Why Japan Is Expanding Defence Ties Beyond India

Japan is deepening its defence relationship with India while simultaneously expanding its economic, infrastructure and security engagement with countries around India -- particularly Bangladesh.

The result is an emerging Japanese conception of South Asia in which India remains the strategic anchor, but the geography surrounding India is becoming increasingly important, points out Varun Arya.

Japan is not moving away from India.

It is moving beyond an India-only conception of South Asia.

That distinction provides the most useful lens through which to understand Japanese Defence Minister Shinjiro Koizumi's visit to New Delhi on August 19-20.

Koizumi's visit comes after the eighth Japan-India Defence Policy Dialogue in Tokyo on July 13 and follows the July 2 summit between Prime Ministers Takaichi Sanae and Narendra Modi.

The summit produced separate outcome documents on economic security and artificial intelligence, while the subsequent defence dialogue focused on implementing the leaders' decisions, defence-equipment and technology cooperation, and wider bilateral and multilateral coordination.

Japan has also welcomed India's support for its revised defence-equipment transfer framework and is moving ahead with the transfer of the UNICORN naval communication system.

The immediate agenda of Koizumi's India visit will therefore be bilateral.

Its strategic significance, however, is regional.

Japan is deepening its defence relationship with India while simultaneously expanding its economic, infrastructure and security engagement with countries around India -- particularly Bangladesh.

The result is an emerging Japanese conception of South Asia in which India remains the strategic anchor, but the geography surrounding India is becoming increasingly important.

The emerging map is best understood not as a formal Japanese corridor, but as a network: Japan-India-North East India-Bangladesh-Bay of Bengal-Indian Ocean-ASEAN. That network is being constructed through different instruments: Defence cooperation, technology partnerships, infrastructure, economic integration, development assistance and maritime connectivity.

Koizumi's visit therefore offers a window into a larger transformation in Japanese strategy.

India Remains The Anchor

There is little doubt about India's centrality to Japan's regional strategy.

The relationship has moved far beyond the traditional language of strategic partnership.

Defence cooperation is increasingly being linked to technology, industrial capacity, inter-operability and economic security.

The July 2 summit demonstrated this widening agenda.

Japan and India issued outcome documents covering economic security and AI cooperation, while the broader relationship continues to expand across critical technologies, supply-chain resilience, energy and defence.

The July 13 Defence Policy Dialogue added an important operational dimension.

Japanese and Indian officials discussed bilateral and multilateral security cooperation, defence equipment and technology cooperation, and the implementation of decisions reached at the leaders' summit.

Tokyo also highlighted the importance of advancing the UNICORN project and identifying additional areas of defence-technology cooperation.

This is significant because Japan's own defence transformation is increasingly dependent on technological, industrial and international partnerships.

The 2026 Defense of Japan places greater emphasis on strengthening defence capabilities, technological foundations and cooperation with partners.

It reflects a security environment in which no country can protect its interests in isolation and in which defence technology, economic security and industrial capacity are becoming increasingly interconnected.

India fits naturally into this framework.

It combines a large defence-industrial base, growing technological capabilities, a substantial military, strategic depth in the Indian Ocean and a geographic position linking the Indo-Pacific with continental Asia.

The relationship is consequently moving from exercises and political dialogue towards long-term capability development.

But this is precisely why the geography beyond India matters.

The Geography Beyond India

If Japan were simply strengthening its relationship with India, Koizumi's visit could be understood entirely through a bilateral lens.

But Tokyo is simultaneously building relationships with India's neighbours.

Bangladesh is perhaps the clearest example.

For decades, Japan's relationship with Bangladesh was dominated by development assistance, infrastructure and economic cooperation.

That relationship has not disappeared.

Instead, it is acquiring a stronger strategic dimension.

On February 3, Japan and Bangladesh signed an agreement establishing a framework for the transfer of defence equipment and technology.

Three days later, on February 6, the two countries signed their Economic Partnership Agreement -- the first EPA between Bangladesh and Japan.

The sequencing is revealing.

Japan is advancing security cooperation and economic integration with Bangladesh simultaneously.

That does not constitute a Japanese pivot away from India.

It suggests something more interesting: Tokyo is building a wider regional network in which India remains the principal strategic node.

Bangladesh matters because of geography.

It sits at the northern edge of the Bay of Bengal, at the intersection of South and Southeast Asia and immediately adjacent to India's north east.

Its strategic importance therefore extends beyond the bilateral Japan-Bangladesh relationship.

Bangladesh is a connector.

The North East Is The Missing Link

This is where India's north east becomes central to the emerging Japanese strategic picture.

The north east has traditionally been approached primarily as a frontier and security region. That perception is gradually changing.

It is increasingly being viewed as a gateway linking India to Bangladesh and Southeast Asia.

Japanese development cooperation is contributing to that transformation.

JICA is financing major road and bridge projects in the north east, including the Dhubri-Phulbari bridge across the Brahmaputra and road corridors extending towards Meghalaya's border with Bangladesh.

JICA describes these projects explicitly in terms of improving connectivity, facilitating cross-border trade and strengthening links between the north east and neighbouring Bangladesh.

These are not military projects. Nor should they be described as components of a formally declared Japanese strategic corridor. Their significance is structural.

Infrastructure reduces physical distance. Reduced distance creates commercial connectivity.

Commercial connectivity can generate economic interdependence. And economic interdependence can eventually produce greater strategic resilience.

For India, this supports the Act East policy.

For Japan, it creates another layer connecting its partnership with India to its engagement with Bangladesh.

The resulting geography is increasingly difficult to ignore: North east India-Bangladesh-Bay of Bengal.

The Bay of Bengal Is Becoming The Organising geography

The deeper significance of this network lies in the Bay of Bengal.

For much of Japan's post-Cold War strategic thinking, maritime attention was concentrated more heavily on north east Asian waters, the East China Sea, the South China Sea and the wider Pacific.

The Bay of Bengal occupied a comparatively peripheral position.

That is changing.

The Bay connects South Asia with Southeast Asia and the wider Indian Ocean.

Bangladesh sits on its northern edge.

India's eastern seaboard and north east connect into this space, while Myanmar and ASEAN extend the geography further east.

For Japan, this is not simply a maritime-security question.

It is also about trade routes, supply chains, infrastructure resilience, energy security and economic diversification.

Japan's engagement with Bangladesh's Matarbari port and the broader Bay of Bengal Industrial Growth Belt illustrates this approach.

The principal character of these initiatives remains economic and developmental.

But infrastructure of this scale inevitably produces strategic effects.

A better-connected Bangladesh can become a stronger logistics and commercial hub.

A better-integrated north east can deepen India's economic relationship with Bangladesh.

More resilient maritime infrastructure can support regional trade.

And greater economic diversification can give smaller states more options in dealing with competing major powers.

None of this requires militarising the Bay of Bengal.

The strategic logic is subtler: connectivity can itself become an instrument of resilience.

Japan's 2026 defence strategy provides the larger framework This is where Japan's 2026 Defense of Japan becomes particularly important.

The significance of the document lies not only in specific capabilities or weapons systems.

It is also conceptual.

Japanese security thinking is increasingly networked.

The document places national security within a broader framework involving diplomacy, defence, economic security, technology, intelligence and defence-industrial capacity.

Defence-equipment and technology cooperation is presented as one instrument through which Japan can strengthen partners, deter unilateral changes to the status quo and contribute to a more favourable security environment.

This changes the way Japan's regional relationships should be interpreted.

Defence cooperation with India is no longer simply military diplomacy.

Economic engagement with Bangladesh is no longer simply development assistance.

Infrastructure is no longer merely infrastructure.

Technology cooperation is increasingly connected to economic security.

The boundaries between these areas are becoming less distinct.

That is the strategic context in which Koizumi's visit should be understood.

Bangladesh Is Not A Substitute For India

There is a temptation to interpret Japan's expanding engagement with Bangladesh as an attempt to hedge against India or create an alternative to New Delhi. That would be a mistake.

Bangladesh cannot replicate India's strategic role for Japan.

India possesses a combination of economic scale, military capability, technological capacity, geographic depth and political influence that makes it fundamentally different from any other South Asian partner.

Bangladesh serves a different purpose.

It provides geographical connectivity.

It opens South Asia towards Southeast Asia.

It offers access to the northern Bay of Bengal.

And it gives Japan another partner through which economic, infrastructure and maritime resilience can be strengthened.

The two relationships are therefore complementary rather than competitive.

That distinction is critical.

Japan does not need Bangladesh instead of India.

It needs Bangladesh alongside India.

India's relationship with Bangladesh is shaped by proximity.

Migration, water, trade, border management, connectivity, the north east and domestic political developments inside Bangladesh can all have immediate consequences for India.

The events surrounding Sheikh Hasina's August 5 address in New Delhi demonstrated precisely this problem.

Hasina, who has remained in India since leaving Bangladesh in August 2024, delivered a virtual address at an event organised by the Foreign Correspondents' Club of South Asia in New Delhi.

She called for the lifting of the ban on the Awami League and said she intended to return to Bangladesh in December.

Bangladesh's government condemned the event while India stressed that the programme was organised by a private media organisation and that the Indian government had no involvement in it.

The episode illustrates how difficult it is for India to separate its relationship with Bangladesh from Bangladesh's internal political dynamics.

Japan faces no equivalent structural constraint.

Tokyo does not share a border with Bangladesh.

It does not face the same migration pressures, water disputes, border-security concerns or immediate political spillovers.

Distance gives Japan flexibility.

Proximity gives India influence -- but also entanglement.

That does not make Japanese diplomacy inherently superior to Indian diplomacy. It makes the two fundamentally different.

For Tokyo, Bangladesh can be approached primarily through development, economic partnership, infrastructure, maritime connectivity and strategic diversification.

For New Delhi, all of those issues coexist with the immediate consequences of Bangladesh's domestic politics.

This difference is likely to become increasingly important as Japan expands its regional presence.

China is part of the equation -- but not the entire equation

China inevitably forms part of the strategic background.

Beijing's economic and infrastructure footprint across South Asia and the Indian Ocean has expanded substantially.

Japan is also increasingly concerned about China's military capabilities and the changing regional balance.

The 2026 Japanese defence document reflects those concerns.

But interpreting Japan's South Asia strategy purely as China containment would miss the larger picture.

Japan's comparative advantage lies elsewhere.

It can provide infrastructure financing, technology, industrial cooperation, capacity-building, economic partnerships and increasingly sophisticated defence cooperation.

For countries such as Bangladesh, this creates additional strategic options.

The objective does not necessarily have to be to push Bangladesh into an anti-China camp.

It can instead be to prevent excessive dependence on any single external power.

This distinction is important.

Strategic diversification is not the same as containment.

And a more economically resilient and strategically autonomous Bangladesh need not be detrimental to India.

It could, under the right circumstances, contribute to a more stable regional environment.

Koizumi's own itinerary provides another clue.

His India visit follows Japan's broader engagement with Australia and comes shortly after the Japan-India Defence Policy Dialogue.

Australia and India occupy different geographic positions, but both are important nodes in Japan's expanding network of security partnerships.

Australia brings advanced defence-industrial cooperation and a deep alliance relationship with the United States.

India provides strategic depth in the Indian Ocean, a major defence-industrial partnership and access to South Asia.

Bangladesh adds another geographical layer.

Together, these relationships do not constitute a traditional alliance system.

They constitute something more flexible: a network of complementary strategic partnerships.

That may ultimately prove more useful to Japan than trying to construct a rigid bloc.

From The Himalayas To ASEAN

The network becomes even clearer when South Asia is viewed as a connected geographical space.

Japan's engagement with Nepal and Bhutan provides a Himalayan dimension.

India remains the principal strategic anchor.

India's north east acts as a continental bridge.

Bangladesh provides access to the northern Bay of Bengal.

The Indian Ocean provides maritime depth.

ASEAN connects this geography to the wider Indo-Pacific.

The resulting map is therefore: Himalayas-India-north east India-Bangladesh-Bay of Bengal-Indian Ocean-ASEAN. This is not a formal Japanese doctrine. It is an analytical framework.

But it helps explain why Japan's relationships with South Asian States increasingly need to be examined together rather than separately.

What This Means For India

For India, the implications are broadly positive -- but they require strategic clarity.

New Delhi should resist the instinct to view Japanese engagement with Bangladesh as inherently competitive.

Instead, India should seek to align Japanese regional engagement with its own connectivity and Act East objectives.

Japanese-supported infrastructure in the Northeast can reinforce India's regional integration agenda.

Japanese investment in Bangladesh can contribute to economic diversification.

Japanese maritime engagement can strengthen resilience in the Bay of Bengal.

And deeper Japan-India defence-technology cooperation can strengthen India's capabilities while contributing to wider Indo-Pacific stability.

The appropriate response is therefore not exclusivity. It is coordination.

India should not expect Japan to limit its engagement with neighbouring States in order to preserve India's primacy. It should instead encourage Japan to maintain a strong, balanced and long-term regional presence.

A Japan that is deeply engaged with India and constructively engaged with India's neighbours is ultimately more useful to New Delhi than a Japan confined to bilateral relations with India.

The Real Challenge For New Delhi

The challenge for India is therefore not Japan's engagement with Bangladesh.

It is India's ability to manage its own influence in a neighbourhood where external partnerships are becoming increasingly diversified.

Japan's distance gives it flexibility.

India's proximity gives it influence -- but also political exposure. That structural difference cannot be eliminated. It can only be managed.

New Delhi's objective should be to ensure that Japan's regional engagement reinforces India's position as the principal strategic anchor while allowing neighbouring states sufficient autonomy to avoid excessive dependence on any single power.

That is not a contradiction. It is the basis of a more resilient regional order.

India-Anchored, Bay-Of-Bengal-Oriented

Koizumi's visit should therefore not be viewed simply as another milestone in an already strong Japan-India relationship. It is part of a larger evolution in Japanese strategy.

Japan's 2026 defence framework increasingly connects national security with technology, intelligence, economic security, industrial capacity and cooperation with like-minded partners.

India sits at the centre of that framework.

But Japan's strategy does not stop at India's borders.

It extends into the north east.

From the north east, it connects to Bangladesh.

From Bangladesh, it reaches the Bay of Bengal.

From the Bay, it connects to the Indian Ocean and Southeast Asia.

The strategic proposition is therefore straightforward:

Japan is not moving away from India.

It is using India as the anchor for a broader conception of South Asia and the Indo-Pacific.

That is why Bangladesh matters.

That is why the north east matters.

And that is why the Bay of Bengal may become increasingly important to Japanese strategy.

The emerging geography is no longer simply Japan-India. It is: Japan-India-north east India-Bangladesh-Bay of Bengal-Indian Ocean-ASEAN.

Infrastructure projects such as the Dhubri-Phulphari bridge represent one layer of this connectivity. Matarbari represents another.

The Japan-Bangladesh defence-equipment agreement adds a security dimension, while the Japan-India defence and technology relationship remains the core strategic pillar.

The August 5 Sheikh Hasina episode adds another layer: The contrast between India's unavoidable political entanglement with Bangladesh and Japan's greater diplomatic distance.

For New Delhi, the question is therefore not whether Japan should engage Bangladesh.

It is whether India can recognise that Japanese engagement with Bangladesh can reinforce, rather than dilute, India's centrality.

That requires viewing South Asia not as a collection of bilateral relationships but as an interconnected strategic space.

Japan is increasingly moving in that direction.

India remains the anchor.

The Bay of Bengal is becoming the connective tissue.

And Japan's South Asia strategy is expanding without becoming less India-centric.

Varun Arya, who served with the Government of India, now serves as a geopolitical consultant for think-tanks. A freelance writer debuting with the novel The Last Living Fort, he also champions global artists through his platform, 'Create' by Mukul's Art Space.

Feature Presentation: Aslam Hunani/Rediff