From the Digital Silk Road to the Seabed: The Global Architecture of Cables as a Vector of Chinese Influence - Analysis

How China is Rewriting the Submarine Cable Map and Redrawing the Global Digital Balance

The submarine communications cable (SCC) infrastructure is not just a commercial asset but the critical backbone of global connectivity. These cables handle approximately 99% of the world's digital communications and underpin financial transactions estimated at $10 trillion daily. With over 400 active cables spanning at least 1.3 million kilometers, their integrity is a national security imperative for all states reliant on the digital economy.

The People's Republic of China (PRC) has evolved from a user to a fundamental global player, system integrator, and infrastructure protector in this domain. China's strategy rests on a dual principle: declared commitment to open cooperation, mutual benefit, and fair competition, balanced by accelerated technological self-sufficiency and a powerful projection of force in installation and maintenance. The strategic goal is to establish a "Digital Silk Road" by diversifying routes, reducing reliance on historical Western contractors, and increasing global influence.

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Technological Ascent and Core Capabilities

The PRC has made significant R&D investments, achieving substantial results in technology, equipment, and engineering, becoming one of the most important technical forces in global cable development.

Hard Power Capabilities

Chinese enterprises have developed independently owned intellectual property for core products, including submarine fiber optic cables, repeaters (海底中继器), and branch units (海底分支器).

• Deep Sea Resilience: Cable repeaters and branch units utilize high-reliability redundant designs, enabling stable operation for 25 years at depths of up to 8,000 meters.

• Ultra-High Capacity: Chinese firms were pioneers in launching the 32-fiber pair solution and full product series, utilizing SDM (Space Division Multiplexing) technology to support Petabit-level transmission capacity over ultra-long distances. For example, the PEACE international cable system has a designed capacity of 192 Tbps.

• Open Cable Leadership: The PRC is a strong supporter of the Open Cable standard. This solution allows customers flexibility in selecting terminal transmission equipment, supporting multi-vendor access and flexible bandwidth allocation via spectrum management and Optical Add/Drop Multiplexing (OADM).

Operational and Logistical Assets

The growth of Chinese general contractors and construction firms directly translates into projection capability and logistical independence.

• Global System Integration: HMN (Hua Hai Communication) has established itself as one of the four major global general contractors (alongside SubCom, ASN, and NEC). HMN has built over 140 cable projects across more than 70 countries, with its wet-end communication equipment achieving zero cumulative faults over 16 years.

• Advanced Maritime Equipment: Chinese manufacturing firms and cable companies have jointly developed advanced equipment, including ROVs (水下机器人), ploughs (埋设犁), and cable-laying machines (布缆机), achieving internationally leading performance levels.

• Construction and Maintenance Fleet: Chinese enterprises possess professional cable-laying vessels certified for unlimited navigation areas (无限航区). Companies like China-Ugland Submarine Systems (中英海底) have participated in over 130 key domestic and international projects and have installed over 70,000 kilometers of cable across the Pacific, Indian, and Atlantic Oceans.

Mapping Strategic Assets and Geopolitical Leverage

Chinese enterprises have invested in or constructed 17 active international and Hong Kong/Macao/Taiwan cable systems as of the end of 2024. This geographical spread is critical to securing global connectivity for the PRC and its partners.

Key Active and Under-Construction Cable Systems

Cable (Acronym)	Strategic Direction	Chinese Participation (Lead/Investment)	Geopolitical Significance
PEACE	Asia - Africa - Europe	HMN (Construction)	A vital alternative route connecting three continents; total length over 22,000 km.
2Africa	Circum-Africa, connects Europe/Middle East/Asia	China Mobile (Co-initiator)	World’s largest cross-ocean cable (45,000 km); strengthens ties with 33 African countries.
SAIL	Africa - South America	China Unicom (Lead)	The world's first direct cable across the South Atlantic; opened new low-latency routes.
ADC	Asia-Pacific	China Telecom/China Unicom (Lead)	Enhances network redundancy in the Asia-Pacific region with a capacity over 160 Tbps.
TPE / NCP	Trans-Pacific (US Direction)	China Investment	Key links despite being constructed by US/Japanese firms.
SMW5 / AAE-1	Asia - Europe	China Investment	Core components of the major Euro-Asian fiber arteries.
SJC2 / ALC / SEA-H2X / SMW6	In Construction	China Investment/Construction	Further expansion and consolidation of routes in Southeast Asia, Africa, and the Middle East.

Asymmetric Threat and Global Vulnerability

The PRC's expansion occurs amidst the growing risk associated with strategic vulnerability of SCCs. Recent events underscore how easily communications can be crippled: an incident in the Red Sea interrupted 25% of traffic between the Middle East, Asia, and other continents, while the damage to four cables affected 13 African countries in March 2024.

The Hybrid Warfare Risk

The extensive involvement of Chinese companies, including Huawei Marine Networks and HMN, in construction and maintenance is viewed by security services and allied nations as a potential instrument of hybrid warfare. The access and technical expertise gained could be exploited for:

1. Espionage: Concerns have grown that China could use its presence in the SCC sector for espionage.

2. Sabotage or Destruction: Deliberate cutting or damaging of cables, which is seen as a concrete threat to national and economic security.

3. Pressure Geopolitica: Using infrastructure control as a weapon of pressure.

In a crisis or conflict scenario, China's capability to disrupt global communications poses a significant asymmetric threat.

Protection, Maintenance, and Security Assurance

Major Western powers and allied organizations, including NATO and the United States Government, are strengthening surveillance and defense measures due to the devastating consequences an attack could have.

The PRC officially guarantees neutrality, claiming:

• They support the Open Cable standard, which ensures compatibility with transmission equipment from different manufacturers.

• Chinese firms assert that they do not access any data transmitted on the cables, and management is fully transferred to the operator after project completion.

• China-Ugland Submarine Systems has participated in the Yokohama Maintenance Area (responsible for the Northwest Pacific) for over 27 years, operating one vessel constantly on rotation.

• Domestically, Chinese protection teams have patrolled over 5 million kilometers since 2015 and have successfully deterred or persuaded over 60,000 vessels from endangering international cables.

Strategic Conclusions: The Dual-Use Risk

China's expansion is an advanced national security and economic strategy. The technological capability, logistical projection, and the establishment of new, resilient routes grant the PRC a unique and growing geopolitical advantage.

While commercially driven, the PRC's control over such complex and resilient infrastructure provides leverage that extends far beyond commerce, making the SCC domain a critical fault line in contemporary geopolitics.