The subsea cable sector has undergone a significant transformation with growing investments from big tech firms. In the first of a series of reports, we detail the changes in cable ownership and manufacturing and consider concerns with cable resilience in this context.
While the modern geography of subsea cable routes still mirrors the maps of colonial-era telegraph systems, a change is emerging in who manufactures and owns this critical infrastructure. US tech firms have now come to account for an increasing proportion of subsea cable investment. Since 2018, the proportion of new cable length owned solely by tech firms has increased from 17,000km to over 62,000km (+300%).
Subsea cable manufacturing has a long history in nationally-aligned interests, and a handful of firms closely tied to their national governments control the market. SubCom of the US, ASN of France, NEC of Japan and HMN Tech of China will have supplied all but 3% of new cable length between 2018-2026.
The differing interests of telecoms operators and tech firms in deploying subsea cables is beginning to demonstrate a divergence from national interests in cable routing which will only grow as older, telecoms-backed cables are increasingly retired. However, the cable manufacturing market remains largely reflective of regional political alignments.
Anxieties around foreign espionage, sabotage and economic dependency in relation to subsea infrastructure have existed since the earliest days of the telegraph-based network. However, recent interference with subsea cables (both accidental and wilful) has heightened governmental concerns around the security and resilience of the network and inspired new regulatory intervention.
Subsea cable infrastructure sets centuries-old geography against modern connectivity needs
Though modern communications networks are often defined by their evolution, the backbone of contemporary connectivity reflects an older and more consistent history. Dating to the development of global telegraph networks in the 19th century, the maps of modern subsea communications cable infrastructure still reflect many of the strategic connections of the colonial world order. Despite this deep history of geography, the changing landscape of global connectivity has nonetheless influenced the subsea cable sector. With the exponential growth of global data traffic and the rise of big tech firms in controlling increasingly important layers within the network stack, shifts in subsea cable ownership structures mirror broader shifts in how countries, and ultimately consumers, get and stay connected. Recognising the increasing attention paid to subsea infrastructure by firms and governments alike, we contextualise these changes and describe the threats facing the system more broadly.
From the 19th century beginnings of subsea cable history through much of the 20th century, both the ownership and the manufacturing of the underwater infrastructure was led by governments and state-owned entities. Unsurprisingly, the liberalisation of communications markets in the latter half of the 20th century also saw newly privatised operators take over the work of developing and maintaining subsea connectivity for the countries in which they operated. Operators typically form ownership consortiums, joining with up to dozens of firms to collectively fund and buy capacity from a given cable project. These ownership groups often represent their jurisdiction’s national connectivity interests through close coordination with governments as critical infrastructure providers. The TAT-8 cable, the first transatlantic fibre-optic cable, was launched in 1988 and led by AT&T, BT, and France Telecom in service of the strategic interests of the US, UK and French governments alongside dozens of other consortium members.
Investments from big tech firms account for increasing proportions of new subsea cable construction
Since Google made its first investment as a part owner of the Unity cable in 2010, the share of cables partly owned by big tech firms has continued to grow steadily (see Figure 1). Though it took almost another decade for Google to launch its first solely owned cable project in 2018 – the Junior cable in Brazil – the proportion of new cable length owned privately by Amazon, Google, Meta and Microsoft has since increased nearly 300%. From 2018 to 2021, Google and Meta combined to privately own approximately 17,000km of total new cable. That figure has grown to over 67,000km in new cable ready for service between 2022 and 2025. This length also does not account for projects such as the Pacific Light Cable Network (PLCN) in 2022 or the Echo cable expected in 2025, which total nearly 30,000km in new cable jointly owned by Meta and Google. Comparatively, this period saw a 110% increase in new cable partly owned by tech firms and a 50% increase in new cable owned by telecoms operators or other sectors, including direct investments by governments. 2023 represented the first year in which more cable solely owned by tech firms came online than cable owned by telecoms firms and other sectors.
The market for subsea cable manufacturing reflects national interests amid rising global tensions
Similar to the market for investment in and deployment of subsea cables, the market for the manufacturing of subsea cable infrastructure has changed substantially. Though manufacturing of subsea cables has long been a pursuit backed by the strategic political interests of governments, dating to the British Gutta Percha Company of the colonial era, the rise and fall of contemporary manufacturers now reflect modern political allegiances. Today, SubCom of the US, Alcatel Submarine Networks (ASN) of France, NEC of Japan and HMN Tech (formerly Huawei Marine) of China dominate the cable manufacturing sector (see Figure 2). All other cable suppliers only accounted for about 3% of the new cable planned between 2018 and 2026.
While Huawei and other Chinese vendors were able to make greater gains in other parts of the connectivity sector, including fixed and mobile network infrastructure, the spread of HMN Tech has been more geographically limited, having supplied only one connection each to the US and EU since 2018. The firm has been responsible instead for a significant proportion of the cable run through China, Southeast Asia, Africa and Latin America. Similarly, SubCom has been the largest supplier of cable connections to the US during that period and the largest cable supplier for projects partly or solely owned by American big tech firms. The US manufacturer accounts for nearly 130,000km of Google’s approximately 196,000km cable portfolio and just over half of all of the cable lengths partially or completely owned by big tech firms. Notably, HMN Tech has never been the supplier for a big tech-backed cable project, although Google, Meta and Microsoft have all joined ownership coalitions with Chinese operators China Mobile, China Telecom and China Unicom.
The interests of cable owners and national governments have been realigned in the past decade
To some extent, these changes in the subsea cables sector have shifted the alignment of cable owner interests and national interests. In the context of cable deployment, telecoms-led coalitions have tended to continue old patterns of connecting countries and communities in which they operate. Though routing global data traffic is necessary to operators’ business, the growth of localised, as opposed to global, data demands has resulted in a greater priority on more cable projects that cover fewer kilometres but connect to more, centrally located landing stations. The importance of resilience to communications services for more populated areas means these coalitions are also apt to build or maintain redundant routes between countries. Comparatively, the interest of big tech firms in connecting their global assets, such as data centres, is generally reflected in longer routes with fewer landing sites that are not necessarily adjacent to more populated regions (see Figure 3). This divergence between tech and telecoms priority routes will become increasingly relevant as older, telecoms-funded cable is increasingly retired.
The interests and actions of big tech firms’ have not diverged entirely from those of governments, however. Some forthcoming cable projects, particularly those owned by Google, reflect the strategic interests of the US Government, such as the Pacific Connect initiative and Google’s plans to build out US connections to Southeast Asia. The US Government, through the Department of State and its Bureau of Cyberspace and Digital Policy, has also actively promoted the cable investing activities of Google and Meta. However, the influence of national governments is more evident in the relationships between cable owners and the vendors with which they contract. In addition to SubCom’s dominance among big tech backed cable projects, ASN accounts for approximately 60% of all the cable laid since 2010 that connects to a European country. Similarly, just under 90% of the cable laid by NEC since 2010 has connected through the Pacific region. This regional dominance undoubtedly reflects the historic linkages between manufacturing firms and national governments and suggests that de facto vendor restrictions in cable supply may already exist.
The threats facing the subsea cable system are not new, but rather heightened
As with other elements of the global network stack, concerns with the stability of supply chains and the critical nature of connectivity have driven governments and regulators to pay increasing attention to network resilience. However, the challenges uniquely associated with subsea cable infrastructure – including limited redundancy, lack of effective enforcement for criminal tampering and the existing linkages between hostile nations – long predate this contemporary anxiety. The first effort to protect global subsea infrastructure dates back to 1884 with the signing of the Convention for the Protection of Submarine Telegraph Cables (the Paris Convention) which criminalised willful or negligent harm to subsea telegraph cables. Nonetheless, the same fears of espionage, sabotage and economic dependency, which have characterised modern discourse around subsea cable systems, have persisted through the history of global connectivity.
In some regard, these concerns about foreign interference with cable systems are not unfounded, even though the vast majority of cable damage is accidental. In 1971, Operation Ivy Bells launched the US Government’s decades-long successful tap of a USSR subsea cable. More recently, documents leaked by Edward Snowden in 2013 revealed that the UK and US government had successfully tapped as many as 60 international subsea cables, including major systems such as the FLAG cable which circumnavigates the globe. Additionally, a more recent incident in 2023 in the Baltic Sea resulted in the severing of communications and gas lines running between Estonia, Finland and Sweden. The Finnish and Swedish governments have alleged the damage was the result of potentially malicious actions by Chinese-owned and Russian-owned container ships. Much more common, however, is unintended damage to cable routes such as recent incidents involving the South East Asia–Middle East–Western Europe (SeaMeWe) corridor and lines along the western coast of Africa which all resulted in large scale connectivity outages. Recognizing that subsea networks carry between 95% and 99% of all global data traffic, governments have rightfully expressed concerns over accidental cable damage as well as the worst-case-scenario of malicious cable sabotage. Both would threaten critical connectivity infrastructure on a large scale, driving policymakers to attempt to regulate the famously lawless context of international waters.
