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Japan: New Lord of the Subsea?

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Tokyo Report | Security | East Asia

Japan: New Lord of the Subsea?

As threats to the global web of subsea fiber-optic cables become more prominent, Japan has an opportunity to become a leader in submarine cable laying, repair, and security.

Japan: New Lord of the Subsea?

The Japan Maritime Self-Defense Force’s cable-laying ship, JS Muroto,

Credit: Ministry of Defense, Japan

Earlier this year, Taiwan experienced two significant submarine cable cuts that resulted in internet outages and other connectivity concerns. The Taiwan-Matsu No. 2 and No. 3 cables were likely severed by a Chinese fishing trawler and a Chinese cargo vessel accidentally, but it is still uncertain. The Japanese-manufactured cables are noteworthy because they connect Taiwan to its Matsu Islands, close to mainland China.

This year’s outage was part of a larger pattern where Taiwan has experienced 27 submarine internet cables cuts in the past five years. But it also came at a moment where China has begun to bureaucratically delay or take control over the laying of legitimate cables across the South China Sea with onerous local permitting processes, including most recently with the SJC2 line that will connect Japan to Taiwan, Hong Kong, and Singapore.

As tensions rise across East Asia and law of the sea issues become more salient, this latest series of submarine cable cleavages and bureaucratic maneuvers by China should come as a wake-up call for Japan and other nations across the region. Certainly, the vast majority of fiber-optic cable breaks are tied to earthquakes, dredging, fishing trawlers, or ship anchors, since most of the cables are only about the width of a garden-hose. (Sharks have also been documented gnawing through undersea cables.)

This latest round of submarine cable events, however, falls into a larger global pattern of growing security challenges tied to these subsea information highways from Europe to Asia.

The estimated 550 undersea fiber-optic cables that line the world’s ocean floors are responsible for transmitting more than 95 percent of voice and data traffic. This also amounts to around $10 trillion in financial transactions each day. Anything that disrupts the information and financial flows across these oceanic networks can have significant spillover effects.

Japan in particular is a crucial node along this larger web of subsea fiber-optic cables that run across the Pacific Ocean, connecting to such vital areas as Taiwan and other countries across Southeast Asia. Japan currently hosts 20 international landing stations, including 10 that link to other locations across Asia and eight that connect directly to the west coast of the United States.

Prime Minister Kishida Fumio has recognized the growing threat posed to Japan’s subsea internet cables. His government recently established a fund estimated at $440 million (50 billion yen) that will urge companies to establish more stations along its eastern Pacific Ocean coastlines and outside of Tokyo’s urban sprawl. The initiative similarly aims to build more data centers in outlying areas that have experienced significant population losses as an attempt to boost these regional economies.

This is certainly a step in the right direction, but Japan also has an opportunity to become more of a regional and global leader in submarine cable laying, repair, and security.

To begin, Japanese firms are frequently ranked as some of the world’s largest submarine cable manufacturers. The top cable producer is the U.S. firm SUBCOM, while some of the other top manufacturers are the Nippon Electric Company (NEC) subsidiary Ocean Cable and Communication (OCC); Nokia’s Alcatel Submarine Network; and Fujitsu. These top four firms account for around 90 percent of global cable production; Chinese-based Hengtong Optic-Electric Co. – an optical firm that acquired Huawei’s submarine cable division in 2020 – holds most of the remaining 10 percent of the market.

At present, Japan also has four to six repair and cable-laying ships, compared with China, which currently owns at least two. The telecommunications firms Nippon Telegraph and Telephone and KDDI own or charter two or three each, while the Japan Maritime Self-Defense Force (JMSDF) reportedly owns one such ship, the JS Muroto.

With Kishida’s recent announcement to double Japan’s defense budget over the next five years to 2 percent of Japan’s GDP, his cabinet has an opportunity to advocate for further investments in the country’s submarine cable laying and repair industry, in addition to expanding the Japan Coast Guard (JCG) and JMSDF platforms and assets that can support and defend both Japanese and regional the submarine cyber cable networks.

Yet in order to effectively improve upon these capabilities, the JCG and JMSDF must first reinforce their commitment to a more comprehensive maritime security approach that equally focuses on the highly valued subsea regions. The Japan Air Self-Defense Force’s decision to rebrand as the Aerospace Self-Defense Force to demonstrate a stronger emphasis on space domain awareness could serve as an example. One retired JMSDF admiral also recently proposed to similarly change the current Japanese term for “maritime” from kaijo, which denotes the ocean surface, to kaiyo, a word more closely aligned with its English translation. The same could be applied to the JCG (Kaijo-hoancho).

The importance of the undersea domain awareness is seemingly not lost on Japan’s defense establishment. The activities of JMSDF’s cable-laying ship, JS Muroto, are rarely publicized, and JMSDF members are reportedly tight-lipped about the ship’s operations, owing to their highly classified nature. Yet every year, the JS Muroto conducts cable-laying exercises with the U.S. Navy at its base in Guam, a promising sign of awareness between the two allies of the necessity to defend these networks.

Aside from a hard security angle, a ripe opportunity also exists for Japan’s government to tie further subsea investments into its larger Free and Open Indo-Pacific initiative, which aims to promote increased multilayered connectivity and economic prosperity across the region. Japan has already demonstrated its leadership and ability to support several island nations under duress following a major natural disaster, as well as nations that simply seek to upgrade their submarine cables and broader access to faster internet connections and the 5G network.

Most recently in Tonga, Japan helped to support the repair of 56 miles of a subsea internet cable that had ruptured following a 7.6 magnitude earthquake. Japan also worked with Australia and the United States to finance and lay the Palau Spur Cable in the Indian Ocean, the first trilateral infrastructure project of its kind.

Beyond the Pacific Islands, other countries have similarly expressed a preference to work with Japan over other entities. Chile, for example, opted to reject a Chinese proposal in favor of the one offered by Japan for the first submarine fiber-optic cable between South America and the Indo-Pacific. Japan could indeed emerge as a viable alternative to the construction of new cross-regional cable networks.

Although Taiwan’s recent submarine cable breaks are a good impetus for bolstering Japan’s investments in its cable-laying, repair, and security apparatus, the future stability and health of the global political economy lies beneath the seas and is increasingly at risk, especially as China becomes more assertive in the maritime domain. Japan is well positioned to be a world leader that can manufacture, repair, and protect these highly valuable submarine cables across the global commons and in an Indo-Pacific way.

Guest Author

Geoffrey F. Gresh

Geoffrey F. Gresh is professor of International Relations at National Defense University in Washington, D.C., and the author most recently of “To Rule Eurasia’s Waves: The New Great Power Competition at Sea.” The views expressed here are the authors alone and do not represent their respective institutions.

Guest Author

Hotaka Nakamura

Hotaka Nakamura is the interim associate director of Faculty Affairs at Georgetown University’s Walsh School of Foreign Service. The views expressed here are the authors alone and do not represent their respective institutions.