A Chinese naval intelligence ship entered Japanese territorial waters off Kagoshima Prefecture on June 15, just six days after Tokyo filed a strong protest over the entry of a Chinese naval frigate into Japan's contiguous zone near the disputed Senkaku Islands.

Coincidence? We think not.

These incidents clearly signal China’s intention to achieve its aims while ignoring the security concerns of neighboring countries.

The Chinese government contends that passage of the warship through Japanese territorial waters was legal under freedom of navigation laws. China's Defense Ministry argues that the Tokara Strait south of Yakushima island in southern Japan is “a strait within territorial waters used for international navigation.”

“The Chinese warship’s passage was based on the principle of freedom of navigation that is stipulated under the United Nations Convention on the Law of the Sea,” a Chinese defense official said.

If the Tokara Strait is actually an international strait, as Beijing contends, it is, to be sure, open to the passage of foreign vessels, including warships, even though it lies in Japanese territorial waters.

But it is hard to believe that the Chinese spy ship was simply passing through the strait minding its own business. What was it actually doing?

The Chinese ship entered Japanese territorial waters shadowing Indian warships that were participating in an exercise involving Japan, the United States and India. The Chinese vessel may have been monitoring the Indian ships.

The Chinese government has not offered a clear or specific explanation for the warship's presence. It has only said the ship was engaged in “a drill in the open sea.”

It was the second time for a Chinese warship to enter Japanese territorial waters since a nuclear-powered submarine was sighted around the Sakishima islands in Okinawa Prefecture in November 2004.

The submarine violated international law by entering Japanese territorial waters submerged. At that time, the Chinese government admitted that the vessel had strayed into Japanese territory by mistake.

During the 12 years since then, China has aggressively beefed up its Navy and become increasingly assertive in expanding its naval presence.

China has used its naval muscle to stake out a position without holding any talks with the countries concerned, and then tried to justify its behavior by interpreting international law in a way that suits its purpose.

If Beijing continues acting this way, tensions in both the East China Sea and the South China Sea will keep growing.

If China really respects the principles of the United Nations Convention on the Law of the Sea, how does it explain its moves to unilaterally draw up a demarcation line called the “nine-dash line” to claim the major part of the South China Sea and forcefully reclaim reefs in disputed areas?

How can it justify its refusal to respect the ruling that the international Permanent Court of Arbitration is expected to hand down soon over the validity of China’s claim based on the line in response to a case filed by the Philippines?

The foreign ministers of the Association of Southeast Asian Nations expressed concern about the situation in the South China Sea during a June 14 meeting with their Chinese counterpart in China’s Yunnan Province.

China apparently wanted to highlight its close ties with ASEAN in the special foreign ministers’ meeting, but, not surprisingly, the outcome was the opposite of what was intended.

China is one of the world's leading countries, and it should take responsibility for peace in Asia.

But China has at times ignored the rules and norms of the global community and at other times used them to justify its dubious actions. The way China has been behaving has made it impossible for its neighbors to trust it.

China is not only disturbing the tranquility of the high seas, it is also treating principles of international law as if they were at its disposal. We are deeply concerned about China’s attitude.

--The Asahi Shimbun, June 17