Subsea Secrets: Spies, Sabotage, and the Global Race for Internet Cables

CRITICAL CONTEXT: THE DEVELOPMENT OF INTERNATIONAL TELECOMMUNICATIONS

To understand why these cables have become battlegrounds, we need to look at how they evolved from simple telegraph lines to the critical infrastructure of global communication.

Early Subsea Telegram Cables:

After early successes over short distances, subsea telegraph cables rapidly expanded, connecting distant parts of the world.

• The First Cable (1847): Enabled by gutta-percha, a natural latex used for insulation, the first underwater telegraph cable was laid across the Rhine River, linking Cologne and Deutz in Germany.

• The English Channel (1850): Just three years later, a cable was installed between England and France, marking the first international subsea connection.

• The First Transatlantic Cable (1858): The Atlantic Telegraph Company successfully laid the first cable from Ireland to Newfoundland, connecting Europe and North America with the first message taking 16.5 hours. After just three weeks, the cable broke. 

These rapid breakthroughs set the stage for a global network of telegraph lines, revolutionizing communication in the decades that followed.

The Modern Evolution of Subsea Cables

As communication technology advanced, subsea cables evolved to carry more than just telegraph signals. Innovations in telephone and fiber-optic technology transformed them into the backbone of global connectivity.

• Transatlantic No. 1 (TAT-1) (1956): A collaboration between AT&T Bell Laboratories, the British Post Office, and the Canadian Overseas Telecommunications Corporation resulted in the first transatlantic cable designed for telephone communication.

• The Fiber-Optic Revolution (1988): The introduction of fiber-optic cables with TAT-8 marked a major leap, offering a tenfold increase in capacity over copper cables. Today, a single fiber-optic cable can transmit terabits of data per second—enough to stream millions of 4K videos simultaneously.

• The Internet Era: The demand for high-speed global data transmission has surged, with over 95% of international internet traffic now traveling through subsea fiber-optic cables. More than 570 underwater cables crisscross the globe, forming the backbone of our digital world.

THE INDUSTRY: DEVELOPMENT, OWNERSHIP, AND CONTROL

The modern subsea cable industry is a global, and primarily private-owned and operated, industry. 

The Developers and Operators: 

As of 2021, four companies dominated the design, manufacturing, deployment, and maintenance of subsea cables, collectively holding 98% of the total market:

• SubCom (USA): An industry leader in subsea fiber optic cable engineering, manufacturing, and installation. They have deployed over 200 submarine systems worldwide.

• NEC Corporation (Japan): Actively aiming to become the world's leading supplier, NEC has built more than 400,000 km of cable, enough to circle the Earth nearly 10 times.

• Alcatel Submarine Networks (France): A strategic French company, now 80% state-owned (acquired in 2024), has deployed over 850,000 km of optical submarine systems worldwide, which is enough to circle the Earth nearly 21 times as of 2025.

• HMN Technologies (China): The fastest-growing subsea cable builder, responsible for 18% of global cable installations over four years, leveraging cost advantages and targeting emerging markets. They were previously owned by Huawei, a company blacklisted by the US and suspected of espionage. 

The Owners

Private organizations control 99% of subsea cables, with tech giants accounting for nearly half of all undersea bandwidth. Companies like Meta, Google, and Amazon have invested billions in infrastructure to expand global connectivity.

Major Tech-Backed Projects

• Apricot – A 12,000 km cable connecting Japan, Taiwan, Guam, the Philippines, Indonesia, and Singapore, owned by Google, Meta, and telecom partners, with a 190 Tbps capacity (expected completion in 2024 but now delayed).

• Curie – A 10,500 km Google-owned cable linking the U.S. to Chile (with a branch to Panama), operational since 2020 with a 72 Tbps capacity.

• Project Waterworth – A Meta-led, 50,000 km project connecting the U.S., India, Brazil, South Africa, and beyond, set to be the world's longest subsea cable (rumored cost: $2 billion; timeline unspecified).

• 2Africa – A 45,000 km subsea cable backed by a consortium, including Meta, that will encircle Africa while connecting Europe and the Middle East. With a capacity of 180 Tbps, it is set to become the largest subsea cable ever upon its expected completion in Q4 2025.

Governments own less than 1% of the world’s subsea cables.

The Rulers: 

Beyond physical ownership, control of subsea cables also hinges on legal and regulatory frameworks, which differ across territorial and international waters.

• Territorial Waters (0–12 nautical miles) – Each country has full control over cables within its territorial waters and can impose regulations on their installation and operation.

• Exclusive Economic Zone (EEZ) & Continental Shelf – Coastal states have limited jurisdiction, meaning they cannot prevent cable laying but may enforce measures to protect their natural resources.

• International Waters (High Seas) – All nations have the unrestricted right to lay and maintain submarine cables without interference.

Key Regulatory Bodies

• UNCLOS (United Nations Convention on the Law of the Sea) – The primary legal framework governing submarine cables, defining rights and responsibilities across different maritime zones. While UNCLOS mandates penalties for intentional cable damage in high seas (Article 113), enforcement is weak, as jurisdiction lies with the ship’s flag state or the individual’s nationality, not the cable owner’s country.

• FCC (Federal Communications Commission) – In the U.S., the FCC licenses and regulates submarine cables landing in U.S. territory but has no authority beyond U.S. waters.

BREAKS, BLUNDERS, AND BATTLES: WHEN SUBSEA CABLES GO DARK

Each year, 150–200 undersea cable faults occur globally, primarily due to fishing, anchoring, and accidental damage. Natural causes like earthquakes and underwater landslides account for a smaller share. While most breaks are unintentional, concerns over sabotage are rising, particularly in the Baltic Sea and Taiwan Strait.

Baltic Sea: Sabotage Concerns and Investigations

Since 2023, at least 10 undersea cables in the Baltic Sea have been damaged, with investigations raising suspicions of foreign involvement:

• Anchor Damage Evidence: Tracking data indicates that Russian and Chinese vessels have been dropping and dragging anchors near undersea cables. A key example is the Eagle S, a vessel believed to be part of Russia’s "shadow fleet". On December 25, 2024, it is suspected of causing damage to the EstLink 2 power cable and four telecom lines. Evidence includes:

  • A 50km km seabed drag trace matching the Eagle S’s route, ending near the recovered anchor.

  • An 11-ton anchor retrieved by Finnish authorities near the Porkkala Peninsula, showing a cracked crown and shortened flukes—damage inconsistent with standard anchor operations.

  • The Eagle S was missing one anchor when detained, and historical photos show it previously used different anchor types.

• November 2024 Incidents: On November 17-18, 2024, the BCS East-West Interlink and C-Lion1 submarine cables in the Baltic Sea were damaged. The Chinese cargo ship Yi Peng 3 was in the area and is under investigation. Western intelligence suspects its anchor may be responsible, possibly under Russian influence, but no conclusive sabotage evidence has been found.

• Official Assessments: Some cases remain unexplained, while others—such as the January 2025 Vezhen case, involving the Maltese-flagged bulk carrier MV Vezhen—were ruled accidental.

In response, NATO launched the Baltic Sentry mission in January 2025, deploying drones, frigates, and patrol aircraft to monitor critical infrastructure and vessel activity.

Taiwan Strait: Repeated Cable Disruptions

Taiwan has reported over 30 cable disruptions since 2020, particularly near its outlying islands. Key factors include:

• Frequent Vessel Activity: Many incidents involve Chinese fishing boats and sand dredgers near Taiwanese communications infrastructure.

• Recurring Damage: In January 2025 alone, four cables were severed. Some were attributed to natural wear, while others raised concerns over deliberate interference.

Geopolitical and Military Responses: A Strategic Vulnerability

Undersea cables are critical for global communication and security. Their disruption—whether accidental or intentional—has major geopolitical and economic consequences, yet responses remain limited.

• Baltic Sea: NATO has increased surveillance, but isolated incidents have not met the threshold for an Article 4 or 5 response.

• Taiwan Strait: Taiwan has strengthened patrols and backup communication systems, yet deterring further disruptions remains a challenge.

The difficulty of attributing responsibility—combined with the high strategic impact—makes undersea cable sabotage an attractive tool in modern geopolitical competition. As reliance on these networks grows, so too does society’s vulnerability.

MURKY WATERS: ESPIONAGE

Beyond cutting cables, intelligence agencies have long sought to exploit them as sources of strategic information. Tapping into a cable can often be more valuable than merely destroying it.

World War II: British Interception of German Cables

The British Navy tapped German subsea cables, intercepting encrypted messages crucial to the war effort. A major success was the Zimmermann Telegram, which revealed Germany’s proposal to Mexico for an alliance against the U.S., influencing America’s entry into the war.

Cold War: Operation Ivy Bells

From 1971, the CIA, NSA, and U.S. Navy ran Operation Ivy Bells, tapping Soviet cables in the Sea of Okhotsk. Using a modified submarine, U.S. operatives retrieved recordings undetected until NSA analyst Ronald Pelton exposed the operation in 1980, leading the Soviets to dismantle the tap.

Post-9/11: Mass Surveillance

By the 2000s, undersea surveillance had expanded globally. Edward Snowden’s 2013 leaks revealed:

• 200+ Cables Tapped: Nearly every international connection entering the U.S. was intercepted.

• NSA’s Interception Centers: Facilities like AT&T’s Room 641A (San Francisco) and PINECONE (New Jersey) processed vast data streams.

• GCHQ’s Global Spy Bases:

  • CIRCUIT (Oman) tapped cables in the Strait of Hormuz.

  • REMEDY (BT) & GERONTIC (Vodafone) secretly transmitted customer data, covering 70% of GCHQ’s undersea cable surveillance.

• XKeyscore & PRISM: Programs analyzing intercepted data, with PRISM extracting user information from tech giants such as Google, Meta, Microsoft, etc. Many of the same companies now own much of the undersea cable infrastructure.

Since the exposure of U.S. tapping practices, global subsea cable infrastructure has increasingly shifted toward China, driven by its Digital Silk Road initiative. 

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A SHIFT TOWARDS CHINA AND THE U.S. RESPONSE

The subsea cable industry has experienced significant geopolitical changes over the past decade, with new players challenging traditional power structures.

China's Expanding Presence in Subsea Cable Development

• The Digital Silk Road Initiative (2015): China's initiative seeks to control 60% of the global fiber-optic cable market, launched at a strategic moment capitalizing on global concerns over U.S. espionage claims.

• HMN Technologies: Formerly Huawei Marine Networks, HMN has become the fastest-growing subsea cable builder, using cost advantages to target emerging markets.

U.S. Response to China’s Subsea Cable Ambitions

• UnderSea Cable Control Bill (2023): The U.S. has passed this bill to limit China’s access to subsea cable technology, signaling rising tensions over digital infrastructure.

• Access Restrictions: The U.S. has blocked Chinese firms from subsea cable projects involving U.S. investment or technology.

• Project Denials: The U.S. government has rejected several projects, including the Pacific Light Cable Network (PLCN), Hong Kong-Americas (HKA), and Hong Kong-Guam (HK-G), citing national security concerns.

• Southeast Asia-Middle East-Western Europe 6 (SMW6): The U.S. successfully removed HMN Technologies from this $600 million project linking Singapore to France, ensuring a U.S. company, SubCom, won the contract.

This evolving landscape demonstrates how subsea cables are no longer just about connecting continents—they are becoming vital assets in the ongoing geopolitical struggle for influence, security, and control over the communications infrastructure upon which modern economies rely.

ALTERNATIVE SYSTEMS: LOW EARTH ORBIT (LEO) ADDRESS CABLE VULNERABILITIES

Satellite-based internet, particularly Low Earth Orbit (LEO) constellations like Starlink and Oneweb, is gaining traction as an alternative to traditional subsea cables, addressing several vulnerabilities tied to undersea infrastructure:

• Resilience to Physical Damage: Unlike subsea cables, which are vulnerable to natural disasters and human activity, satellite networks are immune to physical cuts.

• Global Coverage: LEO satellites can provide internet access to remote or underserved areas, including small island nations that may not justify the cost of dedicated submarine cables.

• Rapid Deployment: In the event of cable disruptions, satellites can quickly restore connectivity, as seen in past incidents.

• Improving Technology: Though satellite capacity currently falls short of subsea cables, advancements like Starlink’s laser inter-satellite links are progressing rapidly, potentially outperforming some undersea routes.

In Taiwan, a space-based internet system has been implemented as a backup to ensure connectivity, particularly for the Matsu Islands, in case of persistent damage to existing subsea infrastructure.

However, satellites are not yet a full replacement for subsea cables due to bandwidth limitations and higher operational costs. A hybrid approach combining both systems may be the future, enhancing global connectivity resilience.