Photo/IllutrationA China Coast Guard vessel moves through Japanese territorial waters around the Tsushima Strait off the main island of Kyushu in July 2017. (Provided by the Japan Coast Guard)

Beijing's recent decision to transfer administrative control of its coast guard from civilian to military authority from July is causing headaches for Japan.

Given China's tradition of using the coast guard to patrol areas to which it lays territorial claims, the move is being viewed as worrying and possibly significant.

A sweeping government overhaul announced by Beijing last week means that the coast guard will become part of the People’s Armed Police Force, which is under the direct control of China’s Central Military Commission. This effectively puts President Xi Jinping in charge of the coast guard.

In recent years, China Coast Guard vessels have intruded at least a few times a month into Japanese territorial waters around the disputed Senkaku Islands in the East China Sea.

The incidents spiked sharply after a flare-up in the long simmering territorial row. China also claims the islands, which it calls Diaoyu Islands.

Tokyo and Beijing have sought to avoid a situation that leads to an unintended military clash.

The China Coast Guard was previously under the jurisdiction of the Ministry of Public Security.

The National People’s Congress, which approved the restructuring during a June 22 session, said the coast guard will “fulfill its law enforcement responsibility to maintain China’s maritime interests” with patrols to crack down on criminal activity and violations of maritime law, to conserve marine ecology and to manage fisheries.

It remains unclear, however, how its official authority will change under the reorganization.

China Coast Guard officials have explained to Japan and other neighboring countries whose territorial waters come close to overlapping that its role will remain unchanged for the time being.

Even so, the Japanese government expressed concern over the organizational change.

Defense Minister Itsunori Onodera noted at a June 26 news conference that Chinese vessels repeatedly intruding in waters around the Senkaku Islands belong to the China Coast Guard.

“We will maintain a level-headed response, but we are determined to steadfastly defend our country’s land mass, territorial waters and airspace,” he said.

The change in status follows the implementation June 8 of an air-maritime communication mechanism between Tokyo and Beijing that was first proposed more than a decade ago to avoid a contingency involving the Self-Defense Forces and the Chinese military.

When SDF aircraft and vessels come too close to their Chinese counterparts, they communicate with each other in English on a frequency agreed upon under the mechanism.

But a senior Defense Ministry official expressed doubts that the coast guard in its new role will be covered by the mechanism because it will not be a military force.

That could compound the difficulty facing Japan in how to respond in emergency situations if the functions and authority of the China Coast Guard are strengthened with its status remaining ambiguous, experts said.

(This article was written by Takashi Funakoshi in Beijing and Shinichi Fujiwara in Tokyo.)