China vs US: The Undersea Cable Battle Across 12 Pacific Nations

On January 15, 2022, an underwater volcano near Tonga erupted with the force of a nuclear weapon. The Hunga Tonga-Hunga Ha'apai explosion sent a shockwave visible from space and triggered tsunamis across the Pacific. It also severed Tonga's single undersea internet cable — and cut the island of 100,000 people off from the global internet for five weeks.

What that outage revealed was not just infrastructure fragility. It revealed which nations control which cables, and what political consequences flow from those control relationships. In the Pacific, that question has a single underlying answer: the United States and China are fighting a cold infrastructure war across twelve island nations, using undersea cables, 5G towers, government buildings, and data centers as the weapons. The side that wins the connectivity argument gets something more valuable than bandwidth — it gets diplomatic alignment, military access options, and the ability to monitor the data flowing through the territory it controls.

Why Pacific Islands Are the Most Contested Territory in Digital Geopolitics

The Pacific Ocean covers a third of the Earth's surface. Within it, eleven independent island nations and dozens of territories and dependencies dot an area from Hawaii to New Zealand and from Japan to the coast of South America. Individually, these nations are tiny — Nauru has 10,000 people, Tuvalu has 11,000, Palau has 18,000. Collectively, they control enormous maritime exclusive economic zones (EEZs), they hold UN voting blocs that matter on Taiwan, and several sit astride the US military's strategic posture in the Western Pacific.

China identified these facts before the US re-engaged. Beijing's approach: build the physical infrastructure. Ports, roads, government buildings, and most importantly, telecommunications networks. When a nation's only undersea cable connects to a Chinese-controlled landing station, that nation's internet traffic flows through a chokepoint that can be monitored, throttled, or severed by the controlling party.

The US counter-move came later and came with more money: rival undersea cable projects funded through USAID, the US Development Finance Corporation (DFC), and military assistance, often with Japan and Australia as co-funders.

The Cable That Decided the Solomon Islands

The most visible example of the cable geopolitics playbook is the Solomon Islands. In 2018, Australia, the United States, and Japan blocked a Chinese-backed cable (the Huawei Marine Networks-built project) from landing in the Solomon Islands and Papua New Guinea. Instead, the three nations funded the Coral Sea Cable System, a 4,700km submarine cable connecting Sydney to the Solomon Islands and Papua New Guinea. Australia paid approximately AUD $137 million. The cable was completed in 2020.

The political outcome was the opposite of what the infrastructure investment was intended to produce. In April 2022, Prime Minister Manasseh Sogavare signed a security cooperation agreement with China — a document that, when leaked, showed provisions that could allow Chinese naval vessels to use Solomon Islands ports. The US and Australia sent emergency delegations. The diplomatic crisis revealed something the cable investment had obscured: infrastructure access and political alignment are different things, and China had been building the latter relationship for a decade through aid, party-to-party contacts, and business networks, while the US bet primarily on the cable.

In 2019, both the Solomon Islands and Kiribati switched diplomatic recognition from Taiwan to China on the same day — a coordinated diplomatic pivot that removed two of Taiwan's island allies simultaneously. The Solomon Islands government under Sogavare cited financial and development incentives. Kiribati cited the same.

Kiribati: The Canton Island Question

Kiribati presents the most strategic military geography in the Central Pacific. The nation straddles the equator across 33 atolls spread over 3.5 million square kilometres of ocean. Canton Island (Kanton Atoll) within Kiribati was used by US military aircraft as recently as the Cold War.

China has expressed interest in developing Canton Island's airstrip. An extended runway there would give Chinese military aircraft reach over the Central Pacific that no land-based alternative currently provides. Kiribati's internet infrastructure — sparse and slow by global standards — primarily routes through satellite (the fiber cable connecting Kiribati to the global network is limited). The country's diplomatic switch to China in 2019 means that infrastructure development, including any digital network expansion, now flows through Chinese-linked entities rather than US or Australian ones.

For developers and cloud architects: Kiribati's latency to AWS ap-southeast-2 (Sydney) is approximately 80-120ms via satellite. Latency to any Beijing-region cloud endpoint is 200ms+. The practical internet of Kiribati is Australia-oriented by physics regardless of diplomatic alignment, which creates a structural tension between where the politics point and where the data actually goes.

The COFA Tier: Marshall Islands, Palau, and Micronesia

Three Pacific nations maintain a fundamentally different relationship with the United States through the Compact of Free Association (COFA): the Federated States of Micronesia, the Marshall Islands, and Palau. Under COFA, US citizens can live and work in these nations without visas, and the US provides direct financial assistance in exchange for military access and strategic influence.

The COFA arrangements were renegotiated and extended in 2023-2024 — a priority for the Biden administration specifically because Chinese diplomatic efforts in the region were accelerating. The renewed compacts included significant funding increases, in part to prevent these nations from pivoting toward Beijing as smaller financial incentives proved insufficient to hold other islands in the US orbit.

Palau has remained one of Taiwan's remaining diplomatic allies (Taiwan now has approximately 12 formal diplomatic allies). The US subsidized an undersea cable connecting Palau to the global network (the Palau National Communications Corporation cable) with backing from the US DFC, completed to reduce Palau's dependence on satellite internet that was expensive and throttled.

The Marshall Islands hosts Kwajalein Atoll — the Ronald Reagan Ballistic Missile Defense Test Site — one of the most strategically important US military facilities in the Pacific. The Marshall Islands government's digital infrastructure is US-oriented by both COFA design and practical routing through US-affiliated networks.

Papua New Guinea: The Mining and Data Sovereignty Collision

Papua New Guinea (PNG) is the Pacific island region's largest country by both population (~10 million) and geographic size. It sits north of Australia and is economically significant for its mineral resources — copper, gold, and liquefied natural gas that Chinese mining companies have invested in heavily.

The PNG internet infrastructure situation directly illustrates the cable politics dynamic. The Coral Sea Cable (Australia-funded, blocking Huawei) reached PNG in 2020. But within PNG, the last-mile infrastructure — mobile towers, fixed-line networks, rural internet — involves Chinese equipment manufacturers in various segments of the supply chain.

In 2023, the US and Papua New Guinea signed a Defense Cooperation Agreement, adding PNG to the network of Pacific nations where the US has formalized military cooperation rights. The digital infrastructure question is embedded in this agreement: data sovereignty and communications security are explicit concerns when Chinese-built equipment operates in a country where US forces have access rights.

Tonga, Fiji, Vanuatu, and Samoa: The Huawei Middle Tier

Four Pacific nations form what analysts describe as the "Huawei middle tier" — countries where Chinese-built or Chinese-funded telecommunications infrastructure is present in significant portions of the national network, but where US or Australian diplomatic relationships prevent a full strategic pivot.

Tonga: The 2022 eruption that severed the Tonga cable (operated by the Tonga Cable company, with partial Chinese investment) accelerated Starlink deployment. Within weeks of the disaster, SpaceX had Starlink terminals operational in Tonga on humanitarian grounds. The replacement cable, repaired and backed by Asian Development Bank funding, came online approximately five weeks after the cut. The lesson encoded in Tonga's experience: a single undersea cable is a single point of failure regardless of who built it.

Fiji: Huawei has significant infrastructure in Fiji Telecom's network. Fiji's government has received both Chinese and Australian investment. The Fijian military has historical ties to Australia and New Zealand. The result is a split infrastructure: Chinese equipment in the network, Australian-aligned military relationships, and a government that hedges diplomatically between the two.

Vanuatu: China funded the construction of Vanuatu's government complex in Port Vila. Chinese infrastructure investment is visible across the island chain. A 2022 report from the Australian Strategic Policy Institute (ASPI) flagged potential dual-use concerns with Vanuatu's Chinese-built port facilities. Vanuatu has no comprehensive data protection legislation, which matters when deciding how data flows through its network infrastructure are governed.

Samoa: Huawei equipment is present in Samoa's Digicel network (Digicel was sold to Denis O'Brien but Huawei equipment remains in the network). Western Samoa (now officially just Samoa) and American Samoa (a US territory) are the same archipelago under different jurisdictions — a digital infrastructure border running through geographically adjacent populations.

Nauru: The January 2024 Pivot

Nauru deserves specific mention because it represents the most recent data point. In January 2024, Nauru — population 10,000, the world's smallest island nation — switched its diplomatic recognition from Taiwan to China. The switch came days after Taiwan's presidential election. China offered financial support for Nauru's development projects.

The practical consequence for digital infrastructure: Nauru's limited internet connectivity, which routes through the Southern Cross Cable (Australia-oriented), will now attract Chinese development interest in any future cable or digital infrastructure expansion. Whether Beijing builds a cable landing station in Nauru or funds a domestic digital project, the direction of political alignment changes what equipment gets installed and where data transits.

Starlink as the Third Path — and Its Complications

The Tonga eruption made Starlink a humanitarian hero in the Pacific. Within days of the disaster, low-earth orbit satellites provided connectivity independent of any undersea cable. For the Pacific's 33 island nations and territories, this represented something genuinely new: the first realistic alternative to either the Chinese or US-Australia undersea cable networks.

But Starlink is a SpaceX product, and SpaceX is a US commercial entity with complex US government relationships. For Pacific nations seeking genuine infrastructure independence — not wanting to be either in the Chinese cable network or the US satellite network — Starlink is not neutral. It is a different dependency with different characteristics.

Latency: LEO Starlink provides approximately 20-60ms latency, dramatically better than geostationary satellite (500-700ms) and comparable to undersea cable. For Pacific islands that have historically faced 150-300ms satellite latency, Starlink is a genuine capability improvement.

Data sovereignty: Starlink data transits through SpaceX ground stations. The specific routing depends on which ground station is closest. Pacific-region traffic routes through ground stations in Hawaii, Australia, or New Zealand depending on satellite geometry. US intelligence access to that data is governed by US law — FISA, NSL authority — not by the laws of the Pacific island nations through which it passes.

For governments evaluating Starlink deployment: the latency benefit is real, the data sovereignty concern is structurally similar to the Chinese cable concern, and the vendor lock-in is potentially stronger because of how Starlink's terminal hardware ecosystem works.

Developer and Cloud Infrastructure Read-Through

For engineers building applications that need to serve Pacific island populations, the infrastructure geopolitics translate to specific technical decisions:

CDN node coverage: Cloudflare and Fastly have edge nodes in Sydney, Auckland, Singapore, and Tokyo. Pacific island traffic to these nodes adds 80-200ms depending on the cable route. There are no major CDN edge nodes within the Pacific island region itself. For latency-sensitive applications (real-time payments, health applications, government services), this is a meaningful performance floor.

Cloud region choice: AWS ap-southeast-2 (Sydney) is the practical cloud region for Pacific islands given cable routing. Azure Australia East is the equivalent. GCP has no Pacific-region data center. Applications built for Pacific deployment should architect for 100ms+ baseline latency to the application layer.

Data residency: Several Pacific nations (specifically Samoa and PNG) have passed or are developing data localisation requirements. Applications that process financial data, health data, or government data may need to run locally — which practically means running on-premise or in Australian-edge cloud infrastructure rather than any hyperscaler region.

Network resilience: The Tonga outage demonstrated the single-cable risk. Applications deployed for Pacific audiences should use multi-path network design where possible — primary undersea cable plus Starlink backup — and should be designed to degrade gracefully under high latency (250-500ms Starlink backup mode vs 80-150ms cable primary).

Our Analysis: The Cable Is the Colony

The Pacific digital infrastructure competition is the clearest current example of what geopolitical analysts call "infrastructure diplomacy" — using the physical foundations of connectivity to create strategic dependencies that outlast any single diplomatic initiative.

China's playbook is efficient: build a cable, a port, or a government building. The physical infrastructure stays long after any particular leader who accepted Chinese funds is out of office. The data routing preference, the maintenance relationship, the spare parts dependency — all of these create structural alignment that political will alone cannot easily reverse.

The US counter-strategy — fund rival cables, expand COFA, push Starlink deployment — is more expensive and came later. The Coral Sea Cable cost Australia and the US hundreds of millions of dollars to redirect infrastructure that China had been building relationships toward for a decade.

The developer implication is this: when you deploy infrastructure in the Pacific, you are making a geopolitical choice whether you intend to or not. The cable your traffic routes through, the cloud region your data resides in, the CDN vendor whose edge node your packets touch — each of these is a link in a chain that terminates at either Beijing or Washington, regardless of what jurisdiction your users are in.

For cloud architects serving Pacific governments: data residency decisions made today will outlast multiple election cycles. The choice of whether to route government data through an Australian-hosted cloud region vs a Chinese cloud endpoint is not an IT decision. It is a sovereignty decision that the infrastructure team is making by default if no one else does.

Key Takeaways

• 12 Pacific island nations now have Chinese-built or Chinese-funded digital infrastructure components — from full cable systems to network equipment; the US and Australia funded rival cables (Coral Sea, East Micronesia, Palau) totaling hundreds of millions in DFC and USAID commitments
• Solomon Islands is the defining case study: Australian cable funding in 2018 did not prevent a Chinese security pact in 2022 — cable access and political alignment are different things, and China built the latter through a decade of party-to-party relationships
• Kiribati's Canton Island represents the strategic military geography that explains US and Chinese interest in what is otherwise a tiny atoll nation — extended runway access there reaches the Central Pacific
• COFA nations (Marshall Islands, Palau, Micronesia) are the US-anchored tier in the Pacific; 2023-2024 compact renewals included significant funding increases specifically to counter Chinese diplomatic expansion in the region
• Nauru switched from Taiwan to China in January 2024 — the most recent example of diplomatic realignment changing what digital infrastructure investment gets deployed in a country
• Tonga undersea cable cut (January 2022 volcanic eruption) accelerated Starlink deployment in the Pacific; LEO satellite provides genuine latency improvements (20-60ms vs 150-300ms geostationary) but routes through US jurisdiction ground stations
• Developer read-through: Pacific cloud architecture should target AWS ap-southeast-2 (Sydney), build for 100ms+ baseline latency, use multi-path network design (cable primary + Starlink backup), and treat data residency decisions as sovereignty decisions not IT decisions

Sources

• ASPI — China's influence in Pacific digital infrastructure
• Reuters — Solomon Islands signs security pact with China, April 2022
• AP — Nauru switches diplomatic recognition from Taiwan to China, January 2024
• CSIS — China's Pacific Island push: what it means for US strategy
• Brookings — The new COFA: what the Pacific compacts mean for US strategy
• Sydney Morning Herald — Australia funds Coral Sea Cable to block Huawei in Solomons and PNG
• The Guardian — Tonga volcanic eruption: submarine cable repair restores internet