Introduction | The shocking truth: The "lifeline of the internet" is beginning to be damaged in unexpected ways.
What comes to mind when you hear the term "submarine cable"? Certainly, you might imagine it as "internet relay equipment." However, its true nature is far more significant.
In recent years, the number of submarine cable damage incidents around the world has been rapidly increasing. This is not merely a simple equipment malfunction; it has emerged as a new challenge in today's society, where geopolitical risks are on the rise, in order to protect the "lifelines" of international communications.
This article details the current submarine cable crisis as of 2026 and explains why countermeasures are necessary now. It also introduces cutting-edge technologies and efforts to strengthen legal frameworks.
Why damage to undersea cables can be a "national security issue"
Let's start with the core facts.The international communication 99% is carried by submarine cables.Therefore, if this is disrupted, it will have a devastating impact on information flow and business activities worldwide.
A typical example is the incident that occurred off the coast of Taiwan in February 2026. A Togolese vessel, operated by a Chinese captain, dropped anchor, damaging an underwater cable connecting Taiwan and the Penghu Islands. As a result, Taiwan's Coast Guard Administration declared it a "national security-level incident."
Based on past cases, the causes of damage are diverse:
- Contact and abrasion caused by ship anchoring and fishing gear.
- Natural disasters (earthquakes, tsunamis, etc.)
- Unexpected malfunction
As statistics show, with 150 to 200 incidents of damage occurring annually, this is a frequent occurrence. Even more serious is,The heightened geopolitical tensions have increased concerns about intentional destruction.is.
Moves to strengthen protection are progressing in both technological and legal aspects.
So, how can we protect submarine cables? The answer lies in two pillars: "technological innovation" and "establishment of legal systems." There are already pioneering examples around the world, and Japan is rapidly catching up.
Point 1: Successful demonstration of "multicore fiber," the world's first submarine cable monitoring technology.
KDDI Research Institute and Amrit Corporation jointly succeeded in conducting the world's first demonstration in September 2025. Conventional cables only have one "core" which is the path for optical signals, but this technology secures multiple cores.In addition to increased transmission capacity, remote monitoring and diagnosis have become possible.That's right.
structure:Using optical signals, it can "rapidly identify" the location and cause of damage in cables spanning over 10,000 km. Google has announced plans to use it in submarine cables connecting Asia and North America in 2023, and widespread adoption is expected around 2030.
Point 2: Strengthening of legal systems in various countries and regions
Technical measures alone are insufficient. "There are limits to physical defenses," KDDI Research Institute points out. Therefore, legal and regulatory reinforcements are also essential.
- Taiwan:December 2025 – Seven laws related to the protection of submarine cables were amended. These amendments included stricter penalties for damage and enhanced navigation regulations.
- Estonia:September 2025 – The country's parliamentary legal affairs committee is considering strengthening accountability for damage to underwater infrastructure.
- European Union (EU):February 2025 – Develop an action plan for cable protection.
- US:August 2025 – New regulations will be enacted to strengthen cable protection and infrastructure investment.
- Japan:November 2025 – The Ministry of Internal Affairs and Communications will establish an expert panel to consider measures to protect submarine cables.
Point 3: Why are cables in "high seas" not subject to Japanese jurisdiction?
There are some important legal points you should be aware of. Damage within territorial waters can be handled under domestic law,In international waters and within Japan's exclusive economic zone (EEZ), even if goods are landed in Japan, Japanese jurisdiction may not apply.This reflects the reality that there are limits to territorial expansion, making the development of a defense system through international cooperation essential.
Supplemental Information | Submarine cables are designed to be redundant, but widespread damage poses a significant risk.
Submarine cables have a mechanism in place that ensures communication is not interrupted even if a section is broken, by providing multiple alternative routes. However,This is not intended to account for widespread, simultaneous damage.。
How will this change in terms of "work ethic"?
- Executives of companies using cloud and AI services should re-examine the vulnerabilities in their supply chains.
- Investors should increase their interest not only in infrastructure stocks but also in stocks related to submarine cable protection technology.
- Governments and local authorities should manage the "physical and geopolitical risks" of telecommunications infrastructure on a regular basis.
Technical supplementary information (concise version)
What is a multicore fiber?Unlike conventional cables, which only have one optical signal path, this cable improves transmission capacity and fault tolerance by adding multiple cores.
ICPC (International Cable Protection Committee):This is a world-leading organization that collects and analyzes statistical data on submarine cable damage, recording 150 to 200 incidents annually.
Summary | Who will the "maritime arteries" protect in the age of geopolitical risk?
The reason why submarine cables are starting to get damaged is the surge in data demand due to the spread of AI and cloud services. As a result, the total length of cables is increasing, but the risks are also relatively higher.
While "natural disasters and accidents make up the majority," particular attention should be paid to the growing "concerns about intentional destruction due to geopolitical tensions." In Japan, the possibility of power line disruption during an emergency is still only in the planning stages, but suspicions of man-made disconnections are increasing worldwide.
Advancing technological innovation and strengthening legal systems are now the key challenges in protecting the infrastructure that underpins global society. Submarine cables are not merely communication equipment; they are the very "main arteries of the sea" that support modern civilization.
In this sense, we are beginning to face the risk that the internet we use every day could come to a complete halt in an instant. This is an era in which we cannot ignore this issue, both as a matter of corporate supply chains and as a matter of international relations.
