On March 21, 2025, the South China Morning Post (SCMP) reported that China has developed a powerful deep-sea cable-cutting device, spotlighting a technology that’s raising eyebrows worldwide. The story broke after a peer-reviewed paper appeared on February 24 in the Chinese journal Mechanical Engineer (机械工程师), titled “深海缆线电动切割装置设计” or “Design of an Electric Cutting Device for Deep-Sea Cables.” Authored by researchers from the China Ship Scientific Research Centre (CSSRC) and the State Key Laboratory of Deep-Sea Manned Vehicles, the paper detailed successful ground trials, thrusting this device into discussions about global communication and maritime security.
However, the source of the breakthrough claim has raised doubts about the authenticity of the innovation as the journal in question seemingly follows dubious publication practices. It’s worth noting the source of the SCMP’s story that has fueled worldwide dialogue on maritime security.
What Is China’s Deep-Sea Cable Cutter and How Does It Work?
The Deep-Sea Cable cutter, an engineering marvel and first of its kind, is engineered to sever armored underwater communication and power cables at depth upto 4000 meters (13,123 feet), which is twice the operational depth of the existing underwater sea cables. Forged with titanium alloy shell and oil-compensated seals, the cable cutter consists of 150mm diamond-coated grinding wheel spinning at 1600 rpm. The ground trials demonstrate its ability to slice cables of upto 60mm thickness. The design of the device minimises sediment disturbance and enables it to operate at extreme deep-sea pressure. Additionally, it can be integrated with China’s advanced submersibles, including the Fendouzhe (Striver) and Haidou series and has the ability to be operated remotely and discretely via robotic arms.
Why Was It Built?
Officially, this device is meant for civilian uses, including seabed mining and salvaging operations. The paper frames it as a practical tool, not a weapon. Yet, its ability to target “armored cables”—the kind that carry internet and power—hints at dual-use possibilities. In a conversation with India’s World, Captain Sarabjeet Parmar questions the civilian utility of the cable cutter as its design doesn’t align logically with mining needs, which require drills or scoops, not precision cutters. Captain Parmar sees in the outbreak of the news a Chinese strategic ploy to test global perceptions and provoke reactions. The cable cutter breakthrough has parallels to the Chinese narrative about its DF-21D Anti-Ship Ballistic Missiles program, dubbed famously as carrier killers. However, the debate on the operational efficacy of the missiles remain inconclusive.
A Lowy Interpreter analysis also supports Parmar’s contention on the potential Chinese motives. Since most deep sea cables are not heavily fortified in the first place, the actual operational utility of the device is circumspect. In this background, the announcement can be read as a signaling device on part of China to set a favourable narrative about its strategic prowess to both domestic and foreign audiences. The potential overreaction on part of the Western powers might inadvertently favour China’s own cable industry as the Western cable companies are compelled to undertake resiliency measures.
Why Are Undersea Cables Critical, and Is This Threat New?
Undersea cables are the world’s digital arteries, carrying over 95% of global internet and telecom data, as well as power. These cables are crucial to global connectivity, spanning thousands of miles across ocean floors and serving as the backbone of the modern digital economy by facilitating approximately $10 trillion in financial transfers daily. However, they are vulnerable to damage caused by anchors, fishing nets, or even deliberate sabotage acts. Incidents such as the Baltic Sea cuts in October 2023, the disruptions in Taiwan, and the 2022 Nord Stream pipeline explosions have raised suspicions of deliberate sabotage, particularly involving Chinese interference. Beijing, on its part, has dismissed the disruptions as common sea accidents.
The recent introduction of a new cutter with a 4,000-meter reach amplifies these concerns, as it outstrips the depths of most cables. Although many cables are buried in the seabed in certain regions, they remain susceptible to hybrid warfare tactics, as seen in the cable disruptions in Marseille in October 2022, which affected connectivity across Europe, Asia, and Africa. The public availability of cable locations, limited surveillance, and the challenge of monitoring vast maritime expanses further highlight their strategic importance and fragility, prompting calls for enhanced security measures. So, while threat to undersea cables isn’t new given their vulnerability, the demonstrated efficiency of device at exploiting it adds a new sense of urgency to address the threat.
China’s Maritime Goals and Strategic Implications
This feat closely aligns with China’s maritime ambitions. With the world’s largest fleet of advanced submersibles and projects like a 2,000-meter-deep “space station” in the South China Sea, Beijing is demonstrating its deep-sea technological prowess. The cutter’s unveiling marks the first time a nation has openly showcased such a capability, positioning China as a submersible tech leader. Although, officially it’s for civilian tasks like seabed mining, salvaging operations etc., its potential to sever communication networks has sparked weaponization concerns. Analysts suggest this development could alter maritime power dynamics, especially in contested waters. Previous incidents involving undersea cables, combined with this technology, indicate that China may be able to exploit vulnerabilities beneath the waves in a conflict. The stealth features, precision and depth of its operability suggest a broader potential than just civilian use and exacerbate worries.
What’s Next for Global Responses?
The tenor of alarming response to the Chinese innovation indicates a sense of threat perception in response to China’s growing capabilities. The responsive options include beefing up the cable armor, deploying seabed sensors, or patrolling key routes with drones and submarines. The North Atlantic Treaty Organization has already boosted its Baltic Sea presence after the 2024 cuts and Taiwan is watching its waters closely post-2023 incident. The cutter could also potentially spark a quiet arms race in maritime tech, with countries racing to protect against or match China’s deep-sea capabilities. If China deploys its cable cutter, expect diplomatic ripples too— calls for transparency or international rules on undersea tech might follow. After all, the stakes involved are higher in terms of keeping the internet flowing and power grids humming in an increasingly tense ocean.
