India and Australia need to start cooperating in detecting, monitoring and understanding what’s going on underwater. As submarines, especially small, uncrewed ones, proliferate in the Indian Ocean and adjacent waters, neither country should regard itself as strong enough in this field.
Each can take advantage of the other’s strengths, such as technical research, industrial capacity and experience.
There is more at stake than just naval operations: all maritime economic and security architecture would be strengthened by cooperation between the two countries. The Indo-Pacific carries the global economy, with around half of the world’s maritime trade flowing through its waters and linking the energy wells of West Asia to refineries in South and East Asia. Critical chokepoints such as the Straits of Hormuz, Malacca, Lombok and Sunda are economic lifelines.
While maritime domain awareness (MDA) linkages between India and Australia address surface threats, risks and challenges, underwater activity remains barely monitored and increasingly contested, making underwater domain awareness (UDA) a vulnerability.
UDA is detecting, monitoring and understanding activities beneath the sea surface. It extends beyond traditional maritime surveillance, encompassing anti-submarine warfare, monitoring of undersea cables, deployment of uncrewed underwater systems and deep-sea environmental and resource intelligence gathering. This makes the underwater domain both technically challenging and strategically critical for individual countries and across the region.
The underwater domain is fast becoming the new frontier of strategic competition, and stakes are raising rapidly. Disruptions to critical undersea infrastructure, particularly submarine cables, can cripple financial systems and communications, impacting global connectivity and the digital economy. Advances in submarine technologies and the proliferation of uncrewed underwater vehicles are expanding the scope for covert operations, grey-zone tactics and strategic surprise.
Both countries are exposed to an increasingly assertive China, whose expanding maritime footprint and undersea capabilities are reshaping the regional balance.
A research report co-authored by me and issued last month argues that UDA cooperation creates an opportunity for India and Australia to strengthen their strategic partnership while contributing to a free, open, stable, and prosperous Indo-Pacific
Like others, India and Australia rely on security of trade routes and submarine cables. They are also exposed to an increasingly assertive China, whose expanding maritime footprint and undersea capabilities are reshaping the regional balance.
Since upgrading bilaterial ties through their 2020 Comprehensive Strategic Partnership, India and Australia have steadily strengthened defence engagement with deeper strategic and operational coordination. They must now boost cooperation in the underwater domain.
To do this, they should identify complementary strengths that, when combined, optimise outcomes. India can bring scale through industrial capacity, a growing defence manufacturing base and operational experience across the Indian Ocean. Australia can bring niche technological expertise, advanced research ecosystems and a strong focus on innovation in undersea systems. Together, these strengths can form a foundation for a robust and mutually reinforcing UDA partnership.
There are four priority areas that could further anchor this cooperation: anti-submarine warfare, uncrewed underwater vehicles, undersea search and rescue and deep-sea awareness.
Anti-submarine warfare is central to deterrence in an era of expanding undersea fleets. Uncrewed underwater vehicles offer scalable and cost-effective means of surveillance and denial. Undersea search and rescue capabilities can serve as a public good, enhancing regional trust and cooperation. Deep-sea awareness addresses one of the most underappreciated vulnerabilities in the Indo-Pacific security architecture, and that is mapping and knowing the domain in a similar vein to the surface and air domains.
The Australia-India partnership should set standards for underwater domain awareness cooperation before that domain becomes a strategic liability.
Each of these priority areas addresses capability gaps. Collectively, they offer a pathway for India and Australia to move from declaratory alignment to strategic and operational integration.
In addition to technological cooperation, there must be a shift in strategic thinking. UDA must be given distinct attention as an operational domain requiring dedicated doctrines, investment and institutional coordination. It should not be subsumed within broader MDA frameworks, as that will risk underestimating its complexity and significance.
To sustain the cooperation, the two nations should establish institutional mechanisms such as joint research initiatives, data-sharing frameworks, interoperable systems and coordinated deployment strategies.
Broader geopolitical strategies will benefit from comprehensive UDA cooperation. As the United States recalibrates its global posture and shifts towards burden-sharing, regional middle powers such as India and Australia will be more important in maintaining stability.
UDA is a domain in which both nations can exercise leadership without escalating tensions, while simultaneously enhancing transparency, resilience and deterrence. The Australia-India partnership should set standards for UDA cooperation before the underwater domain becomes a strategic liability.
Article reprinted with permission from the Australian Strategic Policy Institute's analysis and commentary site The Strategist.