Photo/Illutration The Japan Coast Guard’s Tsugaru patrol boat and three vessels from the Maritime Self-Defense Force, including the helicopter carrier Izumo on the right in the background, in a joint exercise in waters in the South China Sea on June 26. (Provided by the Japan Coast Guard)

The Japan Coast Guard and the Maritime Self-Defense Force conducted their first joint drill in the South China Sea on June 26, in a move apparently aimed at reining in China’s aggressive behavior in the region.

The exercise with the MSDF in foreign waters marked a rare assignment for the Coast Guard as it is usually tasked with patrolling Japan’s territorial waters.

The joint drill was the first the MSDF and Coast Guard has held overseas in at least five years. In recent years it has become increasingly apparent that the two entities need to coordinate more closely to share information.

The helicopter carrier Izumo, two other MSDF destroyers, and the Tsugaru, a Coast Guard patrol boat, participated in the drill in waters off Brunei. The Izumo is planned to be converted into an aircraft carrier equipped with fighter jets.

China has built a string of military outposts in the South China Sea to bolster its foothold in the waters, where it is locked in disputes with several countries over its sweeping territorial claims of islands, reefs and rocks.

Experts say the South China Sea drill is partly designed to discourage China from becoming more assertive in the region.

Coast Guard vessels patrol waters around the Senkaku Islands in the East China Sea to respond to vessels from China’s Coast Guard that routinely enter the contiguous zone and Japanese territorial waters there.

The islets, which are administered by Japan as part of Okinawa Prefecture, but are also claimed by China, have long been a source of a territorial dispute between the two countries.

Some defense experts say the Chinese Coast Guard ships that have appeared near the Senkakus have been assisted by People’s Liberation Army’s naval vessels.

“We cannot deal with the situation (around the Senkakus) unless Japan’s Coast Guard and the MSDF cooperate with each other extensively,” said a Japanese government official, referring to the significance of the exercise.

In the exercise, a helicopter took off from Izumo’s 248-meter-long deck, and headed for the Tsugaru, several kilometers away after the start of the joint exercise was announced.

After the chopper landed on the Tsugaru, its crew members had direct communications with Coast Guard members aboard the ship and confirmed their communication signals.

The Izumo has been out to sea since the end of April to conduct extended exercises in the South China Sea and the Indian Ocean.

The Tsugaru left Japan earlier this month for an anti-piracy training program in the South China Sea and joint exercises with maritime security authorities in Southeast Asian countries.

In China, an organizational shakeup in July last year put its Coast Guard into a unit under the control of the Central Military Commission, and raised concerns that the Coast Guard had been turned into a presence closely affiliated with the Chinese military.

Incursions by Chinese vessels into waters near the Senkakus are occurring more frequently.

Such ships entered the contiguous zone around the islets for a record 64 straight days between April and June.

Earlier this month, the Chinese Navy aircraft carrier Liaoning sailed south between Okinawa Prefecture’s main island and Miyakojima, an island located southwest of it in the prefecture, to reach the Pacific Ocean.

(This article was written by Yoshitaka Ito and Shun Niekawa.)