Chinese and Russian navies' Tsugaru Strait transit highlights growing defense ties

The Chinese and Russian militaries have sent a flotilla of 10 warships through the narrow Tsugaru Strait in northern Japan for the first time, in a signal of the two countries’ growing defense cooperation and an apparent response to a landmark nuclear submarine deal between the U.S., Britain and Australia.

The military vessels sailed through the narrow strait separating Japan’s main island and Hokkaido on Monday, the Defense Ministry said Tuesday.

It was the first time the ministry had confirmed a joint sailing by the two countries’ militaries through the waterway, which connects the Sea of Japan and the Pacific Ocean.

“The government is watching the activities of Chinese and Russian naval vessels around Japan with great interest,” Deputy Chief Cabinet Secretary Yoshihiko Isozaki said during a news conference Tuesday.

The Tsugaru Strait — which at its narrowest point is just 18.7 kilometers wide — is unusual in that Japan’s territorial waters extend just 3 nautical miles (5.6 km) into the waterway, instead of the usual 12 nautical miles, reportedly as a workaround to allow nuclear-armed U.S. Navy warships and submarines to transit the area without violating Japan’s prohibition against bringing nuclear weapons into its territory. Anywhere outside the 3 nautical miles is considered international waters open to foreign ships, including military vessels.

The Defense Ministry said that the Chinese and Russian ships did not enter Japan’s territorial waters.

Russia and China held joint naval drills further to the north, in the Sea of Japan, from Thursday through Sunday, and it was possible that some of the warships that passed through the strait had taken part in the exercise. Those drills marked the first time that the Chinese military had sent anti-submarine warfare aircraft and its largest destroyers for exercises abroad.

The passage through the Tsugaru Strait, however, could also be seen as a response by Beijing and Moscow to the stunning announcement last month of the AUKUS trilateral security pact between Washington, London and Canberra, under which the U.S. plans to sell a fleet of eight nuclear submarines to Australia.

Beijing has condemned the security deal, which analysts believe is intended as a counter to China’s growing military power in the region, saying that it risked “severely damaging regional peace … and intensifying an arms race.”

Moscow and Beijing have worked tirelessly to cultivate ever-closer military ties in recent years as both of their relations with the West have plummeted to fresh lows. In August, the two countries’ defense chiefs agreed to further bolster military cooperation, an announcement that came a day after senior officials from “Quad” nations — the U.S., Japan, India and Australia — held talks.

Although the Tsugaru Strait sailing has highlighted what Chinese experts called “the two sides’ high level of strategic mutual trust” amid the creation of “antagonistic” regional security groupings such as the Quad and AUKUS, analysts nonetheless say that anything beyond collaboration — let alone a formal alliance — is unlikely.

“We expect that the Sino-Russian relationship will continue to strengthen within the general framework of collaboration,” researchers from the Rand Corp. think tank wrote in an August report. “Still, a desire for independence and divergent political interests will lead China and Russia to avoid the risks that might emerge from closer cooperation, which will prevent them from seamlessly combining their power and more effectively challenging the United States.”

Staff writer Satoshi Sugiyama contributed to this report.