At the same time, underwater cables bring with them major political and security downsides that undermine national security and sovereignty.
In particular, they have the potential to embroil smaller states in regional conflicts and place them in the middle of superpower rivalries. We were reminded of this in recent weeks, when Iran responded to speculation that the US intended to restart the war by threatening to attack underwater cables in the Gulf maritime domain.
Ambitious states host underwater cables for reputational, as well as economic, opportunities. In these terms, underwater cables serve as a strategic instrument at the nexus of national economic planning and national security.
For example, approximately three-quarters of all cables in the northern hemisphere pass through or near Irish waters, with four transatlantic cables directly connecting with Ireland. This makes Ireland’s underwater infrastructure strategically important within the transatlantic security ecosystem.
Singapore provides a similar example in a different region. It has more data cables landing on its territory than any other country in Southeast Asia. This provides an opportunity for it to use underwater cables to transform its historical status as a strategic port city between the Straits of Malacca and the South China Sea, into a digital hub and transit station for cables. In contrast with other regional countries such as Vietnam and China, which restrict cross-border data flows and shore up their data regulation regimes, Singapore promotes a cross-border data policy in line with its goal of becoming a major "free data port”.
States that serve as regional gateways for underwater cables, like Ireland and Singapore, explain their role in cable infrastructure solely in economic terms. But they are also unavoidably caught up in a complex web of tech geopolitics.
Firstly, states that host underwater cables and the high-value strategic data they carry have become implicated in wider debates over data sovereignty and, specifically, attempts by other states and non-state actors to gain extra-territorial access to data.
On top of this, governments that host underwater cables also have to deal with the security and state sovereignty implications of the fact that 98% of the world’s underwater cables are manufactured and installed by only four privately-owned companies (one each from the US, France, Japan and China). This challenge is compounded by the fact that major cloud and tech companies including Google, Meta, Microsoft, and Amazon now own or lease roughly half of all global underwater cable capacity to support their cloud infrastructure.
This underwater cable network is also increasingly vulnerable to sabotage and hybrid warfare attacks. In Europe in recent years, telecommunications cables between Sweden and Estonia, Finland and Estonia, Lithuania and Sweden, and Finland and Germany have been sabotaged. In the Red Sea, recent attacks have damaged cables connecting respectively Africa, Asia and Europe, Southeast Asia, the Middle East and Western Europe, and India, the Middle East and Western Europe.
In response, Nato has made seabed defence an increasingly important priority, launching several initiatives to map underwater vulnerabilities and track potential hybrid attacks. These include the Critical Undersea Infrastructure Coordination Cell and the Maritime Centre for the Security of Critical Undersea Infrastructure. Actors in other regions are doing the same, developing their own security responses to this rising threat on the national and regional levels.
No less challenging, certainly over the longer term, is the relentless tech rivalry between the US and China, both of whom view underwater connectivity as a national security issue and a central aspect of great power politics. In its home region, Beijing uses its extensive network of state-firms, including China Telecom, and its influence over private companies like HMN Tech (formerly Huawei Marine) to consolidate control of cables.
This is very evident in the contested waterways of the South China Sea, where China, Vietnam and the Philippines compete over sovereignty. Further afield, in order to bypass traditional Western-dominated digital hubs, China routes data traffic, including its 15,000km fibre-optic network PEACE cable, which stands for Pakistan & East Africa Connecting Europe, through Chinese-controlled or friendly locations including Gwadar Port in Pakistan.
For its part, the US has moved to protect strategic cables by implementing a range of policies and laws, including the Undersea Cable Control Act that tighten restrictions on investment and landing rights. Beyond its home region, Washington is working with regional allies, including Japan and Australia in Asia-Pacific, to develop cable routes that sideline Chinese access and influence and that reduce the number of Chinese landing sites in direct trans-Pacific and Asia-Europe cables.
For example, a Chinese vendor working on the Coral Sea cable linking Sydney, Papua New Guinea, and the Solomon Islands was replaced by French and Australian firms. Similarly, Chinese bids were rejected in favour of Japanese firms in a major project to integrate Pacific Island nations into secure data networks.
Underwater cables will continue to make a vital contribution to modern communications and economic growth. There will also be no shortage of states looking to become involved in the routing of global flows of capital and information via undersea cables. This will be true even as supporting and hosting the underwater cable eco-system increases a state’s vulnerability to the whims of great power politics and hostile hybrid attacks and disruption.
- The writer is professor of International Politics and director of the Small States and Energy Studies Programs at Georgetown Univeristy in Qatar@RoryDavidMiller