The seabed doesn’t end at Southeast Asia

The 2026 Shangri-La Dialogue (Opens in new window) helped bring much-needed attention to the digital infrastructure of undersea cables, landing stations, pipelines and related. On the sidelines of the recent dialogue in Singapore, 17 countries launched the Guiding Principles for Underwater Infrastructure Defence Exchanges (GUIDE) (Opens in new window) to strengthen cooperation on what are often invisible challenges. Australia was among the participating countries, alongside partners from Europe, the Middle East, Oceania and Southeast Asia.

AUKUS is moving in the same direction. Australia, the United Kingdom and the United States announced a project under AUKUS Pillar II (Opens in new window) focused on advanced payloads and enabling systems for uncrewed undersea vehicles with delivery expected from 2027. The aim is to support the protection of critical seabed infrastructure, while strengthening undersea surveillance, logistics and wider maritime capability. Australian Defence Minister Richard Marles (Opens in new window) also warned at Shangri-La that the seabed has become a major field of contest.

This matters for Australia – and suggests Canberra’s rendering of the Indo-Pacific map should stretch further west, across the Indian Ocean, towards East Africa.

Much of Australia’s Indo-Pacific debate still looks north to Southeast Asia and east to the Pacific. Those theatres are vital. Yet the infrastructure that sustains connectivity does not stop at the South China Sea or the Strait of Malacca. It continues across the Indian Ocean (Opens in new window), through the Gulf, the Red Sea and along Africa’s eastern seaboard.

That makes East Africa harder to ignore. Maritime security, critical minerals and digital resilience already connect East Africa directly to Australian interests (Opens in new window). The seabed sharpens this point. Cable routes, landing stations, ports, fuel flows, mineral corridors and food-security supply chains bind the western Indian Ocean into the same strategic system as Southeast Asia, South Asia and Australia.

The geography is not abstract. The SEACOM cable (Opens in new window) connects South Africa, Kenya, Tanzania, Mozambique, Djibouti, France and India. The Eastern Africa Submarine System (Opens in new window) also runs along Africa’s eastern coast, with landing points linking the region into global digital networks. Djibouti, Mombasa, Dar es Salaam, Maputo and South Africa are not just local nodes. They are part of the infrastructure that allows data, finance, trade and security cooperation (Opens in new window) to move across the Indian Ocean.

Australia does not need to claim a leadership role in this space. Its comparative advantage may be more modest, but more useful. Canberra is well placed to help connect parts of the Indo-Pacific that continue to be treated separately, including East Asian capital and technology, Indian Ocean maritime security, and African infrastructure priorities.

This is where Australia’s partnerships with Japan, India, Singapore and South Korea are most useful. Japan brings experience in quality infrastructure and long-term development finance. India brings geography, naval reach and a growing western Indian Ocean presence. Singapore brings maritime governance, logistics and regulatory sophistication. South Korea brings technology, shipbuilding and industrial capacity. The Quad also offers Australia (Opens in new window) a way to work with partners already active in Africa without greatly expanding its diplomatic or aid footprint. Australia-Japan cooperation (Opens in new window) in East Africa offers a practical model for this engagement, particularly where maritime security, digital systems, critical minerals and development priorities overlap.

The western Indian Ocean offers several practical areas for cooperation – cable protection, port governance, cyber resilience, maritime domain awareness, fisheries monitoring, disaster response and critical infrastructure standards. None requires Australia to militarise its Africa policy. Quite the opposite. The strongest contribution would be to treat infrastructure resilience as both a security and development issue.

This also reflects a broader change in how global order now works. The rules governing strategic infrastructure are no longer the exclusive domain of treaties or formal alliances. They are increasingly shaped by standards, insurers, telecommunications firms, infrastructure financiers, technology providers and private operators, alongside environmental, social, and governance frameworks, especially where formal regulation is slow or fragmented.

That logic is already visible in AUKUS and the Quad (Opens in new window). One provides hard capability and technology development. The other offers a broader cooperative platform for maritime security, infrastructure, health, climate and regional resilience. Together, they show how power and cooperation increasingly operate in tandem (Opens in new window) across the Indo-Pacific.

East Africa should not be perceived as a distant add-on to Australia’s Indo-Pacific strategy, but as part of its western edge. The same logic that draws Australia into AUKUS, the Quad and maritime resilience should draw attention to cable routes, ports and resource corridors across the western Indian Ocean.

Shangri-La confirms that the seabed is now a major field of contest. The lesson for Australia should be wider than cables alone. The Indo-Pacific does not end at Southeast Asia, but runs beneath the Indian Ocean to Africa.