiness. Remaining underprepared is a luxury the Indo-Pacific can no longer afford.