Gas Fields in East China Sea: Japan Must Not Get Used to China’s Self-righteousness

Editorial

15:45 JST, January 22, 2026

It is obvious that China’s unilateral pursuit of gas field development in the East China Sea violates the agreement between Japan and China. The Japanese government needs to tenaciously urge Beijing to keep the international agreement.

In January, it was confirmed that China was building a new structure, believed to be a facility for gas field development, on the western side near the Japan-China median line in the East China Sea. It was also revealed that a drilling vessel in the vicinity has had its legs extended to the seabed to be anchored.

China built four structures in the gas fields — including the fields known as “Shirakaba” and “Kashi” in Japan — without permission from Japan about 20 years ago. It was pointed out that the gas fields could be connected underground to the Japanese side, potentially siphoning off Japan’s resources.

For that reason, the Japanese and Chinese governments negotiated and agreed in 2008 to conduct joint development in certain areas straddling the median line and to continue negotiations toward expanding joint development.

However, since then, China has not agreed to hold further talks and the joint development has not been realized. Under such circumstances, China’s self-righteous behavior of unilaterally advancing development is unacceptable. It is quite natural that the Japanese government protested against China.

Fundamentally, the exclusive economic zones and the continental shelves in the East China Sea — which would establish the right to develop seabed resources — have not yet been delimited between Japan and China.

Japan maintains that the boundary should be the median line equidistant from both countries’ coasts. China, however, claims that its continental shelf extends to the Okinawa Trough, closer to the Japanese side than the median line, and the two sides remain at odds on the issue.

All the structures in the gas fields are located on the Chinese side of the Japan-China median line. Yet this does not justify China’s unilateral development in the disputed waters.

As if anticipating Japan’s inability to take effective measures to deal with the issue, China has continued developing gas fields over the past two decades. The newly discovered structure, if completed, will be the 22nd such facility.

China’s vessels also repeatedly intrude into Japan’s territorial waters around the Senkaku Islands, over which Beijing unilaterally claims sovereignty.

It is China’s usual practice to accumulate faits accomplis to try to alter the status quo in its favor.

The Japanese government must not take these Chinese tactics lightly. It should protest each instance of self-righteous behavior. The Japanese side should consider countermeasures, with a view to its own development as well. Strengthening warning and surveillance systems in the East China Sea is indispensable.

There is concern that if public interest in territorial integrity and maritime interests wanes, China could take advantage of such a situation and escalate its actions. The Japanese government needs to intensify its awareness-raising activities.

(From The Yomiuri Shimbun, Jan. 22, 2026)