Why a Chinese Law Professor Says Existing Law Leaves Undersea Cables Defenseless Against Grey-Zone Sabotage

The undersea fibre-optic cables that carry roughly 99% of the world's intercontinental data face a new generation of threats — but the laws that should protect them were written for a different era, according to a prominent Chinese legal scholar.

Shanghai Maritime University law professor Guo Ran published an analysis in the July 2026 issue of Democracy and Legal System — a policy journal supervised by the China Law Society — arguing that Beijing should create a dedicated domestic law to safeguard undersea fibre-optic cables . Guo's central claim is that existing Chinese regulation and traditional international maritime law both fail to address modern "grey-zone warfare" tactics — actions in which adversaries can damage critical seabed infrastructure while remaining hard to attribute or prosecute .

The critical infrastructure gap: What China's current laws miss

Guo identifies four specific gaps in China's existing legal framework :

1. No coverage of physical seabed infrastructure. China's Data Security Law and Cybersecurity Law regulate how data is processed and how it flows across borders. But they do not cover the physical undersea cables that carry that data . The cables themselves — the actual fibre-optic lines lying on the seabed — sit outside both legal regimes.

2. UNCLOS offers insufficient defence against grey-zone sabotage. The 1982 United Nations Convention on the Law of the Sea (UNCLOS) protects the freedom to lay cables, but it provides few enforcement mechanisms when state-linked vessels deliberately damage cables in international waters. The problem is especially acute when vessels claim flag-state immunity — a legal doctrine that shields a ship from the jurisdiction of other countries .

3. No domestic legal basis for enforcement in China's own waters. Coastal states can punish cable damage in their territorial sea only if their domestic law explicitly criminalises such acts. Guo contends that China currently lacks that domestic statutory foundation, creating a legal vacuum even in waters where China has sovereignty .

4. No classification as 'critical information infrastructure.' Submarine cables are not yet designated as critical information infrastructure (CII). That means they do not receive the enhanced state protection that already applies to sectors such as power grids and nuclear facilities .

The era of grey-zone warfare and the digital Silk Road

Guo's argument is set against rising global concern about sabotage of the ocean infrastructure that underpins the internet — data that feeds global AI systems, cloud computing, and international financial markets . Reports of vessels dragging anchors to intentionally cut cables, and of suspicious activity near cable landing stations, have multiplied in recent years, placing submarine cable security on the agenda of defence ministries, think tanks, and international law scholars .

Guo frames China's vulnerability as especially acute because of its dual role: it is both a major coastal state with extensive territorial waters and a key investor in the Digital Silk Road — the infrastructure arm of the Belt and Road Initiative that is building out fibre-optic networks across Asia, Africa, and beyond . For Beijing, the question is not theoretical. China already has a state presence in many of the world's most strategically important undersea cable routes .

What a new Chinese law should include

Guo's article in Democracy and Legal System proposes a set of concrete measures that a new Chinese law should adopt :

• Designate subsea cables as critical information infrastructure (CII): This would automatically trigger higher-level state protection obligations, surveillance, and incident reporting requirements.
• Establish no-anchor zones: These would be created in sensitive straits and high-risk fishing grounds where anchoring and trawling are the leading causes of accidental cable damage.
• Expand China's domestic cable repair capacity: Much of the world's underwater cable maintenance and repair is still carried out by a small number of foreign-flagged vessels. Guo calls for reducing that dependency.
• Deploy satellite surveillance, underwater drones, and seabed sensors: A technology-driven monitoring system, combined with cross-agency coordination among maritime, communications, and security authorities, would provide real-time awareness of threats.

Guo calls on Beijing to "establish a governance system for international subsea cable security that has both international legal legitimacy and practical defence capabilities" .

A global problem with a fragmented legal answer

The legal problem Guo identifies is not unique to China. International law experts at the Center for Strategic and International Studies (CSIS) have also described the existing treaty penalties for intentional cable damage as "woefully inadequate" and the prosecutorial gaps as allowing "bad actors to escape meaningful accountability" . Academic commentary has similarly noted that the legal framework governing cyber operations and physical interference with submarine cables remains "underdeveloped and fragmented" across peacetime, grey-zone, and armed-conflict contexts .

A 2023 paper from the U.S. Department of Defense recommended that India and its allies secure cables through monitoring, contingency planning, and multilateral cooperation — measures that overlap significantly with Guo's proposals for China . And a 2026 study of the South China Sea argued that cable infrastructure has become a domain of "pre-emptive infrastructure power," where states seek to shape cable networks at the construction stage to secure future strategic advantage .

The convergence across these analyses — from Beijing, Washington, New Delhi, and academic institutions — suggests that the undersea cable security gap is a truly global challenge, and that Guo Ran's call for a dedicated legal framework may be read as part of a much wider conversation about how to protect the physical backbone of the internet.