The strategic future of subsea cables: Japan case study

Given its geography as an island nation, 99 percent of Japan’s communications depend on subsea cables. Perhaps as a natural consequence, Japan is a significant player in the subsea cable industry, both as a manufacturer and as a connectivity hub between North America and Asia. Japanese companies Nippon Telegraph and Telephone (NTT) and KDDI Corporation, for example, own cable-laying and repair ships, and the Nippon Electric Company (NEC) alone is one of the largest subsea cable builders in the world.

Japan is home to at least 20 international submarine cable landing stations that connect to the United States, Australia, South Korea, Southeast Asia, Russia, and the Mediterranean. These cables are primarily located off the cities of Minamiboso in Chiba Prefecture and Shima in Mie Prefecture. Other cables are located off the northernmost and southernmost main islands of Hokkaido and Kyushu (Figure 1). Most cable landing stations also connect to Internet exchanges in Tokyo or Osaka, where more than 80 percent of the country’s data centers are concentrated.

In 2022, then–Prime Minister Fumio Kishida recognized the vulnerabilities of Japan’s subsea internet cables and established a $440 million fund to incentivize companies to build more stations along the Pacific Ocean coastlines and near Tokyo. The initiative also included a push to construct data centers in rural areas that have been impacted by demographic issues as an attempt to boost these regional economies. In addition, Japan’s Ministry of Economy, Trade, and Industry (METI) and Ministry of Internal Affairs and Communications (MIC) have designated the cable industry as a national security priority and “are looking to support capital investment to boost production and installation of cables.”

Read more at Center for Strategic and International Studies