Japan is set to review its undersea cable supply chains to assess potential exposure to Chinese components, following similar actions by the United States. The Japanese government plans to conduct a survey within the current fiscal year, which ends in March 2026, to determine whether domestic companies involved in the installation and maintenance of submarine cables procure critical parts from China
This move aligns with the U.S. Federal Communications Commission’s (FCC) recent announcement to prohibit the use of Chinese technology in undersea telecommunications cables connecting to the United States. The FCC’s decision aims to mitigate national security risks associated with potential espionage and cyber threats from foreign adversaries, particularly China
Japan’s investigation will focus on companies like NEC, Sumitomo Electric Industries, and NTT, which play significant roles in the country’s undersea cable infrastructure. The government is considering support measures, including increasing domestic production capacity and providing subsidies to facilitate the acquisition of specialized cable-laying vessels, which can cost over ¥10 billion (approximately €67 million)
The concern over Chinese involvement in undersea cable infrastructure has been heightened by recent incidents. In 2023, a Chinese-made eavesdropping device was found near Okinawa, and between late 2024 and early 2025, several cases of damage were reported around Taiwan and in the Baltic Sea, leading to suspicions of sabotage by China and Russia
Japan’s reliance on undersea cables for 99% of its international communications makes any disruptions a significant concern, particularly for sectors like finance. Unlike the United States, which authorized the involvement of the armed forces in cable laying and maintenance operations in 2021, Japan has not yet established guidelines for cooperation with the Self-Defense Forces or the Coast Guard, nor has it developed specific contingency plans
In summary, Japan’s upcoming investigation into its undersea cable supply chains reflects growing concerns over national security and the need to ensure the integrity of critical infrastructure amid escalating geopolitical tensions.
