Why the Andaman Sea anchors India's eastern maritime strategy
The Andaman Sea occupies a narrow stretch of water between the Indian mainland and the Malay Peninsula, where the Bay of Bengal meets the Strait of Malacca. For New Delhi, this body of water is not a peripheral sea but a hinge point linking the Indian Ocean to the South China Sea, shaping how India projects power, secures trade, and engages with ASEAN economies.
Australia watches these waters closely from its northern shores. With Darwin sitting closer to the Andaman Sea than to many parts of the Indian Ocean, and with Perth serving as a hub for maritime domain awareness research, the country's own Indo-Pacific posture is shaped by what unfolds here. The Andaman Sea is, in practical terms, the maritime backyard for Australia's northern approach as much as for India's eastern flank.
The geography of a strategic chokepoint
The Andaman Sea is bounded by India's Andaman and Nicobar archipelago to the west, Myanmar to the north, Thailand to the east, and northern Sumatra to the south. Three narrow passages, the Six Degree, Ten Degree, and Preparis channels, funnel shipping through waters often less than a hundred nautical miles wide. These are the chokepoints through which much of East Asia's energy and Europe's containers transit to the Indian Ocean.
This geography gives India a rare advantage: a chain of islands stretching more than 700 kilometres astride the main shipping artery linking the Pacific to the Indian Ocean. The Andaman and Nicobar Command at Port Blair operates as India's only tri-services theatre command, reflecting the need for integrated air, naval, and land planning rather than a conventional base.
The islands allow persistent surveillance of the Strait of Malacca's western approaches, extending the reach of maritime patrol aircraft and enabling quick-reaction alerts and humanitarian assistance missions across the Bay of Bengal. For Australia, which maintains the Harold E. Holt naval communication station in Exmouth for similar monitoring, the value of forward-deployed sensors in the Andaman Sea is a familiar strategic lesson.
India's naval footprint in the eastern theatre
India's maritime posture in the Andaman Sea has matured since the early 2000s. Port Blair's docking facilities now accommodate larger combatants, runway upgrades at Shibpur and Campbell Bay support round-the-clock maritime reconnaissance, and joint exercises with Japan, Singapore, and the United States have become routine. The goal is not a carrier strike group in the eastern Indian Ocean but credible, layered resistance to any hostile movement through the Malacca approaches.
This matters given Chinese naval activity in the Indian Ocean Region. The expansion of China's Djibouti base, recurring research vessel deployments in the Bay of Bengal, and reported interest in dual-use Indian Ocean facilities have prompted India to harden its eastern defences. The Andaman Sea is where India can contest sea control without operating deep in the South China Sea, where distances and competing claimants make presence expensive.
For Canberra, the parallels are instructive. Australia's rotation of marines through Darwin and the expansion of training areas in the Northern Territory reflect a similar logic of denying easy access to potential adversaries. Both nations have concluded that geography is most useful when paired with habitual presence and political will.
Energy, trade, and sea lines of communication
Roughly half of global container shipping and a large share of liquefied natural gas bound for East Asia transit the Andaman Sea. India imports most of its crude oil through the Strait of Malacca, so any prolonged disruption would hit Indian refineries, power generation, and inflation directly. The strategic logic of securing the Andaman Sea is inseparable from the economic logic of keeping trade moving.
ASEAN integration adds another layer. India's trade with Thailand, Myanmar, Indonesia, and Malaysia moves overwhelmingly by sea, and connectivity projects like the India-Myanmar-Thailand trilateral highway depend on safe passage through these waters. The Andaman Sea is less a barrier than a bridge, provided freedom of navigation is respected and disputes managed through established legal norms.
Australia's LNG exports to Japan, South Korea, and increasingly India travel through these waters. A disruption would affect gas prices in Tokyo and Seoul, insurance premiums in London, and freight rates in Melbourne and Fremantle. This interdependence is structural, which is why maritime security here has moved from being an Indian concern to a shared Indo-Pacific responsibility.
Australia and the Andaman Sea in regional security
Australia's engagement is visible through participation in the Malabar exercises, the Quad, and bilateral dialogues on maritime domain awareness. Australian naval vessels visit Port Blair regularly, and the two navies cooperate on white shipping data, anti-piracy patrols, and submarine rescue. Canberra's Pacific Step-Up and AUKUS commitments are not directed at the Andaman Sea specifically, but they reinforce deterrence across the broader Indo-Pacific.
Domestic legislation shapes how Australia approaches these waters. The Foreign Influence Transparency Scheme and reforms to the critical minerals strategy affect how Australian companies engage with Southeast Asian partners and protect sensitive infrastructure. The Critical Technologies Policy Framework governs cooperation on undersea cables, satellite communications, and dual-use research, areas that intersect directly with maritime surveillance in the Andaman Sea.
The Australian Defence Force's focus on the northern approaches, including new patrol boats and maritime helicopters, reflects a recognition that Australia's maritime frontier is not the Tasman Sea but the seas to its north and west. Cooperation with India in the Andaman Sea is a natural extension of this shift.
Stewardship, strategy, and shared priorities
The Andaman Sea's strategic importance is inseparable from its ecological fragility. The archipelago's coral reefs, mangroves, and indigenous Nicobarese communities face mounting pressure from tourism, illegal fishing, and sea-level rise. India's approach blends environmental protection with community welfare, drawing on civilisational values of stewardship rather than purely utilitarian conservation.
This perspective extends beyond the Andaman Sea. As climate policy debates intensify across the Indo-Pacific, India's experience suggests ecological responsibility and strategic security can reinforce each other. Research from Indian institutions on India's civilisational approach to ecology illustrates how traditional knowledge systems integrate with modern conservation. Australia, with its own experience managing the Great Barrier Reef and Indigenous sea country rights, has natural points of dialogue.
Joint research on marine biodiversity, plastic pollution, and coral bleaching could become a durable area of bilateral cooperation, building trust between navies, scientists, and communities. The comparison that follows summarises how the Andaman Sea stacks up against a wider Indo-Pacific maritime zone, while the lists outline the drivers behind India's eastern posture and the challenges that could complicate it.
| Strategic dimension | Andaman Sea | Wider South China Sea / Indo-Pacific theatre |
|---|---|---|
| Width of key passages | Less than 100 nautical miles at narrowest channels | Open ocean in most areas, with contested islands and reefs |
| Sovereign base architecture | Indian tri-services command at Port Blair | Multiple claimants, no single sovereign hub |
| Shipping density | Very high, linking Indian Ocean to Pacific | High but dispersed across several sea lanes |
| Strategic depth for India | Direct reach from the Indian mainland | Requires extended logistics, overflight rights, and seabasing |
| Ecological sensitivity | High, with protected tribal reserves and reefs | Mixed, with intensive fishing and land reclamation |
Drivers shaping India's eastern maritime posture
- Proximity to the Strait of Malacca and its vital sea lanes
- Expansion of Chinese naval and research vessel activity in the Indian Ocean Region
- Growth in bilateral and minilateral exercises with Quad partners
- Need to protect energy imports and container trade with ASEAN economies
- Vulnerability of island ecosystems to climate change and illegal exploitation
Challenges that could complicate the strategy
- Limited submarine and undersea warfare capacity in the eastern theatre
- Gaps in logistics and basing infrastructure beyond Port Blair
- Sensitivity of Myanmar as a northern neighbour and its impact on connectivity
- Coordination difficulties among civilian agencies responsible for island governance
- Rising sea levels and extreme weather events affecting coastal military installations
Australia's role in supporting this maritime order will depend on continued investment in its own northern capabilities and on Indian and Australian defence planners finding concrete, mutually beneficial projects in the Andaman Sea. A useful first step would be a joint hydrographic survey of the Preparis Channel, shared between the Indian Navy's National Institute of Hydrography and the Australian Hydrographic Office, to update charts used by commercial shipping and build operational familiarity between the two services.