Publication Details

27 November 2024

Introduction

Critical underwater infrastructure (CUI) is vital to several day-to-day functions in contemporary societies and economies. Undersea fiber-optic cables, electricity cables, and pipelines are essential cogs in the global data and energy supply chain’s architecture. Extensive CUI networks have turned the ocean floors into congested maritime spaces where power, oil, gas, and digital information travel across vast transoceanic distances. Considered a secure and efficient mobility solution to transport physical and digital commodities, CUI is poised to play a pivotal role in sustaining the global economy’s growth.[1] However, lying on the ocean floor, mostly invisible to its final beneficiaries and end-users, CUI protection has long been overlooked in the public security debate.[2] The intensification of sabotage acts and unintentional accidents damaging CUI have underscored to what extent essential societal activities depend on CUI.

Defining “Criticality”

The long-term prosperity and growth of contemporary economies and societies are predicated on effective CUI security. However, clearly defining what makes an infrastructure “critical” is a complex endeavor that requires careful consideration and debate.

Confronted with the urgency to design contingency plans to counter transnational terrorism threats in the 2000s, the European Union (EU) and the U.S. Department of Homeland Security have offered some solutions. Brussels classified a critical infrastructure as “an asset, system, or part thereof […], which is essential for the maintenance of vital societal functions, health, safety, security, economic or well-being of people.”[3] The U.S. defined it as “systems and assets, whether physical or virtual, so vital […] that the incapacitation or destruction of such systems and assets would have a debilitating impact on national security, national economic security, public health or safety, or any combination of those matters.”[4]

The concept of “critical infrastructure” primarily depends on the perception that the beholder, either public or private, has of an asset. Therefore, denominating an asset as “critical” mainly results from political choice.[5] Nevertheless, discretional considerations aside, infrastructure can be considered “critical” when its disruption triggers adverse ripple effects that severely hinder the ordinary functioning of assets in other sectors. In other words, the interdependency among different assets appears crucial in making “critical” an asset.

Navigating in the “Age of Ocean Infrastructures”

Over the past decades, the considerable intensification of anthropogenic activities in the maritime space – understood as human activities having adverse impacts on the environment, such as fishing, maritime shipping, and deep-seabed exploitation – has significantly contributed to the development of a dense web of offshore infrastructures at the national, regional, and global levels, inaugurating what Christian Bueger, Professor of International Relations at the University of Copenhagen, called the “age of ocean infrastructures.”[6] In the age of ocean infrastructures, CUI is a pivotal cog in the global maritime infrastructure’s machine, especially for energy and communication.

Fossil fuels are still a major power source globally. The ocean floor is pivotal in the global petroleum products supply chain, serving as a medium for extracting and distributing crude oil and natural gas. Historically, offshore extraction installations account for around one-third of global fossil fuels production.[7] Submarine pipelines play a twin function in the energy supply chain: first, they transport hydrocarbons from offshore rigs to onshore facilities; second, they distribute them across the energy market. More than 32,000 kilometers of active pipelines are estimated to run on the seabed globally.[8]

The urgency to tackle climate change and curb greenhouse gas emissions has compelled the energy industry and governments to seek alternative energy sources. The development of offshore green energy solutions is rapidly emerging as a promising alternative to advance the energy transition, especially offshore wind farms, floating photovoltaic farms, and energy islands.[9] The market for offshore renewable energy technologies is growing. In 2023, the globally installed offshore wind and floating photovoltaic capacity reached 67.4 GW and 5.9 GW, respectively.[10] Offshore green energy farms generate renewable power at sea and use submerged cables to transmit electricity to the electrical grids.

Undersea fiber-optic cables are the communication and digital data infrastructure’s physical backbone, carrying up to 99 percent of all transoceanic digital communications.[11] As of June 2024, over 600 submarine cables operate as worldwide highways for voice and internet traffic, running on the seabed for more than 1.4 million kilometers.[12] Notably, international consortia of private companies – such as the French Alcatel Submarine Networks, the Japanese NEC Corporation, and the Chinese Huawei Marine Networks – play a paramount role in the global data architecture managing the entire life-cycle of subsea cables, from construction to deployment and maintenance.[13]

As Critical as Vulnerable

The CUI threat landscape can be organized based on two criteria. The first factor is the physical or digital domain, in which the damage to a CUI is inflicted. The second factor is intent, indicating whether the harm to a CUI results from a deliberate action or an unintentional event.

Figure 1. CUI threat landscape (Source: author’s elaboration)

Natural hazards, such as volcanic eruptions, underwater landslides, and submarine earthquakes, can potentially disrupt CUI functions. Emblematic is the volcanic eruption that disrupted the Pacific Island of Tonga’s Internet connection in 2022.[14] However, natural disasters are estimated between 10 and 14 percent of all registered cable faults.[15] Accidental human actions are the first cause of cable accidents, contributing to nearly 70 percent of annual cable faults. The fishing and shipping industries account for the largest share of cable damage, especially bottom trawling fishing methods and anchor use negligent practices.[16] The human activity’s intensification at sea is likely to result in an uptick of man-made unintentional CUI faults. However, deliberately targeting CUI as a form of sabotage constitutes a no less pressing concern for the submarine cable industry and its end-users.

Two significant factors contribute to shaping the contemporary CUI threat landscape. First, the fast-advancing technical sophistication of underwater platforms provides malign actors with effective means to conduct grey-zone warfare operations successfully. Grey-zone warfare tactics are disruptive actions short of war that reduce the offender’s detection risk while fueling ambiguity about the attribution, often making it hard for the victims to tell apart natural hazards from sabotage actions. Second, CUI networks display unprecedented interconnectedness and interdependency at regional and global levels, meaning that CUI failures can cause severe negative impacts in areas far from the accident’s epicenter.

Most recent CUI maritime accidents in the Baltic Sea are a paradigmatic example of the vulnerability of CUI and the challenges in clearly attributing responsibility for CUI faults.

On September 26, 2022, several explosions damaged three of the four pipelines of the Nord Stream, a network of submarine pipelines carrying natural gas from Russia to Germany.[17] Two-year-long investigations have proved inconclusive,[18] with the key contenders playing the blame game.[19] In mid-August 2024, Germany issued an arrest warrant for a suspected Ukrainian national over the Nord Stream blast.[20] Still, some regional countries continue to support the hypothesis of a Russian false flag attack.[21]

On October 8, 2023, a rupture was detected in the Balticconnector pipeline, a 151-kilometer natural gas pipeline connecting Finland and Estonia.[22] A Finnish naval probe confirmed damages to the gas pipeline and two telecommunication cables. Investigations focused on the Hong Kong-registered Newnew Polar Bear container ship. The Chinese vessel’s Automatic Identification System – a shipboard broadcast system – located the ship close to the Balticconnector at the accident’s time and Finnish authorities retrieved its portside anchor from the seabed close to the rupture’s site; evidence suggests the ship’s dragging anchor caused the damages.[23] China later admitted the Newnew Polar Bear’s responsibility in the event but classified it as an unintentional fault due to a tidal storm.[24] However, an Estonian-Finnish criminal investigation is ongoing to ascertain the incident’s nature.[25]

The Baltic Sea remains a critical hotbed for CUI faults. Two fiber-optic communication cables – one connecting Finland to Germany and the other running from the Swedish islands of Gotland to Lithuania – were damaged between November 17 and 18, 2024.[26] Preliminary criminal probes are still investigating the incidents, but the abrupt outage on internet communications suggests that an outside force physically disrupted the cables, either deliberately or unintentionally.[27]

Deliberate malign acts could also lead to unintended maritime accidents, as highlighted by the cutting of data cables in the Red Sea by the sinking MV Rubymar bulk carrier’s dragging anchor.[28] As part of its anti-shipping campaign,[29] Ansar Allah, a Yemeni insurgent group known as the Houthis, launched a missile attack on the bulk carrier on February 18, 2024. Ultimately, the ship sank six days later, damaging four of the around 20 data cables on the Red Sea’s seabed. The Hong Kong-based telecoms company HGC Global Communications, one of the cable owners, estimated that the accident impacted 25 percent of Asia-Europe Internet traffic.[30] Before the incident, although lacking advanced seabed sabotage capabilities, Houthi-affiliated accounts launched vague threats on social media networks to extend the conflict to the Red Sea’s ocean floor.[31] As the Houthi naval offensive drags on, conducting repair operations is a high-risk endeavor. The Red Sea remains a vital node for transcontinental data traffic,[32] and new attacks could result in more CUI faults.

Sharing the Burden

The severe uptick in CUI faults has represented a wake-up call for the military and political leadership in Europe about CUI’s underlying vulnerability to hybrid tactics and the need to design successful mitigation measures.[33]

The North Atlantic Treaty Organization (NATO) and the EU have taken concrete steps to enhance maritime situational awareness (MSA) on the ocean floor. In a nutshell, MSA seeks to improve security at sea by providing seafarers with a complete picture of any event or activity that could impact the maritime domain.[34] In practice, maritime security providers strengthen MSA by conducting monitoring operations and threat assessments, which are then shared with the different stakeholders through regular threat updates, recommendations, and safety instructions. Improved MSA on the seabed is also central to the “deterrence by detection” strategy advanced by NATO and the EU.

NATO has spearheaded multilateral efforts in CUI protection by setting up new entities specifically dedicated to CUI security and enhancing the warfighting readiness of NATO troops in the underwater domain.[35]

On the organizational side, in February 2023, the Critical Undersea Infrastructure Coordination Cell was established at the NATO headquarters in Brussels, Belgium. The brand-new NATO Cell’s core goal is to map vulnerabilities and facilitate engagements between military, civilian, and industry stakeholders.[36] In July 2023, at the Vilnius Summit, NATO member states agreed to set up NATO’s Maritime Centre for the Security of Critical Undersea Infrastructure to identify and mitigate CUI vulnerabilities and put NATO allies in the condition to prepare for, deter, and defend against hybrid threats to CUI.[37] Located at NATO’s Maritime Command in Northwood, UK, the Centre reached initial operational capability in May 2024.[38]

On the operational side, NATO allies have conducted several joint military drills in underwater tactical exercise scenarios to bolster full-spectrum submarine warfighting capabilities. For instance, Dynamic Mongoose 24 and Dynamic Manta 24 focused on anti-submarine warfare,[39] Open Spirit 24 was on mine-clearing,[40] and Dynamic Monarch 24 centered on submarine rescue.[41] These operations strengthen interoperability, ensure inter-force rapid integration, and enhance the preparedness of NATO forces in the underwater domain.

Given CUI's inherently trans-regional nature, a greater level of state-state coordination is crucial to ensure resilience. In this regard, joint NATO and the EU efforts to build synergies in promoting CUI security have proved remarkable. In January 2023, the two camps agreed to launch a joint Task Force on the resilience of critical infrastructure. The Task Force aims to ensure the resilience of critical infrastructure, technology, and supply chains strategic to the two blocs and take concrete mitigation actions through enhanced staff-to-staff cooperation.[42] In June 2023, the EU-NATO Task Force released a final assessment report on the resilience of critical infrastructure, outlining vulnerabilities and recommendations to enhance CUI protection.[43]

Conclusions

Contemporary societies and economies strive to adapt to energy and digital transitions. CUI has rapidly emerged as a pivotal enabler of a more sustainable and interconnected global system. With many essential societal functions becoming closely dependent on CUI, malign actors have displayed growing resolve and capability to weaponize CUI through grey-zone warfare tactics. The uptick in unclarified maritime accidents and sabotage acts has compelled military planners and policymakers to make CUI protection a political priority. CUI is a challenging asset to surveil when running across different juridical zones in an environment characterized by extreme geophysical conditions. Nevertheless, long-term CUI resilience and protection rest on the capacity of different stakeholders to jointly design and implement effective solutions to improve MSA on the seabed.

[1] ‘The 'underwater’ domain: the new global race is played out in the ocean depths,’ Lightbox, July 9, 2024, https://lightbox.terna.it/en/transition/underwater.

[2] Bueger, C. and Liebetrau, T., ‘Protecting hidden infrastructure: The security politics of the global submarine data cable network,’ Contemporary Security Policy, Vol. 42, n. 3, 2021, pp. 391-413, https://doi.org/10.1080/13523260.2021.1907129.

[3] ‘Council Directive 2008/114/EC on the identification and designation of European critical infrastructures and the assessment of the need to improve their protection,’ 2008, Official Journal of the European Union, L 345, p. 75, https://eur-lex.europa.eu/legal-content/en/TXT/?uri=CELEX%3A32008L0114.

[4] ‘National Infrastructure Protection Plan – Partnering to enhance protection and resiliency,’ U.S. Department of Homeland Security, 2008, p. 7, https://www.dhs.gov/xlibrary/assets/NIPP_Plan.pdf.

[5] Bueger, C. and Liebetrau, T., ‘Critical maritime infrastructure protection: What’s the trouble?,’ Marine Policy, 155, 2023, pp. 1-8, https://doi.org/10.1016/j.marpol.2023.105772.

[6] Bueger, C. ‘Maritime Security in the age of infrastructure,’ in Leucci, P. and Vianello, I. (eds) AscoMare Yearbook on the Law of the Sea Volume 3 – Maritime Security, New Technology and Ethics, Luglio Editore, 2024, p. 75, https://ascomare.com/wp-content/uploads/2024/08/ascomare_yearbook_on_the_law_of_the_sea-_-vol-3-74-89.pdf.

[7] ‘Offshore Oil and Gas Production,’ Planete Energies, November 8, 2015, https://www.planete-energies.com/en/media/article/offshore-oil-and-gas-production.

[8] Captain Don Walsh, U.S. Navy (Retired), ‘Seafloor Cables and Pipelines: Are They Secure?,’ U.S. Naval Institute, Proceedings Vol. 149/3/1,44, March 2023, https://www.usni.org/magazines/proceedings/2023/march/seafloor-cables-and-pipelines-are-they-secure.

[9] Casey, J., ‘The future is offshore,’ Energy Global, June 21, 2024, https://www.energyglobal.com/special-reports/21062024/the-future-is-offshore/.

[10] ‘Global Offshore Wind Report 2023,’ WFO, April 2024, https://wfo-global.org/wp-content/uploads/2024/04/WFO-Report-2024Q1.pdf. ‘Global Floating Solar Market Research Report: Forecast (2024-2030),’ MarkNtel Advisors, July 2024, https://www.marknteladvisors.com/research-library/global-floating-solar-market.html#:~:text=The%20Global%20Floating%20Solar%20Market,around%205.9%20GW%20in%202023.

[11] ‘Undersea Telecommunication Cables: Technology Overview and Issues for Congress,’ Congressional Research Service, September 13, 2022, https://crsreports.congress.gov/product/pdf/R/R47237.

[12] ‘Submarine Cable Frequently Asked Questions,’ TeleGeography, https://www2.telegeography.com/submarine-cable-faqs-frequently-asked-questions.

[13] Csernatoni, R., ‘The Geopolitics of Submarine Cables, the Infrastructure of the Digital Age,’ ISPI, June 22, 2022, https://www.ispionline.it/en/publication/geopolitics-submarine-cables-infrastructure-digital-age-35516.

[14] Herlevi, A. ‘Pacific Connectivity and Tonga’s Volcanic Eruption,’ CNA, February 3, 2022 https://www.cna.org/our-media/indepth/2022/02/pacific-connectivity-and-tongas-volcanic-eruption.

[15] Claire, M., ‘Submarine Cable Protection and the Environment. An Update from the ICPC,’ International Cable Protection Committee, April 2024, https://www.iscpc.org/publications/submarine-cable-protection-and-the-environment/. ‘The Biggest Threat to Subsea Cables,’ Ultramap Global, April 19, 2021, https://www.iscpc.org/publications/submarine-cable-protection-and-the-environment/ICPC_Public_EU_March%202021.pdf.

[16] ‘The Biggest Threat to Subsea Cables,’ Ultramap Global.

[17] ‘The Pipeline,’ Nord Stream, https://www.nord-stream.com/the-project/pipeline/.

[18] Ahlander, J. and Ringstrom, A., ‘Sweden ends Nord Stream sabotage probe, hands evidence to Germany,’ Reuters, February 7, 2024, https://www.reuters.com/world/europe/sweden-ends-investigation-into-nord-stream-pipeline-blasts-2024-02-07/; Jacobsen, S. and Rasmussen, L., ‘Denmark ends probe into 'deliberate' Nord Stream pipeline blasts,’ Reuters, February 26, 2024, https://www.reuters.com/world/europe/denmark-ends-investigation-into-nord-stream-pipeline-blasts-2024-02-26/.

[19] ‘Russia’s Lavrov says ‘clear’ that US ordered 2022 Nord Stream blasts,’ Al Jazeera, August 2024, https://www.aljazeera.com/news/2024/8/19/russias-lavrov-says-clear-that-us-ordered-2022-nord-stream-blasts.

[20] Giordano, E. ‘Germany issued arrest warrant for Ukrainian over Nord Stream bombing, reports say,’ Politico, August 14, 2024, https://www.politico.eu/article/german-authorities-obtain-first-arrest-warrant-ukraine-nord-stream-bombing/.

[21] Janjevic, D., ‘Nord Stream sabotage: How are the key players reacting?,’ DW, August 16, 2024, https://www.dw.com/en/nord-stream-sabotage-how-are-key-players-reacting/a-69964635.

[22] ‘Explainer: What is the Balticconnector pipeline?,’ Reuters, October 11, 2023, https://www.reuters.com/business/energy/what-is-balticconnector-pipeline-2023-10-10/. 

[23] Lehto, E., ‘Finland says gas pipeline likely broken by ship dragging anchor,’ Reuters, October 24, 2023, https://www.reuters.com/world/europe/finland-retrieves-anchor-seabed-near-broken-gas-pipeline-2023-10-24/.

[24] Berminghamin, F., ‘Beijing admits Hong Kong-flagged ship destroyed key Baltic gas pipeline ‘by accident’,’ South China Morning Post, August 12, 2024, https://www.scmp.com/news/china/diplomacy/article/3274120/china-admits-hong-hong-flagged-ship-destroyed-key-baltic-gas-pipeline-accident.

[25] ‘China admits container ship Newnew Polar Bear damaged undersea gas pipeline,’ EER News, August 12, 2024, https://news.err.ee/1609422658/china-admits-container-ship-newnew-polar-bear-damaged-undersea-gas-pipeline.

[26] Newdick, T., ‘Sabotage Claims Swirl Around Severed Baltic Sea Cable Incidents,’ The War Zone, November 19, 2024, https://www.twz.com/news-features/sabotage-claims-swirl-around-severed-baltic-sea-cable-incidents#:~:text=Germany%20says%20that%20damage%20to,a%20series%20in%20the%20region..

[27] Sytas, A., Erling, B., and Ahlander, J., ‘European nations denounce Russian hybrid attacks, cable cut probes launched,’ Reuters, November 19, 2024, https://www.reuters.com/business/media-telecom/lithuania-steps-up-surveillance-sea-following-damage-undersea-cable-2024-11-19/.

[28] Watson, E., ‘Ship sunk by Houthis likely responsible for damaging 3 telecommunications cables under Red Sea,’ CBS News, March 6, 2024, https://www.cbsnews.com/news/houthis-ship-cutting-red-sea-telecommunications-cables/.

[29] Noam Raydan, N. ‘Houthi Ship Attacks Pose a Longer-Term Challenge to Regional Security and Trade Plans,’ The Washington Institute for Near East Policy, June 26, 2024, https://www.washingtoninstitute.org/policy-analysis/houthi-ship-attacks-pose-longer-term-challenge-regional-security-and-trade-plans.

[30] ‘Statement - Supplementary Information of HGC Global Communications Regarding Submarine Cable Damage in the Red Sea To Demonstrate Hong Kong as International Telecommunication Hub,” HGC Global Communication, March 4, 2024, https://www.hgc.com.hk/press-releases/statement-supplementary-information-of-hgc-global-communications-regarding-submarine-cable-damage-in-the-red-sea-to-demonstrate-hong-kong-as-international-telecommunication-hub-to-demonstrate-hong-kong-as-international-telecommunication-hub.

[31] ‘In Veiled Threat, Telegram Channels Linked To Houthi Ansar Allah Movement Point To Submarine Internet Cables Off Yemeni Coast,’ MEMRI, December 26, 2023, https://www.memri.org/jttm/veiled-threat-telegram-channels-linked-houthi-ansar-allah-movement-point-submarine-internet.

[32] ‘Submarine Cable Map,’ TeleGeography, https://www.submarinecablemap.com/.

[33] Milne, R., Foy, H., and David, S., ‘Sabotage of gas pipelines a wake-up call for Europe, officials warn,’ Financial Times, September 29, 2022, https://www.ft.com/content/ad885fea-035f-4b93-98e7-c75da2c308f8.

[34] ‘Maritime Situational Awareness,’ NATO Centre of Excellence for Operations in Confined and Shallow Waters, https://www.coecsw.org/our-work/projects/maritime-situational-awareness/.

[35] Monaghan, S. et. al., ‘NATO’s Role in Protecting Critical Undersea Infrastructure,’ CSIS, December 19, 2023, https://www.csis.org/analysis/natos-role-protecting-critical-undersea-infrastructure. Bueger, C., ‘NATO’s Contribution to Critical Maritime Infrastructure Protection,’ Center for Maritime Strategy, January 19, 2024, https://centerformaritimestrategy.org/publications/natos-contribution-to-critical-maritime-infrastructure-protection/.

[36] ‘NATO stands up undersea infrastructure coordination cell,’ NATO, February 15, 2023, https://www.nato.int/cps/en/natohq/news_211919.htm.

[37] ‘Vilnius Summit Communiqué,’ NATO, July 2023, https://www.nato.int/cps/en/natohq/official_texts_217320.htm.

[38] ‘NATO officially launches new Maritime Centre for Security of Critical Undersea Infrastructure,’ NATO, May 28, 2024, https://mc.nato.int/media-centre/news/2024/nato-officially-launches-new-nmcscui.

[39] ‘Dynamic Mongoose 24 strengthens NATO’s anti-submarine warfare capability, including new ally Sweden,’ NATO, May 10, 2024, https://mc.nato.int/media-centre/news/2024/dynamic-mongoose-24-strengthens-nato-antisubmarine-warfare-capability-including-sweden; ‘NATO boosts anti-submarine, anti-surface warfare readiness during exercise Dynamic Manta in Italy,’ NATO, March 11, 2024, https://mc.nato.int/media-centre/news/2024/nato-boosts-antisubmarine--antisurface-warfare-readiness-during-exercise-dynamic-manta-in-italy.

[40] ‘Minesweeping the Baltic Sea on Open Spirit 2024,’ NATO, April 29, 2024, https://mc.nato.int/media-centre/news/2024/minesweeping-the-baltic-sea-on-open-spirit-2024.

[41] ‘NATO demonstrates close collaboration between Allies in submarine rescue Exercise Dynamic Monarch 24,’ NATO, September 23, 2024, https://mc.nato.int/media-centre/news/2024/nato-demonstrates-close-collaboration-between-allies-in-submarine-rescue-exercise-dynamic-monarch-24.

[42] ‘NATO and the EU set up taskforce on resilience and critical infrastructure,’ NATO, January 11, 2023, https://www.nato.int/cps/en/natohq/news_210611.htm.

[43] ‘EU-NATO TASK FORCE ON THE RESILIENCE OF CRITICAL INFRASTRUCTURE – FINAL ASSESSMENT REPORT,’ European Commission, June 2023, https://commission.europa.eu/system/files/2023-06/EU-NATO_Final%20Assessment%20Report%20Digital.pdf.