1.1 From the Telegraph to Optical Fibre

Transmitting information efficiently has been a perennial challenge for human society. Submarine cable networks are now the connective tissue between terrestrial fibre networks and play an indispensable role in enabling the modern Internet and data transfer. Since the first networks were laid, these infrastructures have been primarily privately owned by myriad telegraph companies, telecommunication firms, and now big tech firms (known in the industry as ‘hyperscalers’), often through consortia arrangements. These infrastructures have evolved since the mid-1800s, technologically, commercially and strategically – issues this brief history examines.

Until the optical telegraph was operationalised in the eighteenth century, information transmission was limited to the speed of a horse or ship. Early telegraphy was enabled by optical telegraphs, which conveyed text via visual signals. To convey messages, signal towers were constructed at regular intervals (within sight distance) and affixed with semaphore rigs which were manipulated to pass messages. However, electrical telegraphy quickly replaced optical telegraphy. Electrical telegraphy used wires to transmit electrical signals between points. The first commercial electrical telegraph was operational by the mid-1800s, and efforts were made to insulate cables for subsea use. By 1852 London and Paris were connected by a submarine telegraph link, and Ireland was connected to London by 1853.Footnote ⁶ In 1866 the first transatlantic telegraph was completed, and lines were rapidly laid to India in 1870 and Australia in 1872. By 1902, with the completion of a network across the Pacific Ocean, Britain’s submarine cable industry had laid a truly global network – dubbed the ‘All Red Line’.Footnote ⁷ While cables were usually laid by telegraph companies for commercial gain, the British Admiralty, Colonial Office, War Office and Foreign Office’s ‘political reasons’ helped to justify these networks.Footnote ⁸ Indeed, according to academic Jill Hills, ‘the submarine telegraph cable extended the “space” of empire to facilitate the unification of territory into nation-states and to allow long-distance control of alien territories’.Footnote ⁹ Hills adds that despite the telegraph system being privately owned, the British elite perceived the network as a ‘strategic resource to be used for the defense of empire’.Footnote ¹⁰

Submarine telegraphy played a key role in various international conflicts. Global network expansion through British subsidies was instigated by conflict, including the Indian Mutiny, the Crimean War, the American Civil War, the Boer War and the First World War.Footnote ¹¹ At the outset of the First World War, Britain swiftly severed Germany’s submarine telegraph cables, and attacking/defending these infrastructures remained a key battleground throughout the conflict at a global scale. Cable laying and repair became a perilous task, requiring naval escorts due to the risk of attack. According to historian Jonathan Reed Winkler, ‘although most of the fighting between Germany and Britain occurred on the Western Front, it was the struggle for control over worldwide communications that made the war global’.Footnote ¹² In one prominent Indo-Pacific example in 1914, the German light cruiser SMS Emden was sunk by the Australian light cruiser HMAS Sydney in the Indian Ocean’s Cocos Islands, which the SMS Emden visited to destroy British telegraphy infrastructure. However, cable networks were not simply cut and severed but also comprehensively censored throughout the First World War, as part of a broader effort to disrupt and intercept enemy communications. The British implemented a vast system of censorship across its cable network, with an emphasis on restricting enemy naval or military information transmission, preventing false report circulation, collecting actionable military intelligence and denying the enemy commercial benefit.Footnote ¹³ British cable censors were located across the globe, from Egypt to Fiji and from Mauritius to New Zealand.Footnote ¹⁴

During the Second World War, submarine telegraph cables were again a key target as Britain both severed Germany’s subsea connections in the Atlantic and also censored other messages and deliberately slowed cable traffic.Footnote ¹⁵ In the Indo-Pacific, Japan took aim at submarine cable infrastructure, cutting or seizing most British, Dutch, French and American cables in East Asia following the Pearl Harbour attack and shelling Cocos Islands’ landing station in 1942.Footnote ¹⁶ By severing or seizing submarine cables, governments and militaries were forced to instead transmit messages via radio, which was more easily intercepted. For example, during the Second World War, two cables were severed off Vietnam’s coast near Saigon which connected Japan and which the Allies struggled to intercept.Footnote ¹⁷ By severing these Japan-operated cable networks, Japanese military communications instead transmitted wirelessly, which could more readily be intercepted and decrypted. Indeed, according to scholars Motohiro Tsuchiya and Kristi Govella, ‘as the construction of these cable networks is influenced by geopolitics so too is their destruction’.Footnote ¹⁸

During the early Cold War period, coaxial cables began to be laid on the seabed, enabling a far greater data-carrying capacity including multiple voice channels. Coaxial cables were able to transmit high-frequency signals at higher speeds which enabled radio, television and early Internet transmission. While few details exist about submarine cable sabotage during the Cold War period, several notable examples have been detailed. First, in 1959, after a high number of cable breaks occurred off Newfoundland, the Soviet fishing vessel Novorossiysk was boarded by the USS Roy O. Hale.Footnote ¹⁹ The Americans suspected the Novorossiysk of purposefully sabotaging cables and boarded the fishing vessel after complaints from cable operators AT&T and Western Union to examine the ship’s logs. Although the US Navy concluded publicly that it found no incriminating proof of intentional sabotage, this incident was the first ever enforcement action justified by the 1884 Convention for the Protection of Submarine Telegraph Cables.Footnote ²⁰ Second, through the 1970s the United States tapped Soviet military cables in the Sea of Okhotsk, north of Japan. Codenamed Operation Ivy Bells, this joint US Navy, US Central Intelligence Agency and US National Security Agency action targeted Soviet communications pertaining to nuclear intercontinental ballistic missile tests and capabilities. In order to tap the cable networks, US submarines installed recording devices, which were then retrieved and processed.Footnote ²¹ While Operation Ivy Bells was compromised in the early 1980s, as scholar Caitlin Morris notes, these taps ‘are credited as some of the most daring and successful intelligence operations of the Cold War’.Footnote ²²

During the 1980s, fibre optic cables were developed and replaced coaxial cables – which used light (rather than electricity) to transmit signals through thin glass threads. Fibre optic cables had a much greater carrying capacity, and the first transatlantic fibre optic cables operational in 1988 – TAT-8 – could carry 280 megabits per second, which equated to 40,000 telephone circuits. The first fibre optic cable to traverse the Pacific – Trans-Pacific Cable 3 (TPC-3) – was laid a year subsequent in 1989. Fibre optic cables were largely laid on the same routes as retiring coaxial cables, and as technology rapidly improved, cable carrying capacity sharply increased, meaning many optical fibre cables reached ‘economic obsolescence before technological obsolescence’.Footnote ²³ Optical fibre submarine cables rapidly replaced coaxial cables during the 1990s, dramatically increasing the flow of bits, enabling the Internet’s global commercialisation and its embedding into many facets of society.

Importantly too, the telecommunications industry underwent a dramatic transformation during the 1980s and 1990s as large state-owned telecommunications firms were broken up and privatised. During the 1980s American AT&T was broken up as Japan’s Nippon Telegraph and Telephone Corporation and Britain’s British Telecom were privatised, with France Telecom following in the 1990s.Footnote ²⁴ As a result, submarine cable network development was increasingly driven by profit, and a cable-laying boom ensued – eventually crashing in the late 1990s due to excess built capacity.Footnote ²⁵ However, despite the cable market crash, the boom resulted in a dramatic increase in global carrying capacity – while in 1988, 1,800 voice paths crossed the Pacific and submarine cables carried 16 per cent of transmission capacity globally, by 2003, 1.87 billion voice paths crossed the Pacific and cables carried 94.4 per cent of global data transmission capacity.Footnote ²⁶ Put simply, in the post–Cold War period, submarine cable networks became a key enabler of modern information flows and the indispensable backbone of the Internet, but not without controversy.

The role submarine cables played in Western signals intelligence collection efforts was laid bare in 2013 when former American intelligence contractor Edward Snowden leaked a large cache of highly security-classified documents to journalists. As the documents detailed, the US National Security Agency, sometimes in collaboration with Five Eyes international partner agencies and telecommunications firms, used submarine cable infrastructure to undertake ‘upstream’ collection – meaning intercepting transiting data from fibre optic cables and internet backbone infrastructure.Footnote ²⁷ As the leaked documents illustrated, upstream collection took place on a global scale including at cable network infrastructures located in non-Five Eyes countries. The Edward Snowden global surveillance disclosures – including revelations about indiscriminate Western cable interception programmes – sparked global controversy. According to American academic Jeffrey T. Richelson, the revelations ‘sparked one of the most significant controversies in the history of the U.S. Intelligence Community’.Footnote ²⁸ Importantly, and as this Element will detail, Snowden’s revelations sowed distrust of Western telecommunications infrastructure amongst various Global South nations at the time, with implications for supplier choices in the years that followed.

A significant commercial shift is currently changing the economics of submarine cable network installation and operation. While most cable projects in the past several decades have been owned and financed through consortia arrangements – whereby multiple (usually) telecommunications firms collaborate to install and share a new network – American big tech firms, also known as hyperscalers or content providers, are now driving the development of many new networks. These hyperscalers, most prominently Google, Meta, Amazon and Microsoft, can justify joining consortia or owning cables outright, principally to support their respective cloud services, video/audio calling, searches, video content distribution and increasingly so for artificial intelligence (AI) production (whether training or geographically dispersed inference). According to TeleGeography, a data research firm, AI is a ‘key driver of future long-haul demand’,Footnote ²⁹ and for cable networks entering service between 2024 and 2027, hyperscalers have invested in 100 per cent of trans-Atlantic routes, 80 per cent of trans-Pacific routes, and 77 per cent of routes in Oceania.Footnote ³⁰ By investing in these networks through a consortium, or indeed as the sole owner, these hyperscalers are able to build high-capacity networks; determine cable landing points which align with data centres; reduce costs; build redundancy and swap fibre pairs or partial fibre pair capacity with other hyperscalers or carriers.Footnote ³¹ As a result, traditional telecommunication carriers are no longer the principle users of international data capacity through submarine cables, and the ever-growing hunger for capacity from American hyperscalers is increasingly dictating new subsea network dynamics.

1.2 Submarine Cable Networks

As I stress in this Element, submarine cable networks are indeed ‘networks’ – consisting of many elements, materials and components which enable data to flow between the parts and the control centre. These networks are one sub-element of the Internet’s enabling infrastructure, which comprises various parts including routers, modems, media and exchanges. This section overviews various core elements of a submarine cable network to illustrate the network’s physicality and to highlight some technological developments.

Fundamentally, data is represented in ones and zeroes and transmitted by a network ‘packet’ through an optical fibre cable. Each packet consists of both control information (which directs the packet to its destination and is often referred to as a header) and the user data (commonly referred to as a payload). Importantly, modern optical fibre networks often distribute packets across multiple networks, which are re-assembled at the destination. When stored, data is generally kept within a semiconductor memory chip as electrons. To transmit packets rapidly between landmasses, data is generally transferred via a submarine cable or via satellite. As satellite data transmission is relatively slow and costly, submarine cable networks transfer approximately 98 per cent of international data traffic and are the backbone of the modern Internet. To transmit packets through submarine cables, data is transmitted optically by specialised lasers via optical fibres.

While specifics vary, modern submarine cables consist of various components, and the glass optical fibres are sheathed by multiple insulating layers.Footnote ³² The thin glass optical fibres at the core are insulated by silicone gel, ultra-high strength steel wires, a copper sheath, a polyethylene insulator, nylon yarn bedding, galvanised armour wires and tar-soaked nylon yarn.Footnote ³³ These cables, termed the wet segment, are often armoured and buried in shallower waters and near the coast, but in deep waters are laid on the seabed and are roughly the diameter of a garden hose.Footnote ³⁴ Long-distance cables are electrified by power repeaters, which are located at approximately 80-to-100-kilometre intervals. According to TeleGeography, as of early 2025 active and planned submarine cables total over 600, and in excess of 1.48 million kilometres of cable is currently in service.Footnote ³⁵

These cables are connected to terrestrial fibre networks via various shore-based infrastructures (also known as the dry segment). When a cable makes landfall, it generally passes through a beach manhole or a beach joint which connects to a cable landing station. While cable landing stations have historically been built near the beach manhole and connected via backhaul to data centres, now cable landing stations and data centres can be co-located, and numerous submarine cable networks often terminate at a single cable landing station. Cable networks are controlled by network operations centres and network management systems (which can often be operated remotely), which control and monitor network activity and performance. Finally, submarine cable networks are laid and repaired by a fleet of specialised vessels complete with highly trained crews. These cable ships, built with bow and/or stern sheaves, lay, maintain and repair the infrastructures. While some of these cable ships are owned and operated directly by the firm laying the networks, others are subcontracted to perform the task. Moreover, many cable repair vessels operate as part of a subscription-based maintenance repair agreement zone, while some are contracted directly by the cable operator in the event of a fault.

A variety of new sensor technologies are being integrated into submarine cable networks, which can be used to monitor network cable operations as well as the underwater environment. Various technologies, including but not limited to distributed acoustic sensing, state of polarisation sensing and distributed fibre sensing, are being deployed on networks to better observe network performance and to identify risks to networks in real time – enabling proactive repairs and even interdiction of ships or individuals which pose risks to cables. Additionally, some cables (described as SMART Cables – Science Monitoring And Reliable Telecommunication) are being fitted with oceanographic sensors which can be used to monitor environmental indices, including sea levels, climate and earth changes, tsunamis and earthquakes.Footnote ³⁶ These sensing and monitoring technologies have profound environmental and network security implications but also raise important questions about how intelligent commercial submarine cable networks could be utilised by militaries and security agencies to better monitor the underwater domain and, correspondingly, whether these infrastructures thus become legitimate military targets during a conflict.

When submarine cables are damaged, the cables are not always entirely severed. A ‘shunt fault’ occurs when the cable’s insulation is compromised, thereby disrupting the electricity flow to repeaters. Even though many cables are buried in relatively shallow water initially, damage is still possible, often due to seabed movements and subsequent cable exposure. Cable faults can occur due to a variety of issues, including component failure, dredging, geological incidents and abrasion. Many faults cannot be formally attributed, and the cause can remain unknown. As cable monitoring and sensing become more widely implemented, it is easier for cable operators to pinpoint fault locations and disrupt an external threat before damage occurs.

To safeguard and protect submarine telegraph networks from damage, various international legal and diplomatic initiatives have been undertaken. In May 1865 the International Telegraph Union was established with a mandate to coordinate international telegraph networks and to set standards and frameworks. In 1932 the International Telegraph Union was combined with the International Radiotelegraph Union to become the International Telecommunication Union – still operating in the modern era. Moreover, in 1884 key states signed the Convention for the Protection of Submarine Telegraph Cables which aimed to protect cable networks and set rules pertaining to submarine cable networks laying and installation. According to the Convention, outside of territorial waters:

However, according to Article 15 of the Convention, ‘it is understood that the stipulations of this Convention shall in no wise [sic] affect the liberty of actions of belligerents’.Footnote ³⁸ Article 26 of the 1958 Geneva Convention on the High Seas outlined how ‘all States shall be entitled to lay submarine cables and pipelines on the bed of the high seas’, adding that laying and maintenance should not be impeded, and due regard should be made to existing seabed infrastructure.Footnote ³⁹ Article 27 required states legislate measures to punish individuals who wilfully or through culpable negligence damage submarine cables within respective jurisdictions.Footnote ⁴⁰ The 1958 Geneva Convention on the Continental Shelf further outlined in Article 4 that continental shelf exploration and natural resource exploitation must not impede submarine cable laying or maintenance.Footnote ⁴¹ In the same year the International Cable Protection Committee (ICPC) was founded – comprising governments and submarine cable industry players – which aimed to improve cable security by providing a forum for technical, legal and environmental exchanges at a global level.Footnote ⁴²

The 1982 United Nations Law of the Seas Convention (UNCLOS) is considered the primarily legal regime for submarine cable protection in the modern era. According to Article 58, states are free to lay submarine cables within exclusive economic zones provided due regard is given to the rights and duties of the coastal state and comply with relevant local laws and regulations.Footnote ⁴³ Likewise, Article 79 outlines that all states can lay cables on continental shelfs.Footnote ⁴⁴ Importantly, Article 87 notes that all states are free to lay submarine cables in the high seas, and Article 113 requires states adopt legislation which establishes that conduct which interrupts or obstructs, or is liable to interrupt or obstruct, submarine cable networks – whether through culpable negligence or wilfully – a punishable offence.Footnote ⁴⁵ Many states do not fulfil this UNCLOS obligation to criminalise conduct which damages, or could damage, these seabed networks.

1.3 Perceived Infrastructural Vulnerability

As I argue throughout this Element, submarine cable networks are sites of acute geopolitical competition as these infrastructures first, rapidly transmit information between continents and islands; second, geographically traverse vulnerable maritime and coastal zones; and third, physically constrict data to limited static conduits, see Figure 2. I engage and expand each of these unique network characteristics in turn – to illustrate why submarine cable networks have historically been, and continue to be, a site of geopolitical contention and state control.

Figure 2

Submarine cable network characteristics driving state control.

Submarine cable networks transcend spatial boundaries and transmit information as bits at the speed of light. Importantly, the packets of data which flow through cable networks do not only cross international borders – but should be considered in a more holistic and comprehensive manner. Many submarine cable networks transmit information domestically within states – whether connecting an archipelago, connecting the mainland to islands, or across harbours or lakes. These cable networks may transmit information between states and dependent territories, within empires, to allies, to conflict zones, to multilateral diplomatic networks, to international organisations and between scientific bodies. The bits which these networks transmit enable critical infrastructure operations and our modern digital society relies on data flows for basic functioning – including financial systems, medical infrastructure, personal communications and government services. Put simply, a submarine cable network’s critical role in information transmission – which underpins the functioning of our modern society – drives state control and influence.

The second factor driving states to intervene in submarine cable networks in the way these networks traverse vulnerable maritime and coastal zones. According to scholars Christian Bueger and Timothy Edmunds, maritime spaces are subjected to unique vulnerabilities, including a greater propensity for interstate conflicts, extremism and terrorism, and blue crime.Footnote ⁴⁶ These networks are laid through the high seas, contested seas, maritime choke points, conflict zones and congested seabed areas. These networks routinely operate beyond state jurisdictions or within overlapping jurisdictions. As effective maritime domain awareness is unachievable by most states – especially underwater – the maritime environment in which these networks are laid is little understood and under-monitored. States’ ability to monitor or protect these static seabed infrastructures is limited by the unique challenges of operating in the maritime domain, often beyond respective jurisdictions or beyond the geographically imposed capacities of navies or coast guards.

Third, submarine cable networks constrict and aggregate data flows through limited and often geographically congregated conduits. Due to the considerable costs required to lay, maintain and operate submarine cable networks – which require a robust business case or considerable state subsidies – cable networks are limited in number and limited in geographic distribution. By virtue of this relative network scarcity (when compared with terrestrial fibre), submarine cable networks necessarily constrict data flows through limited conduits, resulting in perceived vulnerability. Specifically, these limited conduits enable states to censor network traffic and to otherwise control the data flows. The limitation on network conduits also simplifies signals intelligence collection, which can be concentrated in landing stations. By constricting data flows in this manner, states correspondingly place a high priority on both ensuring cable network suppliers are ‘trusted’ and ensuring repair capacity is sufficient to safeguard network uptime.

As a colleague and I have argued elsewhere,Footnote ⁴⁷ this current era of submarine cable competition differs from previous eras in four fundamental ways. First, the basic functioning of our modern societies relies on the connectivity provided by submarine cable networks (and indeed digital infrastructure more broadly) to a higher degree than in previous eras. Global annual bandwidth demand is rapidly growing,Footnote ⁴⁸ and according to one report, approximately US$10 trillion in financial transactions is facilitated daily through cables.Footnote ⁴⁹ While satellite data transfer is improving, space-based communications cannot match the speed and capacity modern submarine cables provide – making these seabed conduits an indispensable enabler of our modern digital society. Second, in the post–Cold War era, state sovereignty and direct control of these seabed networks have eroded due to privatisation. Scholar Brendon Cannon notes that ‘cables are not sovereign property as such. They are instead a mix of public and private and often involve consortium’.Footnote ⁵⁰ Third, and as I elaborate in Section 2, modern submarine cable competition in the Indo-Pacific is fuelled by Sino-US competition. Fourth, states in the modern era are taking a regional approach to cable security rather than being concerned with just the networks which connect it or its territories directly. As a result, foreign assistance budgets and other tools of statecraft are being mobilised to influence third-country networks. These four aspects – our unprecedented modern reliance on submarine cable networks, the post–Cold War decline of state cable industry control, modern Sino-US competition centred around technology and the regional state approach to cable security – distinguish this modern era of cable competition from those which preceded it.

1.4 Research Approach and Scope

At the outset, it must be noted that this Element primarily analyses civilian seabed critical infrastructure rather than military seabed cables and sensors. Indeed, the seabed hosts an array of military seabed infrastructures, including cables, sensors and hydrophones. The location and details of these infrastructures are generally security-classified and closely guarded military secrets. While this Element does engage with military postures, due to the limited availability of data with respect to military seabed infrastructure, this work is primarily focussed on civilian critical seabed infrastructure. In addition, while the seabed is increasingly congested due to seabed electricity cables, seabed gas pipelines, conduits associated with offshore energy extraction (renewable and fossil) and the prospect of seabed mining, this Element will focus its analysis on submarine telecommunication cables.

Moreover, while submarine cable networks are routinely severed and damaged by anchors, fishing equipment and natural incidents, this Element will focus primarily on state-based and malicious risks – risks which are more prominent in an era of heightened strategic competition. Data from the International Cable Protection Committee shows that of the 100–150 submarine cable faults which occur annually, none are verified to have been severed maliciously,Footnote ⁵¹ with the possible exception of the June 2025 conviction of a Chinese vessel captain for damaging a cable network off Taiwan.Footnote ⁵² However, these routine threats to submarine cable networks are generally well-managed by industry and usually do not result in state intervention. As I will establish in this Element, states in the Indo-Pacific are devising foreign and defence policies to secure cable networks in this era of heightened geopolitical competition and increased regional conflicts – an era in which cable interference and sabotage are re-emerging as a concern amongst Indo-Pacific leaders and officials. Another challenge in drafting this Element is the rapidly evolving nature of submarine cable policy, as cable incidents continue to occur and state responses mature. As such, the proceeding sections are an attempt to catalogue and analyse this developing policy domain, which will consolidate as the months and years progress. Lastly, this Element provided but a brief analysis of the international legal dimensions of submarine cable security, which has been analysed extensively elsewhere,Footnote ⁵³ to instead focus on Indo-Pacific security considerations.

2.1 Growing Submarine Cable Scholarly Literature

Various scholars have analysed how geopolitics and conflict have played out on the seabed and affected submarine cable networks. According to historian Daniel H. Headrick’s 1981 book The Tools of Empire: Technology and European Imperialism in the Nineteenth Century, cables were ‘an essential part of the new imperialism’.Footnote ⁵⁴ Specifically, in peacetime, cables were the lifeline for imperial business communications; in a crisis, cables were ‘valuable tools of diplomacy’ and in war, cables were ‘security itself’.Footnote ⁵⁵ Fellow historian Jonathan Reed Winkler’s 2008 monograph Nexus: Strategic Communications and American Security in World War I finds that the First World War demonstrated how ‘the imposition of censorship over the cables touching U.S. territory, the coordination of this with other forms of Allied censorship, and the creation of a wartime traffic monitoring group gave U.S. officials a taste of the great power to be gained from control of the cables’.Footnote ⁵⁶ Historian Paul Kennedy, writing in a 1979 edited volume chapter titled ‘Imperial Cable Communications and Strategy’ finds that between 1870 and 1914, Britain’s efforts to both build a comprehensive cable system and to effectively plan offensive and defensive seabed operations ‘strengthened the military bonds of empire in peacetime’, while also enabling Britain to ‘meet the hazards and shocks which a worldwide war could present’.Footnote ⁵⁷

While the above academic literature examines submarine cable security from the mid-1850s until the end of the First World War, less analysis has been dedicated to the Second World War or Cold War era. Despite this, as Sino-US geopolitical tensions intensify, and as conflict returns to the European continent, some scholars are positing analysis. Scholar Nicole Starosielski’s 2015 monograph The Undersea Network argues for a ‘counterintuitive’ understanding of global cable infrastructure which is ‘wired rather than wireless; semicentralized rather than distributed; territorially entrenched rather than deterritorialized; precarious rather than resilient; and rural and aquatic rather than urban’.Footnote ⁵⁸ Moreover, academic Peter J. Hugill finds that submarine cables are an ‘explicitly geopolitical construct, integral to the process of hegemonic maintenance, challenge, and response that has been ongoing among the polities at the core of the capitalist world economy’.Footnote ⁵⁹

Concurrently, a growing body of literature is emerging which assesses submarine cable security and international relations. Scholars Christian Bueger and Tobias Liebetrau’s 2021 article ‘Protecting Hidden Infrastructure: The Security Politics of the Global Submarine Data Cable Network’ warns that research ‘interest in cables has increased, but remains confined to a narrow technical debate, which does not pay attention to the politics of technology and the governance challenges that cables raise’.Footnote ⁶⁰ Scholar and diplomat Hilary McGeachy’s 2022 analysis titled ‘The Changing Strategic Significance of Submarine Cables: Old Technology, New Concerns’ argues that ‘submarine cables have “always” had strategic value’ and that ‘submarine cables provide a means to understand more about the concept of strategic technology competition’.Footnote ⁶¹ McGeachy finds that since 2015, both China’s efforts to establish Chinese firms in the cable supply chain and renewed government attention on ‘information-related companies and infrastructure’ have altered Western strategic assessments on submarine cable networks.Footnote ⁶² Also, legal scholars Douglas Guilfoyle, Tamsin Phillipa Paige and Rob McLaughlin’s 2022 paper contends that cables’ ‘increased utility, and the radically increased reliance of States upon submarine data cables for data transfer, serves to emphasise the potential consequences of their vulnerability to damage by malicious acts, accidents, or natural phenomena’.Footnote ⁶³

Some scholars have given specific attention to submarine cable policy in the Indo-Pacific. Scholar Kristi Govella argues that maritime and economic securitisation has altered the prevailing cable policy discourse, that in the Indo-Pacific specifically this new discourse is ‘already reshaping the physical layout of regional cable architecture’ due to investment decisions and that cable network resilience should be driven by a ‘whole life cycle’ strategy.Footnote ⁶⁴ Academic Brendon J. Cannon finds that the Quad can further work to strengthen cable security through developing ‘interagency coordination’ and ‘global governance’, as well as by ‘developing regional connectivity strategies’.Footnote ⁶⁵ Despite some Indo-Pacific nations – especially in the Pacific OceanFootnote ⁶⁶ – not accepting the securitisation discourse, scholar Tara Maria Davenport argues that the physical protection of these subsea networks is ‘an inherent component of “resilience”’.Footnote ⁶⁷ On Southeast Asia, analyst Elina Noor finds that ASEAN nations are increasingly being forced to choose between Chinese or American subsea networks, which is consequently fragmenting subsea digital connectivity.Footnote ⁶⁸ These scholars collectively echo that submarine cable security cannot be considered in isolation and indeed should be situated at the intersection of the prevailing geopolitical rivalry.

2.2 Sino-US Tech and Internet Competition

China and the United States are engaged in an intense battle for supremacy in the Indo-Pacific. Both states are competing for military, cultural, institutional, economic and technological superiority. According to Eric Schmidt, former Google CEO, Sino-US technology and innovation competition is the ‘century defining contest’.Footnote ⁶⁹ China has rapidly risen as a great power and is attempting to dislodge the United States in various domains, especially in networks. According to scholars Kai He and Mingjiang Li’s writing in 2020, ‘US–China strategic competition has just begun.’Footnote ⁷⁰

Various scholars agree that technology and innovation is a key contributor to great power status. According to historian Paul Kennedy, military power relies on a strong economy, which in turn requires superior technology.Footnote ⁷¹ Kennedy asserts that the relative power of states and empires is determined by the effect that economic and technological change has on social structures, governance arrangements and military power.Footnote ⁷² Political scientist Robert Gilpin finds that superior military and industrial technologies allow states to ‘seize the opportunities or overcome the constraints provided by the external environment in order to advance its economic, security, or other interests’.Footnote ⁷³ Put simply, cutting-edge technology and robust innovation are key drivers of power in the international system of states.

In recent years, China has invested heavily in high-tech innovation and rapidly climbed the economic value chain. Chinese tech firm HuaweiFootnote ⁷⁴ has led the charge in many of these technologies, especially in the telecommunications domain. According to scholars Andrew B. Kennedy and Darren J. Lim, innovating information and communication technologies have been a focus for China, underpinned by considerable increases in R&D expenditure.Footnote ⁷⁵ As technological prowess relates to international relations, Kennedy and Lim argue that ‘under certain conditions the rising state’s [technological innovation] activities will generate negative order externalities for the dominant state, particularly by undermining its preferred rules, practices and institutional arrangements’.Footnote ⁷⁶ Despite these negative order externalities, political scientist Daniel Drezner highlights that ‘technological latercomers’ often struggle to gain global market share as ‘the ingredients for motivating technological catch-up are ill-suited for technological leadership’.Footnote ⁷⁷ In any case, in the eyes of many first Trump Administration officials, Huawei was a strategic rather than a commercial challenge, as ‘Huawei was a national champion of America’s primary geopolitical rival’.Footnote ⁷⁸

Sino-US technology competition takes a variety of forms and extends into competition for Internet-related technologies. From AI, 5G telecommunications, e-commerce and digital payments, to social media, quantum computing and semiconductor manufacture, American and Chinese firms are competing for supremacy. Indeed, in Internet standards and governance, the two nations advocate for differing governance conceptions (multistakeholder vs state-centred), and China is advocating to replace the long-established TCP/IP (Transmission Control Protocol/Internet Protocol) with a ‘New IP’, which would incorporate greater controls at the network level.Footnote ⁷⁹ Furthermore, Sino-US technological competition extends beyond just the two superpowers and extends to respective partners and allies. Scholar Xinghua Liu finds that the United States does not further its technological leadership unilaterally but employs a ‘digital coalition’ model, in coordination with like-minded allies and states, to compete technologically with China.Footnote ⁸⁰ In this sense, allies and partners play key roles in operationalising the superpowers’ technological and innovation agendas and in enabling technological supremacy.

As this analysis illuminates, the United States and China are locked in entrenched competition across a variety of domains, crucially, including technology innovation generally and Internet leadership specifically. This rivalry, in the context of Sino-US network-based competition and physical infrastructure characteristics I outline below, aids in understanding why submarine cable networks have become a key battleground, especially when compounded against the European seabed warfare harbinger, as the next section outlines.

2.3 Network-Based Competition and Weaponised Interdependence

The contemporary Sino-US rivalry can be understood as ‘network-based competition’ – meaning a contest for centrality in digital, infrastructure, production and financial networks.Footnote ⁸¹ In this framework, posited by academic Seth Schindler and colleagues, the dominant components of networks are interconnectivity, interdependence and control of non-linear often non-hierarchical nodes.Footnote ⁸² This framework builds on international relations scholarship which illuminates the role of infrastructure in international relations,Footnote ⁸³ and the importance of political, economic and social linkages and networks.Footnote ⁸⁴ Furthermore, this framework builds on existing theorising concerning connectivity geopolitics,Footnote ⁸⁵ and the ways in which power in the international system is not ‘uniform or continuous over space’ but is dependent on a combination of ‘proximity and reach’.Footnote ⁸⁶

Through this lens, state control of data, knowledge, technical standards, capital and production capacity affords network leverage, which in turn is a source of hegemony in the international system.Footnote ⁸⁷ Hegemony under this approach affords the ability of a state to ‘order relations among actors’.Footnote ⁸⁸ This approach is based on both critical geopolitical economy scholarship and contemporary Cold War historiography.Footnote ⁸⁹ Rather than relying on a realist approach which emphasises structural conditions and the anarchic global system, this network-centric approach highlights the interconnected nature of modern international relations in which ‘network centrality’ is a key state goal.Footnote ⁹⁰ According to Schindler and colleagues:

Scholar William Kindred Winecoff highlights that under this ‘network approach’, the United States will maintain predominance if other states continue to integrate into US-led networks, but that interdependence can result in other states feeling threatened by such ‘hierarchical patterns of interdependence [resulting in these states] seek[ing] to resist exposure by forming alternative clubs’.Footnote ⁹² Moreover, scholars Robert O. Keohane and Joseph S. Nye, Jr describe a ‘“policy-networks” model of governance’, through which ‘interdependence’ results in ‘continuing interactions’ amongst players.Footnote ⁹³ They also argue that within limits, ‘asymmetrical interdependencies’ can be considered ‘sources of power among actors’.Footnote ⁹⁴

Connected to network-based competition, the concept of ‘weaponised interdependence’ was first articulated by academics Henry Farrell and Abraham Newman in 2019 to describe how network interconnectedness can afford exploitable benefits to states with jurisdictional (whether physical or legal) control over network nodes and vulnerabilities for those without.Footnote ⁹⁵ Importantly, networks are often structured asymmetrically, meaning some nodes are more comprehensively connected than others, meaning interdependencies can be leveraged.Footnote ⁹⁶ According to Farrell and Newman:

Under the weaponised interdependence framework, two forms of weaponisation are described – the ‘panopticon effect’ and the ‘chokepoint effect’. The panopticon effect refers to the way in which states with jurisdictional or physical access to network hub nodes can use their position of network centrality to intercept and glean information which is otherwise transiting the hub – offering a ‘key window into the activity of adversaries’.Footnote ⁹⁸ The ‘chokepoint effect’ refers to the ‘coercive power’ network centrality provides states, allowing hub access by other states (or indeed firms) to be limited or penalised for strategic reasons.Footnote ⁹⁹ Importantly, Farrell and Newman find that to harness both the panopticon and chokepoint effects, states need both network hub jurisdictional control and ample legal and regulatory ‘institutional capacity’.Footnote ¹⁰⁰

The weaponised interdependence idea was first articulated as a warning to government officials against the unintended effects of leveraging network access and network choke points. By exploiting interdependence, fellow states may likewise attempt to leverage networks, to disengage from networks or to reduce vulnerability by revising networks.Footnote ¹⁰¹ As Farrell and Newman write, ‘the more that privileged states look to take advantage of their privilege, the more that other states and nonstate actors will take action that might potentially weaken or even undermine the interdependent features of the preexisting system’.Footnote ¹⁰² Therefore, states would be wise to resist weaponising interdependence, so centralised exchanges can continue to deliver universal benefits. However, it seems some US officials adopted the idea as a strategy. Writing several years after first positing the weaponised interdependence concept in 2019, Farrell and Newman noted that at least one Trump Administration officials had read their academic article and concluded that weaponising choke points was sound policy.Footnote ¹⁰³ According to academic Chris Miller in his book Chip War, while discussing Huawei with a former senior US official, the source commented: ‘weaponized interdependence … it’s a beautiful thing’.Footnote ¹⁰⁴

However, the degree to which states could indeed weaponise interdependence in submarine cable network dynamics has been questioned. Scholar Lars Gjesvik argues that, while ‘seemingly ripe for state exploitation as digital infrastructures become more critical, the second incarnation [2010 onwards] of the [submarine cable] network has instead empowered private corporations and given them greater ability to resist state attempts at weaponization’.Footnote ¹⁰⁵ Gjesvik’s analysis centred on trans-Atlantic cable networks. Indeed, the private ownership of these seabed networks will limit the degree to which states can intervene and interfere. Rather, through this present Element I seek to articulate how and why states are attempting to control these networks, rather than the success or otherwise of the resulting interventions (which is engaged with in Section 5), vis-à-vis private actors.

Moreover, scholars Dwayne Woods and Junda Li apply the weaponised interdependence framework to submarine cable networks in their 2024 article ‘Dangerous Depths of Bifurcation: The Rise of “Inter-National Security Narcissists” and Undersea Cable (Dis)Connections’, arguing that the framework ‘falls short in accounting for the proactive reshaping of network topologies by states seeking to mitigate these very vulnerabilities’.Footnote ¹⁰⁶ When it comes to submarine cable networks, using a sequential game model, Woods and Li find that in response to perceived cable network vulnerability, both China and the United States have respectively attempted to construct parallel (or bifurcated) networks, which has resulted in the ‘fragmentation’ of the global cable system – a phenomenon the weaponised interdependence framework had not previously accounted for.Footnote ¹⁰⁷ While Woods and Li model bifurcation as a response to vulnerability, this Element identifies the mechanisms through which key Indo-Pacific states reshape network topologies, utilising a novel nodes-flows-production typology to understand how states seek centrality – not just how centrality is mitigated.

Building on this growing astute scholarship, this Element is unique due to the way it catalogues both the global dynamics pertaining to submarine cable vulnerability and how key Indo-Pacific states have adapted foreign and defence policy. Moreover, this present treatment’s novel categorisation of state responses to perceived cable insecurity is a defining feature, in addition to the network-based competition lens which guides analysis and illustrates how Sino-US competition over submarine cable networks can inform competition in other network domains – including digital, infrastructure, production or capital.

2.4 Infrastructural Control Imperatives

I now turn to identify three imperatives which are driving new foreign and defence policies associated with submarine cables in the Indo-Pacific. These imperatives are nodes, flows and production (see Figure 3). Each of these factors is illustrated in turn and used as a typology in Section 5 to illustrate how states are attempting to attain and maintain centrality in submarine cable networks.

Figure 3

State Submarine Cable Control Imperatives.

Nodes refers to the submarine cable network’s physical geography and chokepoint positioning. Specifically, nodes consist of the physical network, including landing station locations, cable routes and interconnection (branching) points. By influencing and controlling network nodes, states can determine the contours of data flows and include or exclude fellow states in global data flows. States can attain forms of network centrality by controlling network nodes – creating privileged positions for themselves and/or allies/partners in data flows and through excluding others. Importantly, nodes denote the physical architecture of data connectivity, and centrality or control can be leveraged for strategic or economic gain.

Flows denote the data stream which transits submarine cable networks, such as Internet traffic, AI inference, cloud data or government communications, transferred across international boundaries. Controlling data movement is significant for states, whether defending flows from interruption or sabotage or exploiting for espionage or signals intelligence purposes. In this sense, flows create both a vulnerability and an opportunity for states – and this aspect is driving states to adopt policies which enable better control over data transmission.

Production pertains to the entire submarine cable network supply chain, from materials and components to specialised installation and repair capacities. These firms and supply chains are significant as the owners, operators, builders and repairers of this infrastructure are primarily privately owned. Due to the concentrated nature of this specialised and sensitive industry, which operates at a global scale, many states are reluctant or unwilling to rely on suppliers headquartered in countries deemed politically untrustworthy. By developing sovereign or allied supply chain capacity, states reduce dependence on adversary suppliers for cable installation and repair, thereby avoiding vulnerabilities that could enable network exploitation.

These state imperatives are interconnected and are mutually reinforcing. For example, controlling nodes can better enable defence and exploitation of flows, and state influence over production can afford power over nodes. Section 5 employs this novel framework to analyse how various key Indo-Pacific states are attempting to attain positions of network centrality in submarine cable nodes, flows and production.

2.5 Conclusion

This section posited the analytical framework employed throughout this Element. Network-based competition illustrates how states compete for centrality in infrastructure networks, and weaponised interdependence demonstrates how these infrastructures can be exploited through the panopticon and chokepoint effects. My novel nodes-flows-production typology is a useful lens to understand how states in the Indo-Pacific are intervening in submarine cable networks, securing central network positions that reduce vulnerability but can create the structural conditions that risk weaponisation. The next section shifts focus to examine various suspicious cable incidents in Europe and the Indo-Pacific, which in combination have driven increased state intervention in this strategic communications domain.

3.1 European Waters

While the European incidents occurred in the context of Russia’s hybrid warfare campaign against NATO states during the Ukraine conflict, rather than driven by Sino-US competition, these nonetheless illustrate how geopolitical rivalry can manifest as seabed insecurity, thereby generating the climate of uncertainty and fear that is driving new cable policies. Instances of suspectedFootnote ¹⁰⁸ seabed warfare, which hadn’t taken place since the Second World War, emerged as a key security concern in many European capitals as acts of suspected cable sabotage abounded. While these cases occurred in European rather than Indo-Pacific waters – the subject of this Element – these cases are nonetheless relevant for several reasons. First, while occurring in Europe, these incidents made headlines globally, meaning relevant government and military officials across the Indo-Pacific would have been (at minimum) aware of the incidents. Second and relatedly, these incidents demonstrated to officials outside Europe how possible modern grey-zone seabed warfare tactics can play out and how submarine cables can be targeted, in the context of a major continental war, in this case between Russia and Ukraine. Third, these cases demonstrate the strategic and commercial impacts of multiple simultaneous cable breaks under suspicious circumstances. Fourth, Europe’s policy, legal and military responses illustrated to non-European states the options available to secure submarine cable networks, which could be adapted to local (in this case Indo-Pacific) contexts. Ultimately, I understand these European cases as a ‘harbinger’ for Indo-Pacific states, which have prompted new policy responses, as detailed in Section 4.

3.2 Indo-Pacific Seabed Insecurity

In the Indo-Pacific, cable insecurity has emerged across two distinct regions: the waters off Taiwan, where repeated incidents have been linked to Chinese-flagged vessels, and the Red Sea, where Houthi attacks on merchant shipping have imperilled critical intercontinental cable routes. These regions are addressed in turn.

3.3 Taiwan

Submarine cable networks are routinely fouled in the waters off Taiwan – especially cable networks which connect Taiwan’s outer islands located in the Taiwan Strait. Media reports have swirled for several years about suspicious damage to Taiwan’s submarine cable networks.Footnote ¹⁶² Indeed, according to one report, between 2019 and 2023 Taiwan recorded thirty-six cable incidents associated with its submarine cable networks.Footnote ¹⁶³ As a result of these incidents – and China’s ongoing provocations against the state – Taipei is working actively to protect its digital seabed links.

Much of this cable insecurity is concentrated in the waters off Taiwan’s Matsu Islands. The second of two networks which connect Taiwan’s Matsu Islands was severed in May 2022, causing a ten-day Internet outage, relatively short due to the fact that repairs had already been arranged for the first fouled cable.Footnote ¹⁶⁴ Then, in February 2023, two submarine cables which connect Taiwan’s outlying Matsu Islands were severed in a six-day period, first by a Chinese fishing vessel and subsequently by the anchor of a Chinese cargo ship.Footnote ¹⁶⁵ The 13,000 residents of Taiwan’s Matsu Islands were effectively left without Internet access for 50 days until the first cable network was repaired, with severely limited connectivity provided by a microwave radio transmission system which prioritised critical government communications.

Further concerning incidents took place in 2025. On 3 January 2025, Taiwanese authorities briefly detained the Cameroon-registered vessel Shun Xing 39, suspecting it of dragging its anchor over – and as a result severing – the US-bound Trans-Pacific Express submarine cable.Footnote ¹⁶⁶ Due to inclement weather, the vessel could not be boarded and subsequently departed Taiwanese waters. The vessel was thought to be owned by a Hong Kong firm linked to China and operating with a Chinese crew. According to Taiwan’s Coast Guard with reference to the incident: ‘we cannot rule out the possibility of a Chinese flag-of-convenience ship engaging in grey-zone harassment’.Footnote ¹⁶⁷ Lloyd’s List Intelligence reported that the vessel indeed had three identities – Tanzania-flagged Xing Shun 39, Cameroon-flagged Shun Xing 39 and Cameroon-flagged Xing Shun 39 – a ‘deliberate deceptive practice’.Footnote ¹⁶⁸

Just one month subsequent, on 25 February 2025, the Taiwan-Penghu No. 3 subsea cable system was severed. According to reports, the Togolese-registered and China-linked cargo ship Hongtai 58 (also known as Hongtai168) was anchored above the cable network for several days and did not respond to radio warnings to depart the cable grounds for fear of fouling the seabed networks.Footnote ¹⁶⁹ The cable network was severed on 25 February 2025, and the Taiwanese Coast Guard swiftly intercepted the vessel, escorted it to Anping (on Taiwan’s south-west coast) and boarded, detaining its crew.Footnote ¹⁷⁰ In response, Beijing accused Taiwan of ‘manipulating’ China’s involvement before the facts could be established.Footnote ¹⁷¹ Despite Beijing’s protests, in June 2025 a court in Taiwan convicted the ship’s captain to three years imprisonment for damaging the submarine cable network with an anchor, noting that ‘the impact is enormous, and the defendant’s actions should be severely condemned’.Footnote ¹⁷²

As a result of these incidents, Taiwan is attempting to alleviate its dependency on submarine cable networks by investing in alternative data transmission methods. The country is pursuing advanced satellite systems and investing in its indigenous space industry.Footnote ¹⁷³ As an interim measure, Taiwan has developed communications balloons, which Wu Cheng-wen, Taiwan’s science and technology minister, described as an ‘intermediate solution’ to restore emergency communications.Footnote ¹⁷⁴ Improvements to Taiwan’s telecommunications legislation – which would boost prison sentences and fines for cable damage – were also pursued.Footnote ¹⁷⁵ In October 2025 Taiwan launched a new global initiative to enhance submarine cable security, dubbed the Management Initiative on International Undersea Cables, also known as ‘RISK’ an acronym for risk mitigation, information sharing, systemic reform and knowledge building.Footnote ¹⁷⁶ According to Taiwan’s Foreign Minister Lin Chia-lung, the initiative is a ‘global partnership’ and that Taiwan’s experiences ‘have taught us an important lesson – resilience cannot be taken for granted. It must be built through planning, implementation, and cooperation’.Footnote ¹⁷⁷

It is unclear whether these concerning incidents involving submarine cables in Taiwan’s waters are accidental, negligent or malicious. Moreover, no concrete links have been made between these incidents and Beijing, or indeed the Baltic Sea incidents. Indeed, the waters off Taiwan are busy shipping routes, frequented by fishing and other commercial vessels and dredging is common. However, these incidents have been perceived by some as Chinese provocations, testing Taiwan’s resolve and response or the strength of the US–Taiwan relationship,Footnote ¹⁷⁸ possible probes ahead of a future invasion.Footnote ¹⁷⁹ Whether or not these beliefs are valid, the relatively high number of submarine cable incidents off Taiwan’s coats has contributed to a regional discourse of seabed insecurity, prompting defensive initiatives.

3.4 Conclusion

These incidents have transformed the public perception of submarine cable infrastructures from hidden data conduits to critical liabilities and targets. Europe’s spate of cable cuts, blamed on Russia’s hybrid operations, has prompted a militarised response, evidenced through NATO’s Baltic Sentry and respective national cable protection strategies. In the Indo-Pacific, repeated incidents off Taiwan indicate possible grey-zone Chinese activity, and Red Sea instability shows how conflict imperils global connectivity through repair delays. In sum, these incidents indicate that cables are vulnerable and that attributing incidents (legally or otherwise) can be challenging. While several major Indo-Pacific interventions preceded these incidents, these incidents since 2022 have validated early concerns and accelerated competitive positioning. The next section details key Indo-Pacific state policy responses that began in the mid-2010s and intensified following these incidents, showing how states compete for network centrality amid renewed recognition of cable vulnerability.

4.1 BRICS

One of the first attempts at challenging Western submarine cable network dominance in the post–Cold War era was undertaken by the BRICS. The grouping, which then consisted of Brazil, Russia, India, China and Saudi Arabia (but has since expanded), in 2012 sought to construct a 34,000 kilometre submarine cable network, dubbed the ‘BRICS Cable’.Footnote ¹⁹¹ It was hoped that the BRICS Cable, expected to cost US$1.5 billion and operational by 2014, would better facilitate communications between the bloc and, in turn, promote trade and investment amongst the grouping. The BRICS Cable network would also better connect Africa (through South Africa) with BRICS member nations.Footnote ¹⁹² The proposed cable network was turbocharged in 2013 when US National Security Agency contractor Edward Snowden disclosed a cache of highly classified documents to the media, many of which overviewed how the United States and its allies monitor and intercept data flowing through submarine cable networks, a practice known as ‘upstream’ collection.Footnote ¹⁹³ The Snowden Disclosures gave BRICS members another reason to pursue a submarine cable network – to safeguard data integrity by routing around US and Western signals intelligence collectors. According to analyst Lane Burdette, Brazil was a key proponent of the BRICS cable network, as the South American nation perceived an overreliance on US data routing.Footnote ¹⁹⁴

In 2015 the BRICS cable idea was shelved. While the exact reason for the project’s failure is murky, some blame a lack of finances,Footnote ¹⁹⁵ while others point to a lack of cohesion amongst the grouping.Footnote ¹⁹⁶ According to scholar Daya Kishan Thussu, the BRICS Cable ‘would have been a symbolic act of di-Americanizing the infrastructure of the Internet’.Footnote ¹⁹⁷ Although the BRICS cable never eventuated, BRICS leaders continue to prioritise digital infrastructure. According to the 2024 Kazan Declaration, member states are encouraged to ‘explore the possibility for joint activities in the field of digital infrastructure to ensure the integrity, stability of the functioning and security of national segments of the Internet’.Footnote ¹⁹⁸ The failed BRICS Cable case demonstrates how both economic and security imperatives drove an attempt to intervene in the submarine telecommunication network ecosystem.

4.2 China

In this era of heightened international tensions, China is actively furthering regional connectivity via submarine cable networks in line with its national interest – as Beijing considers cable networks a security concern.Footnote ¹⁹⁹ This section outlines China’s political-level strategy including its Belt and Road and Digital Silk Road strategies, its growing cable industry and how its illegal claim over the South China Sea is deleteriously affecting submarine cable connectivity for neighbouring nations.

4.3 The Quad

The preceding analysis groups the United States, India, Australia, Japan and India under a Quad umbrella, as this grouping has centralised various submarine cable network security initiatives. As such, the preceding analysis will detail common Quad initiatives before shifting to focus on how each Quad state is progressing on submarine cable security issues unilaterally. However, the preceding analysis proves that the unilateral versus multilateral distinction can be ambiguous, and at the time of writing, many of these efforts are still latent. The Quad grouping first announced its plans to shape submarine cable networks in May 2023 via a new ‘Quad Partnership for Cable Connectivity and Resilience’.Footnote ²²⁹ At that time, according to a joint statement, the partnership was intended to ‘strengthen cable systems in the Indo-Pacific, drawing on Quad countries’ world-class expertise in manufacturing, delivering and maintaining cable infrastructure’.Footnote ²³⁰ As part of this partnership, Australia agreed to establish the ‘Indo-Pacific Cable Connectivity and Resilience Program’, later renamed the ‘Cable Connectivity and Resilience Centre’ and analysed below.Footnote ²³¹

On 21 September 2024, Quad heads of state released ‘the Wilmington declaration’ at the fourth Quad Leaders’ Summit. In noting that ‘the Quad is here to stay’ and that ‘robust funding’ will be directed at Quad priorities, the Declaration celebrated the Quad Partnership for Cable Connectivity and Resilience’s successes, including Australia’s Cable Connectivity and Resilience Centre (outlined below), Japan’s provision of technical assistance in the Pacific, and the United States’ CABLES Program (outlined below) achievements.Footnote ²³² The declaration noted plans to connect all Pacific Island nations with cable networks and that since the previous Quad Leaders’ Summit, US$140 million in cable network funding had been committed. The declaration noted that the leaders ‘underscore our commitment to an inclusive, open, sustainable, fair, safe, reliable and secure digital future’.Footnote ²³³

Several days later on 25 September 2024, a US-proposed statement titled ‘The New York Joint Statement on the Security and Resilience of Undersea Cables in a Globally Digitalized World’ was endorsed by Quad members, the UK and the EU, as well as Canada, the Federated States of Micronesia, Finland, France, the Marshall Islands, the Netherlands, New Zealand, Portugal, the Republic of Korea, Singapore, Tonga and Tuvalu. The ‘New York Statement’ acknowledged the criticality of submarine cable networks and society’s corresponding dependency and vulnerability. Endorsers agreed to a range of principles including resilient and redundant design, use of ‘secure and verifiable’ suppliers with clear governance and ownership structures, close industry and government coordination, better spatial and route planning, best practice sharing, third-country influence risk assessments, data risk mitigation frameworks and, finally, adherence to international law.Footnote ²³⁴ Of note, the New York Declaration articulated how submarine cable networks regard not only the length of submerged cable but are also part of a broader ecosystem, which includes elements related to ‘construction, operation, surveillance, maintenance and repair, such as landing stations, software, and the terrestrial parts of the submarine cable connecting to them, repair centers, as well as the fleet of deployment, maintenance and repair vessels’.Footnote ²³⁵

Announced in late 2024 were plans to create a ‘Quad Action Plan to Protect Commercial Undersea Telecommunications Cables’, although at the time of writing this action plan has not yet materialised. The Trump Administration’s approach to the Quad remains to be fully determined, though the grouping has continued to engage and the administration has not signalled an intention to abandon it.

4.4 United States

The United States deploys several strategies to further submarine cable networks in its national interest. This section overviews US strategy concerning cable security and its ‘Team Telecom’ before examining the US’ efforts at a cable repair fleet and its diplomatic efforts including the CABLES Program. At the time of writing, the impact of the Trump Administration on cable security policy issues is unclear. As is clear, the United States is a key player in subsea communications, and since 2018 has dramatically increased its efforts primarily at nullifying China’s efforts at increased market capitalisation and also at cable flow resilience.

4.5 Australia

While a middle power in Indo-Pacific strategic affairs, Australia plays an active role in submarine cable network security in this new geopolitically charged environment. Indeed, for several decades Australia has enforced submarine cable ‘protection zones’ off its western and eastern coasts. Although legislative improvements could be made, these zones, which criminalise a range of actions which damage or could foul submarine cable networks,Footnote ²⁶⁵ are nevertheless viewed as an international ‘gold standard’ and a legislative model which other states could adapt and adopt. As these protection zones were enacted primarily to deter accidental and negligent seafaring practices – rather than to respond to seabed warfare and geopolitical competition – this section will instead focus on Australia’s Cable Connectivity and Resilience Centre as well as its ‘Australian Infrastructure Financing Facility for the Pacific (AIFFP)’ – both established to thwart China’s forays into the submarine cable market and promote Internet connectivity in line with Australia’s security interests. Indeed, according to its ‘2023–2030 Australian Cyber Security Strategy’, connectivity and cyber resilience in the Indo-Pacific can be consolidated through submarine cable infrastructure investments.Footnote ²⁶⁶

4.5.1 Australian Infrastructure Financing Facility for the Pacific

The Australian Infrastructure Financing Facility for the Pacific, part of Australia’s Department of Foreign Affairs and Trade, was announced in November 2018 and operational in July 2019. The AIFFP partners with Indo-Pacific states and private entities to invest in a range of infrastructure across the Pacific (plus Timor-Leste), including energy, water, transport and telecommunications. According to the AIFFP, the facility designs and delivers ‘high impact, safeguarded projects’,Footnote ²⁶⁷ which has included a range of submarine cable network infrastructure.

The AIFFP was established in tumultuous times and was an initiative implemented under Australia’s ‘Pacific Step-up’ – in part a response to Beijing’s increasing influence amongst Pacific island nations. Identified in Australia’s 2017 Foreign Policy White Paper, support for Pacific island nations was prioritised, as Australian foreign policy officials admitted that ‘like all great powers, China will seek to influence the [Indo-Pacific] region to suit its own interests’.Footnote ²⁶⁸ In 2018, Australia’s then foreign minister Julie Bishop claimed that China was engaging in ‘dept trap diplomacy’, whereby Pacific island states were being ‘trapped into unsustainable debt outcomes’, adding that the ‘trap can then be a debt-for-equity swap and they have lost their sovereignty’.Footnote ²⁶⁹

Since its inception and with a budget of AU$2 billion, the AIFFP has been Australia’s vehicle for cable infrastructure financing, via both grants and loans. Of the 20 projects listed online at the time of writing in 2026Footnote ²⁷⁰ as either ‘completed’ or ‘signed and announced’, six pertain to submarine cable network infrastructure projects (see Table 1). As Table 1 illustrates, Australia’s projects avoid Chinese suppliers, favouring American, Japanese and Australian firms. It also demonstrates the collaborative nature of Australia’s submarine network investments, including Quad nations, as well as New Zealand and Taiwan in some instances.

Table 1AIFFP submarine cable network infrastructure projects.

Table 1 long description.

Table 1 Long description

Data mentioned is as follows. The table contains columns labelled Project, Countries connected, Delivery partners, Supplier, and AIFFP contribution. It summarises submarine cable network infrastructure projects supported through the Australian Infrastructure Financing Facility for the Pacific (AIFFP).

Adamasia Cable System 1 connects the Solomon Islands. Delivery partner: Solomon Islands Submarine Cable Company Limited. Supplier: SubCom. AIFFP contribution: AUD$104 million.

Timor-Leste South Submarine Cable connects Timor-Leste. Delivery partner: Government of Timor-Leste. Supplier: Vocus Group. AIFFP contribution: AUD$7.2 million.

Palau ECHO Submarine Cable Branch System connects Palau. Delivery partners: Belau Submarine Cable Corporation, National Government of Palau, Government of Japan, and Government of the United States. Supplier: NEC. AIFFP contribution: AUD$14.8 million.

Tonga Hawaiki Submarine Cable Branch System connects Tonga. Delivery partners: Government of the Kingdom of Tonga, Government of New Zealand, and Tonga Cable Limited. Supplier: SubCom. AIFFP contribution: AUD$35.6 million.

East Micronesia Cable System connects the Federated States of Micronesia, Nauru, and Kiribati. Delivery partners: Government of the Federated States of Micronesia, Government of the Republic of Nauru, Government of the Republic of Kiribati, Government of Japan, Government of the United States Government, FSM Telecommunications Cable Corporation, BwebwerikiNET Limited of Kiribati, Nauru Fibre Cable Corporation, and NEC Corporation. Supplier: NEC. AIFFP contribution: AUD$65 million.

Hawaiki Nui and Google Regional Submarine Cable Branching Units connect unspecified locations. Delivery partners not specified. Supplier: BW Digital. AIFFP contribution not specified.

Tuvalu Vaka Cable connects Tuvalu. Delivery partners: Government of Tuvalu, Tuvalu Telecommunications Corporation, Google, Government of Japan, Government of New Zealand, Government of Taiwan, and Government of the United States. Supplier: SubCom. AIFFP contribution: up to AUD$53 million.

‘Investment Map’, Government, The Australian Infrastructure Financing Facility for the Pacific, 2025, www.aiffp.gov.au/investments.

4.6 Trilateral Partnership for Infrastructure Investment in the Indo-Pacific

Another grouping formed to support submarine cable projects (amongst other infrastructure developments) is the Australia–Japan–United States ‘Trilateral Partnership for Infrastructure Investment in the Indo-Pacific’. This partnership, between the Australian Department of Foreign Affairs and Trade, the United States Overseas Private Investment Corporation (OPIC), and the Japanese Bank for International Cooperation, was announced in July 2018.Footnote ²⁷³ According to the joint statement, the three nations expressed ‘the belief that good investments stem from transparency, open competition, sustainability, adhering to robust global standards, employing the local workforce, and avoiding unsustainable debt burdens’.Footnote ²⁷⁴

The partnership’s first project, announced in October 2020, was the US$30 million Palau spur cable.Footnote ²⁷⁵ The spur was designed to connect Palau to the Meta and Google-owned (NEC built) Echo cable, which will connect Singapore, Jakarta, Guam and California via the Indonesian archipelago, thus avoiding the South China Sea. The Echo Cable is scheduled for completion in the fourth quarter of 2025 and will be Palau’s second submarine cable connection. Other submarine cable projects funded under the partnership include the NEC-supplied East Micronesia Cable System, which will connect Tarawa (Kiribati), Kosrae (Micronesia) and Yaren (Naru) to Pohnpei (Micronesia) – which has an existing link to the SubCom-laid HANTRU1 Cable System that connects to the Pacific Ocean cable hub of Guam.Footnote ²⁷⁶ The East Micronesia Cable System has an estimated cost of AU$135 million and is scheduled for completion late 2025. According to one senior US official commenting on the East Micronesia Cable System, ‘secure and resilient digital connectivity has never been more important’.Footnote ²⁷⁷

In sum, Australia, the United States and Japan have mobilised this new multilateral grouping to tackle regional submarine cable connectivity gaps by subsidising cables in the Pacific Ocean, thereby thwarting China’s attempts at laying networks via HMN Tech.

4.7 Japan

Tokyo has made various unilateral efforts to further submarine cable resilience, regional connectivity and supply chain security in line with its national interests. Industrially, Japan’s NEC is a leading submarine cable network player and has laid over 400,000 kilometres of subsea cable globally, with close ties to the Japanese Government. In 2008, NEC acquired OCC Corporation (Ocean Cable & Communications) which manufactures optical submarine cables domestically in Japan.Footnote ²⁷⁸ This acquisition reportedly took place amid concern within NEC that China’s Huawei would acquire the strategically important Japanese cable manufacturer.Footnote ²⁷⁹ In July 2024 then US Secretary of State Antony Blinken visited NEC’s Tokyo headquarters, where he was briefed on a range of technologies, including submarine cable technologies. Blinken noted to the press that ‘the leading edge work that [NEC] are doing on undersea cables and communications systems … are the future for digital communications’, lauding NEC as a ‘trusted vendor’.Footnote ²⁸⁰ However, according to NEC President and CEO Takayuki Morita in 2025, the Japanese government provides little assistance to NEC amid global competition, noting that ‘we are the only one fighting with no support’.Footnote ²⁸¹ Amid this discontent, in late 2025 reports emerged that Tokyo may support NEC to acquire a cable installation and repair fleet – pending approvals.Footnote ²⁸²

Tokyo has also announced a range of submarine cable network initiatives, but implementation has been patchy. In 2021, Prime Minister Kishida Fumio announced plans to create a subsea ‘Digital Garden City Superhighway’ which would encircle Japan, economically revitalise Japan’s regions and be part of Tokyo’s Digital Garden City Nation vision.Footnote ²⁸³ While this project was expected to be completed by 2025, the originally proposed new submarine cable network is yet to be installed. In addition, in 2022, Tokyo announced it will spend US$440 million to geographically decentralise submarine cable-landing stations and data centres, citing both economic and security justifications.Footnote ²⁸⁴ In early 2025, Nikkei Asia reported that Japanese ministries are planning to support capital investment in subsea networks and subsidise investment in cable laying vessels.Footnote ²⁸⁵ In foreign relations beyond the Indo-Pacific, Tokyo inked an MoU with the European Union on 3 July 2023 to further ‘secure, resilient and sustainable global connectivity’, although the agreement did not commit either side to any specific joint projects.Footnote ²⁸⁶ Japan’s Ministry of Economy, Trade, and Industry in April 2025 announced that submarine cable policy would be integrated into its purview.Footnote ²⁸⁷ Despite intentions, Tokyo’s efforts at intervention in the submarine cable network market have largely focussed on subsidising regional networks, and unilateral cable resiliency efforts have yielded mixed results at the time of writing. Nevertheless, these efforts to date demonstrate Tokyo is motivated to better secure its cable networks, even if implementation has been uneven.

4.8 India

Despite India’s Quad membership, the key South Asian state is currently prioritising its submarine cable security over promoting regional resilience.Footnote ²⁸⁸ New Delhi’s telecommunications regulators are encouraging the nation’s cable operators to invest in a sovereign India-flagged repair capacity, to diversify the geographic spread of cable landing locations and to connect coastal Indian cities (and new data centres) via domestic submarine cable networks.Footnote ²⁸⁹ Despite these policy priorities, India currently lacks any regional strategy for cable connectivity in either the India Ocean or the wider Indo-Pacific and does not currently invest in cable networks for neighbouring nations. According to a September 2024 joint Quad statement, India recently commissioned a feasibility study to assess expanding ‘undersea cable maintenance and repair capabilities in the Indo-Pacific’.Footnote ²⁹⁰

Opportunities exist for India to foster a domestic submarine cable manufacture capacity – whether by encouraging Indian firms or inviting foreign entities to establish factories. Furthermore, at least publicly, India has not articulated how its national security apparatus will respond to the increasing instances of seabed warfare or how India will protect the cable networks beyond its EEZ. According to scholar Jagannath Panda, while India’s key role in the emerging Indo-Pacific security architecture is clear, the country should integrate submarine cable networks into its regional deterrence strategy, especially vis-à-vis China.Footnote ²⁹¹ In comparison to its Quad partners, India is the least active player in submarine cable network intervention and currently focusses its efforts on domestic rather than regional initiatives. Like Japan, despite patchy implementation to date, India’s efforts nevertheless demonstrate that New Delhi is taking the security of its cable networks seriously, working internally through policy options for future implementation.

4.9 Conclusion

This empirical mapping proves systemic yet evolving state competition in the Indo-Pacific to control cable networks. China’s Digital Silk Road is pitted against the more fragmented Western counter-measures, as each side seeks to exclude respective rivals and reduce respective vulnerability by securing a favourable network position. Other initiatives detailed, including Australia’s AIFFP, the US’ Team Telecom and the Trilateral Partnership show how states mobilise diplomatic and financial tools to dictate network topologies. However, various of these efforts remain challenging to implement, such as the US’ Cable Security Fleet, Japan’s resiliency initiatives and India’s repair strategy. This variation may reflect varying state capacities, threat perceptions, and industrial bases – rather than an absence of competitive dynamics. While this section has focussed on major and selected middle powers, smaller Indo-Pacific states are also navigating this competition, whether as increasingly active cable policy actors or as policy takers caught between competing US and Chinese connectivity offers. A fuller treatment of these states’ responses remains an important avenue for future research. Nevertheless, the subsequent fifth section categorises these responses within a nodes-flows-production typology, showing how key Indo-Pacific states compete for structural positions which lessen dependency risk, which simultaneously create conditions which could be weaponised.

5.1 Nodes

In the Indo-Pacific, funding, laying and operating new and existing regional submarine cable networks is a key battleground between the United States and China. I argue that control over regional connectivity is a key state imperative and is driving network competition in the Indo-Pacific. Control is exerted through influencing network geographical contours (including cable routes and landing station locations), through selecting installers and facilitated through new bureaucratic infrastructures. Major Indo-Pacific powers such as the United States, China and India, plus middle powers such as Australia, are relatively sufficiently connected with commercially viable networks and can veto any ‘untrusted’ suppliers which intend to connect respective shores. As such, emphasis is placed by these wealthier nations on intervening in regional connectivity – submarine cable networks that connect regional neighbours. Ultimately, states are sovereign and can decide on the nature and variety of respective connections; however, pressure and subsidies by powerful states can influence network characteristic choices. Immense efforts are being undertaken by great and middle powers to dictate regional connectivity – the network’s nodes.

As this Element has outlined, submarine cable connectivity is vital for economic growth and global competitiveness, for national security, as well as for the functioning of modern digital societies. As demand for bandwidth from states, businesses and societies grows, submarine telecommunication networks provide the only reliable, stable and cost-effective method of data transmission between continents and islands. Despite advances in satellite data transmission capacities, submarine cables remain the backbone of modern information flows. Moreover, cable connectivity is expensive, and new projects require either a strong business case to attract investors or be subsidised/funded through a state (often through a state-owned telecommunications company). Alternatively, submarine cable network projects are funded (to varying degrees) by multilateral institutions, including the World Bank and the Asian Development Bank. Therefore, nodal connectivity refers to efforts by states to influence the contours of new regional cable networks and to influence the choice of suppliers (as distinct from supply chains). In exerting influence over regional connectivity projects, restricting adverse suppliers is usually a high priority and a method of exclusion.

In this context, an underlying motivation behind initiatives like the Digital Silk Road and the Trilateral Partnership for Infrastructure Investment in the Indo-Pacific is to exclude rivals. Exclusionary policies by the United States and its allies are designed to perpetuate the West’s central role in submarine cable networks and to hobble attempts by China to make inroads. Conversely, China’s ambitions in the cable market are designed to dislodge the West’s central position in digital connectivity and build alternative competing networks. Due to the immense costs associated with submarine cable network design, installation and operation, many smaller countries are forced to make a choice between these competing poles, which naturally excludes the losing side from the infrastructure network. Network exclusion diminishes regional influence, which in turn diminishes relative power. Hence, excluding rivals from new subsea networks has considerable strategic implications for both the winners and losers.

Moreover, states are dictating network geographical characteristics, including landing points (such as deciding which states and cities are to be connected) and routing (such as avoiding hostile or unstable zones) which can create or alleviate dependencies. For example, China has effectively locked the South China Sea to non-Chinese subsea fibre projects by enforcing onerous permitting requirements in that region. As a result, various new trans-Pacific cable projects from Singapore to the United States are transiting the Indonesian archipelago rather than the South China Sea. By influencing cable routes, states can pursue strategic connections and exclude rivals. As a result, submarine cable networks help to bolster trade, military or diplomatic ties between a state and states connected to the network.

In order to pursue network centrality in submarine cable nodes, new bureaucratic infrastructures have been established to rapidly respond, intervene and exclude rivals. As the previous section illustrated, a range of new multilateral initiatives and (intra)governmental groupings have been created to better control new network nodes. For example, the United States established its Digital Connectivity and Cybersecurity Partnership, plus the Partnership for Global Infrastructure and Investment in part to establish its strategic position in subsea networks. Likewise, Australia rapidly stood up the Australian Infrastructure Financing Facility for the Pacific in addition to the Cable Connectivity and Resilience Centre to further its influence over regional subsea network connectivity. Moreover, multilateral architecture, including the Trilateral Partnership for Infrastructure Investment in the Indo-Pacific is a Western attempt at maintaining its strategic position in cable networks and excluding alternative Chinese networks. China too has launched its Digital Silk Road in 2015 with a view to enhancing its centrality in subsea networks for strategic reasons. In this new era, states are investing directly or through multilateral arrangements in new regional cable networks.

As a result of this new bureaucratic architecture that has been established since 2015, in several cases new submarine cable network projects are being determined by strategic state investment and subsidies rather than commercial and market dynamics. Moreover, this new bureaucratic architecture is resulting in swifter and more discrete state intervention than was the case in the late 2010s and early 2020s. For example, international diplomatic controversies ensued in 2016 and 2020 when Chinese firms were set to win submarine cable installation contracts in the Solomon Islands, and then Kiribati, Micronesia and Narau, respectively. In both of these cases, Western nations stepped in to thwart Chinese bids, in the process establishing bureaucratic infrastructure which has since been mobilised to subsidise or fund regional cable networks before China can mount a compelling offer. Moreover, these bureaucratic architectures are not being implemented unilaterally but are being coordinated amongst partners for maximum effect. As outlined in an earlier section, the Trilateral Partnership for Infrastructure Investment in the Indo-Pacific combines American, Japanese and Australian state capital to circumvent China’s cable network-laying ambitions and advance collective nodal control amongst like-minded democracies.

By intervening in regional submarine cable network design, states are able to both exert regional influence and promote respective notions of ‘data integrity’. Just as states invest in physical infrastructure in developing states to build influence, centrality in physical submarine cable networks is likewise used as a tool of statecraft and as a source of power. Functioning cable networks can be used as a tool of geopolitical leverage, of economic control, of soft power and of technological standards leadership. For many small islands and less developed states which receive a subsidised or externally funded cable network, continued access to the data conduit is often an existential issue. Concurrently, by intervening in network nodal connectivity, middle and great powers can dictate network security, thereby setting and enforcing rules and standards. Specifically, states can ensure networks avoid hostile states (and associated territories) which could gain physical or digital access to the network or subject the network to undue monitoring. While these network infrastructures may not be otherwise commercially viable, by subsidising or investing in networks directly, powerful states can determine routing decisions to accommodate respective national security imperatives.

As outlined, states are increasingly intervening in new submarine cable network designs to further visions of regional connectivity, according to respective national interests, which can create the conditions for weaponisation. As these connectivity ideals are sometimes not commercially viable, states are increasingly subsidising and investing to better control future network contours. This competition to control the contours of subsea digital connectivity positions states for future possible leverage. Simply put, in this era of heightened geopolitical competition, Indo-Pacific great and middle powers are vexed by the contours of new regional submarine cable networks and how centrality in these networks can be used to further a favourable balance of power.

5.2 Flows

The second imperative driving states to intervene in the global submarine cable ecosystem is flow control – defending the data that transits submarine cable networks from accidental, negligent and intentional incidents. Moreover, flow control can also result in weaponising data flows and exploiting these transmissions for strategic purposes – as Farrell and Newman describe as the ‘panopticon effect’ – which is ‘the ability to glean critical knowledge from information flows’.Footnote ²⁹² The digital interconnectedness afforded by submarine cable networks results in both strategic benefits and also strategic vulnerabilities. Even though the overwhelming majority of cable faults occur due to accidents, negligence and natural phenomena, in this era of heightened geopolitical tensions between China and the United States, the fear of hostile cable incidents and espionage is driving state intervention.

Unlike strategies to intervene in network nodes (as articulated above), Indo-Pacific nations have been slow and/or reluctant to articulate public strategies to defend submarine cable networks. While counterparts in Europe – both nation-states and regional organisations such as NATO and the European Union – have publicised investment into cable protection strategies, states in the Indo-Pacific have thus far been reluctant to likewise articulate defensive plans against hostile actions.Footnote ²⁹³ This reluctance is due to the lack of suspicious seabed incidents which have taken place in the Indo-Pacific, compared with the various high-profile suspicious examples in Europe this Element has detailed. While in late 2025 Australia’s Chief of Navy said publicly that the loss of Australia’s submarine cable networks would be an ‘existential threat’,Footnote ²⁹⁴ the country’s 2024 Civil Maritime Security Strategy does not consider the particulars of seabed critical infrastructure,Footnote ²⁹⁵ and Australia’s 2024 National Defence Strategy likewise does not engage with seabed lines of communication.Footnote ²⁹⁶ Moreover, little is publicly known about the offensive seabed warfare and cable disruption plans of Indo-Pacific nations – information which is a closely guarded secret.

Nevertheless, Indo-Pacific states are pursuing network flow resilience through various softer strategies, including advisory functions and best-practice strategies. For example, the multilaterally endorsed ‘New York Joint Statement on the Security and Resilience of Undersea Cables in a Globally Digitalized World’, as noted above, advocates for submarine cable network design prioritising ‘resilience, redundancy, and security’, in addition to ‘spatial and route planning to promote coordinated use of seabeds, protect cables from natural or man-made hazards, ease chokepoints, and reduce risk of inadvertent disruption while expanding global connectivity’.Footnote ²⁹⁷ Likewise, the United States’ Office of Economic Security, the Supply Chain Resilience Center, and the Cybersecurity and Infrastructure Security Agency collaboratively published a report in 2024 titled ‘Priorities for DHS [Department of Homeland Security] Engagement on Subsea Cable Security & Resilience’, which advocates for better public–private coordination and streamlined permitting, licencing and regulation, in addition to clearer emergency management and incident response arrangements.Footnote ²⁹⁸

Moreover, the International Cable Protection Committee (ICPC), which has an extensive membership primarily consisting of industry players in addition to key governments and public agencies including the governments of Australia and India, plus the US Navy and China Telecommunication Corporation, advocates for effective submarine cable security and resilience amongst governments globally. The ICPC’s flagship ‘Government Best Practices for Cable Protection Resilience’ publication is a guide for public officials to security cable networks, advising best practices across key issues including fishing and anchoring risks, seabed spatial separation, charting, domestic protective legislation frameworks, government points of contact, regulatory ease of repair, critical infrastructure designation and data sharing.Footnote ²⁹⁹ Through joining and supporting the work of the ICPC, these key Indo-Pacific governments and agencies are attempting to further the resilience and security of global subsea connectivity through public policy advocacy.

Exploiting submarine cable flows in the modern era is likewise little understood publicly due to security classification barriers but, nevertheless, drives submarine cable flow policies and explains why states pursue centrality. The Snowden revelations in 2013 laid bare how submarine cable landing stations can be sites of monitoring and signals intelligence collection. Indeed, cable networks presumably remain a key enabler of data interception and signals intelligence collection in the modern era, although details are difficult to ascertain. Securing flows can be understood by the ‘panopticon effect’, which articulates how control of network infrastructure can permit data monitoring. In this sense, China’s efforts at installing an alternate network of submarine cables – via its Digital Silk Road – can be posited as a push to simultaneously escape the West’s panopticon, and perhaps enable its own.

Securing cable flows from disruption is currently the least developed imperative for Indo-Pacific states, unlike for European counterparts. This perceived latency is due to a lack of urgency in the Indo-Pacific to actively defend these networks and hampered by a methodological difficulty to ascertain how militaries are preparing for seabed warfare due to security classification restrictions. We cannot assume that just because Indo-Pacific states do not publicly link undersea warfare capability development with submarine cable protection, that these seabed infrastructures are being neglected by militaries. However, this public sluggishness may be strategic rather than permanent. As future cable incidents occur in the Indo-Pacific, these soft governance mechanisms outlined above may be deemed inadequate, and submarine cable defence may be formalised and publicised.

5.3 Production

The third imperative driving states to intervene in the submarine cable ecosystem is perceived production and supply chain vulnerabilities. As this Element illuminates, supporting sovereign or allied cable network suppliers is a foremost consideration when considering new networks. States can hobble hostile suppliers through sanctions, through onerous permitting requirements, by avoiding particular firms in new projects and by banning cables landing within jurisdictions. In this context, supply chains refer not only to the raw materials and components which make up cable networks but also to repair capacities and sovereign industry capabilities. Assured access to cable network materials, components, expertise and repair capabilities is fundamental in driving resilience and connectivity, as outlined above.

Submarine cable networks consist of many materials and components. The average length of cable alone consists of a range of materials, including (from outside in) tar-soaked nylon yarn, galvanised armour wires, nylon yarn bedding, polyethylene insulator, copper sheath, ultra-high strength steel wires, buffering material (plastic/steel) and silicone gel, before ultimately the optical fibres.Footnote ³⁰⁰ Most cables are also powered to operate underwater repeaters, utilise branching units and Reconfigurable Optical Add/Drop Multiplexers, and landing stations require a range of specialised equipment. The origin and sources of these materials and components are being increasingly scrutinised. States are increasingly aware of these supply chain issues to ensure availability in a crisis. Fears over inbuilt backdoors and compromised equipment also drive supply chain scrutiny. As submarine cable networks have been key sites of signals intelligence collection and espionage, concerns over technically compromised equipment abound.

States’ fears of being strategically dependent on others for these key components and materials are driving policy responses and intervention. By extension, many major and middle powers are attempting to onshore or ‘friendshore’ submarine cable manufacture and operation capabilities or support existing sovereign industry.Footnote ³⁰¹ American efforts at obstructing China’s submarine cable industry are evidenced through its addition of Huawei Marine Networks in 2020 to the ‘entity list’, resulting in its divestment from Huawei and phoenixing as HMN Tech under a new parent company.Footnote ³⁰² After the United States successfully thwarted HMN Tech’s bid to install the intercontinental SeaMeWe-6 cable network, China’s foreign ministry issued a statement noting that the United States ‘should stop fabricating and spreading rumours about so-called “data surveillance activities” and stop slandering and smearing Chinese companies’.Footnote ³⁰³

Sovereign cable repair capacity has become an issue of interest and action amongst Indo-Pacific states. While cable resilience in peacetime is largely managed by the private sector, conflict would entail a new set of considerations. As this Element has illuminated, during conflict submarine cable networks and associated installation and repair vessels become a target as maintaining network uptime is paramount. Ensuring submarine cable network resilience during a conflict would take a coordinated approach from military assets, coastguard vessels, cybersecurity specialists, the cable industry and policy coordination departments. Militaries and coast guards would be required to defend not only military seabed infrastructure but also civilian telecommunications cables, which would likewise be targeted during a confrontation. As submarine cable networks have not been targeted in a full-scale conflict since the Second World War (when telegraph cables were linking the globe), how optical fibre cables would be targeted (e.g. kinetically or virtually) and affect the outcome of a war is uncertain. However, in today’s digitally interconnected society, targeting submarine cable networks during a conflict would have devastating ramifications for the populations and communities affected. During a conflict, whereby flows of goods and services are interrupted and cables are targets, a sovereign cable industry would be a vital component of national power. From an American perspective, analysts Daniel F. Runde, Erin L. Murphy and Thomas Bryja argue that ‘the overreliance on Chinese [cable] repair ships due to limited alternatives in the marketplace is another vulnerability if, during a time of military conflict, the Chinese government prohibits access to its repair ships’.Footnote ³⁰⁴

Submarine cable repairs are generally coordinated and undertaken through cable maintenance zone agreements, which pool cable repair ships within specified maritime areas or individual maintenance contracts. While these agreements have operated largely successfully for many years, many states are increasingly concerned about the availability of these vessels in a crisis and a state’s inability to dictate repair priorities. While submarine cable repair hubs (docks and depots) and repair ship flags have been decided by commercial factors, geopolitical factors are changing the geography of these repair infrastructures. States are increasingly attempting to intervene in submarine cable repair arrangements in order to dictate repair prioritisation, such as the (now defunded) United States Cable Security Fleet, China’s involvement in S.B. Submarine Systems and India’s feasibility studies into sovereign repair fleets. Also, by controlling cable repair infrastructures, these services can be shared with partners and be used as a tool of statecraft while also mitigating the possibility that cable engineers interfere with submarine cables while undertaking repairs or introduce backdoors or otherwise compromise the networks.

By supporting the production of sovereign and/or friendly submarine cable network supply chains, these firms can be instrumentalised by states and be incorporated as an element of statecraft – the possible limitations of which are engaged with in Section 6. Due to the close relations these firms have with respective governments – including financial – an alignment with national security objectives is expected. As a result, states could leverage respective firms to further national security objectives and implement defence and foreign policy agendas with geopolitical implications. As a result, there emerges a blurring between the commercial and security logics which drive submarine cable network design and maintenance. While in the post–Cold War era cable networks were largely driven by commercial considerations, geopolitical factors are increasingly dictating network dynamics, including supply chains and industry considerations. In sum, submarine cable supply chains, whether they be materials or components, the cable industry or repair capabilities, are being increasingly scrutinised by states seeking greater control. By controlling the supply, states can ensure sovereign oversight of these critical infrastructures and improve connectivity on respective terms, simultaneously furthering geopolitical goals of attaining or maintaining network centrality.

5.4 Conclusion

In the Indo-Pacific, efforts at network centrality are driving state intervention into submarine cable network nodal control, flow rule and production dominance. Indo-Pacific states have made considerable efforts to control network nodes through subsidies and bureaucratic infrastructure – evidenced by China’s Digital Silk Road and Western competing initiatives. These initiatives secure network positions that reduce vulnerability to adversary control. In contrast, efforts at controlling flows have remained relatively mild in the Indo-Pacific, as states focus on softer governance and advisory resilience initiatives to date, rather than military responses (at least articulated publicly). Despite this, the panopticon effect, and ability to monitor data traffic, does explain the value in, and efforts to, control network flows. Controlling production is a significant line of effort amongst Indo-Pacific states, which can blur the line dividing security and commercial logics. This analysis demonstrates how states in the Indo-Pacific compete for network centrality to mitigate vulnerabilities, though structural competition creates conditions that risk weaponisation – echoing Farrell and Newman’s warning. However, limitations to this weaponisation possibility exist, which are engaged in the following concluding section.