Securing the Deep: Business Opportunities in Subsea Defense

As global reliance on subsea infrastructure grows, so do the risks. Discover how safeguarding undersea assets opens new frontiers for innovation and investment.

Importance of Subsea Infrastructure

Subsea infrastructure plays a critical role in maintaining the operational continuity of the modern society and the global economy. This vast network includes subsea data and communication cables, pipelines for energy transportation, electricity cables, and resource extraction systems. What’s important is that these components are increasingly vulnerable to damage, whether due to natural phenomena or intentional human interference.

In the realm of communications, submarine cables are indispensable:

• They carry between 97% to 99% of global internet traffic, underpinning everything from everyday civilian internet usage to critical financial transactions and military communications (Defense News, 2020; TeleGeography, 2024).
• Cable traffic represents about $10 trillion in daily financial transactions. (Defense News, 2020)
• With over 570 submarine data and communication cables currently in use, stretching across more than 14 million kilometers and connecting over 1,300 landing stations globally, these cables form the backbone of our global connectivity (Military Law Review, 2021; TeleGeography, 2024).
• As of June 2024, this number has grown to include more than 600 active and planned submarine cables, emphasizing their continued expansion and importance (TeleGeography, 2024).

Beyond communication, the seabed also supports extensive energy infrastructure, including gas pipelines and electricity cables. For example, the North Sea alone hosts approximately 3,000 kilometers of gas pipelines alongside numerous cables1. As climate change accelerates the shift to renewable energy, the importance of undersea infrastructure has significantly increased. While some traditional oil and gas pipelines may decline in number, there are initiatives to repurpose these structures for new applications, such as transporting hydrogen or enabling carbon capture and storage. Additionally, electricity cables interconnect power markets, allowing for electricity transfer to balance supply and demand across regions and between islands and the mainland, thus supporting the integration of variable renewable energy sources. The growth of offshore wind power, for instance, requires more seabed electricity cables to connect new wind farms to the grid.

Aside from civilian uses, underwater cables are vital for military operations. Most military communications, including those necessary for operating remote drones in distant theaters, are transmitted through the transatlantic and transpacific cable networks. These cables also facilitate secure military-encrypted and diplomatic communications, underscoring their strategic importance (Wilson Center, Polar Institute, 2024).

In today's competitive and threat-laden environment, the vulnerabilities of our expanding subsea data and energy transportation systems—responsible for transferring molecules and electrons—are increasingly exposed. This highlights the critical importance of subsea defense.

Vulnerabilities and Attack Vectors

Subsea infrastructure, while critical, is fraught with vulnerabilities that pose significant risks to global security and economic stability.

Physical Vulnerabilities

Subsea security and seabed warfare have become prominent issues in the context of gray zone operations and sub-threshold warfare against critical underwater infrastructure (CUI). For hostile state actors, disrupting CUI is an attractive strategy due to its low-cost, high-impact potential, driven by critical dependencies and the cascading effects disruptions can have (Wilson Center, Polar Institute, 2024). Among CUI, fiber optic data and communication cables are particularly susceptible to disruption. The Arctic region exemplifies this vulnerability due to its geographic and natural chokepoints, like the Svalbard, Greenland–Iceland–UK (GIUK), and Greenland–Iceland–Norway (GIN) gaps and the Bering Strait, where cable resilience is minimal. This lack of redundancy, along with increasing geopolitical importance of the Arctic, makes cables in the region prime targets for seabed warfare (Wilson Center, Polar Institute, 2024).

While, in most places, cables are widespread across the ocean floor, reducing bottleneck risks, their landing stations can become focal points for potential attacks due to their geographical concentration (Kavanagh, 2023). Coordinated attacks on critical nodes could cause cascading failures, significantly affecting systems and escalating costs, with broader economic and societal repercussions (Rand, 2024).

Practically speaking, in deeper waters, cables lie unprotected on the seabed, making them less vulnerable to anchoring or trawling but more susceptible to deliberate sabotage. Additionally, the public availability of detailed maps displaying cable locations increases their exposure to malicious acts (TeleGeography).

Attack Vectors

One of the key vulnerabilities of subsea infrastructure lies in its geographical isolation. The lack of an immediate human presence at these sites makes physical threats, such as attacks on fiber optic and copper cables, relatively easy to execute (Turing Institute, CETAS). This remoteness also results in longer response times for security services, further compounding the risk.

The rise of autonomous underwater vehicles (AUVs) and drones has introduced a new dimension of threats. These technologies can be exploited for hostile surveillance or direct attacks. Additionally, as drone-based operations and maintenance (O&M) become more common, the risk of hacking or malware implantation during production grows. Such vulnerabilities could allow malicious actors to manipulate drones once they are operational (The Diplomat, 2023). These advancements not only enhance the capabilities of state actors but also extend sophisticated tools to terrorist organizations and criminal networks, broadening the scope of potential threats.

The subsea cable industry also faces critical supply chain risks. China's rapid emergence as a leading subsea cable supplier, driven by its Digital Silk Road initiative, has positioned it to capture a significant share of the global fiber-optic market. Companies like HMN Technologies, which supplied up to 18% of subsea cables between in 2019-2023, play a major role in expanding global cable infrastructure (Reuters, 2023a). However, this dominance raises national security concerns, particularly among NATO members (CSIS, 2024). Firmware and software used in cable landing stations could be compromised before installation, with adversaries potentially embedding bugs or surveillance devices in hardware. Once breached, attackers could manipulate cable controls or disrupt operations.

While a single attack on subsea infrastructure might cause limited disruption, coordinated assaults could trigger devastating cascading effects—potentially serving as precursors to larger military actions or coercive strategies. Protecting this critical infrastructure is essential, requiring robust surveillance measures and international collaboration to address these growing vulnerabilities.

Recent Examples of Threats

In recent years, several incidents have highlighted the vulnerabilities of subsea infrastructure. In 2023, Taiwanese authorities accused Chinese vessels of cutting submarine cables that are critical for internet connectivity to Taiwan’s Matsu Islands (CSIS, 2024). The incident left 14,000 residents in digital isolation for six weeks.

In the Baltic Sea, a telecom cable linking Sweden and Estonia was damaged alongside a Finnish-Estonian pipeline and cable in October 2023, with investigations pointing to Russian and Chinese vessels as potential saboteurs (Reuters, 2023b). Further incidents in November 2024 saw communication cables between Sweden and Lithuania, and Germany and Finland severed, raising suspicions of sabotage (Guardian, 2024).

Globally, the South China Sea and the Red Sea have been identified as chokepoints for undersea cables. In March 2024, several major cables in the Red Sea were cut, impacting 25% of data traffic between Asia and Europe (Rand, 2024).

These threats are not just isolated incidents but may form part of broader strategic maneuvers. At the onset of potential hostilities, cable disruptions can serve as tactical enablers, preparing the battlespace for larger military operations. Such disruptions often occur alongside coordinated activities, marking the "first salvo" in broader conflict strategies (Wilson Center, Polar Institute, 2024).

Threats to Subsea Infrastructure

Subsea infrastructure is increasingly threatened by activities that fall within the realm of plausibly deniable, sub-threshold operations. These threats are often carried out by state and non-state actors using dedicated units, structures, and subsurface capabilities.

There are two primary categories of seabed warfare activities that adversaries might conduct against underwater cables: intelligence gathering and physical destruction.

• Intelligence Gathering

This involves mapping and monitoring seabed infrastructure, primarily conducted by civilian vessels and uncrewed underwater vehicles equipped with remote-sensing capabilities (Wilson Center, Polar Institute, 2024). Such operations allow actors to prepare for potential acts of sabotage and gain awareness of the cable layout. The physical tapping of cables to intercept communications, although technically challenging, is another form of intelligence gathering.

• Physical Destruction

This more direct form of attack involves severing cables or using undersea explosives like torpedoes or maritime improvised explosive devices (MIEDs) to damage or destroy them (Wilson Center, Polar Institute, 2024). Such actions can be disguised as accidental, using "ghost ships" to conduct anchoring and dredging activities.