TOKYO - Chinese coast guard ships have started escorting the country's public vessels in Western Pacific waters where Japan and the Philippines' exclusive economic zones overlap, a data analysis found Sunday, in an apparent move to claim jurisdiction in the area near Taiwan.
The escort by two coast guard vessels for the government survey ship Xiang Yang Hong 22 for three days from June 16 off the southern coast of Japan's westernmost island of Yonaguni was Beijing's apparent response to a Tokyo-Manila agreement in May to launch bilateral maritime delimitation negotiations.
The analysis of data, collected from the "automatic identification system" to track vessels, was carried out by ingeniSPACE, a geospatial data analysis firm, and Aki Mouri, an associate professor for modern China studies at Doshisha University in Kyoto.
The sea area is near the eastern coast of Taiwan, a self-ruled democratic island which communist-led China regards as an inalienable part of its territory. It has not ruled out the use of force to take control of it.
According to the analysis, the three ships, after joining up in an area within Japan's EEZ, sailed back and forth in a north-south direction, with the coast guard vessels flanking the research ship.
The coast guard ships remained in the area of overlapping EEZs even after the survey vessel left the waters on June 18. Japan's government monitored the Chinese ships by deploying patrol ships and planes from its own coast guard.
The government also monitored China's coast guard escorting other public ships when the Chinese transport ministry was conducting maritime patrol activities from June 6 to 10 in a nearby area.
At their meeting in Tokyo in late May, Japanese Prime Minister Sanae Takaichi and Philippine President Ferdinand Marcos Jr. agreed to begin talks to delimit the maritime boundary of their nations' EEZs and the continental shelf between the two countries "in accordance with international law."
The agreement by the two U.S. allies has triggered a backlash from China, which has said that any negotiations on maritime delimitation in waters east of Taiwan must involve Beijing and continued its coast guard ships' navigation in the sea area.
Jun Tsuruta, a professor of international law at Meiji Gakuin University in Tokyo, said the situation in the area is escalating from a stage where China merely asserts its claims to one where it "takes concrete actions and builds a track record of its exercise of authority."
Stressing that conducting a survey in Japan's EEZ without its consent violates international law, Tsuruta said the announcement of maritime demarcation negotiations between Japan and the Philippines may have "provided a pretext for this shift."
Tokyo and Manila share concerns over Beijing's growing military assertiveness, with Chinese vessels clashing with Philippine ships near disputed shoals in the South China Sea and repeatedly entering waters around the Japan-controlled, China-claimed Senkaku Islands in the East China Sea.
Takaichi's parliamentary remarks in November suggesting an attack by China on Taiwan could prompt a response by the Japan Self-Defense Forces in support of the U.S. military have also refueled diplomatic tensions between the two East Asian neighbors.
