China, Russia launch joint air patrol, alarms South Korea

China and Russia conducted a joint air patrol on June 6 over the Sea of Japan and East China Sea for a sixth time since 2019, prompting neighbouring South Korea and Japan to scramble fighter jets.

China's defence ministry said the patrol was part of the two militaries' annual cooperation plan. South Korea scrambled fighter jets, according to its military, after four Russian and four Chinese military aircraft entered its air defence zone in the south and east of the Korean peninsula, according to Reuters.

Japan's military said it had scrambled fighter jets after verifying that two Russian bombers had joined two Chinese bombers over the Sea of Japan and flown together as far as the East China Sea, where they were joined by two Chinese fighter planes.

In China's last joint aerial patrol with Russia in November, South Korea also scrambled fighter jets after Chinese H-6K bombers and Russian TU-95 bombers and SU-35 fighter jets entered its Air Defence Identification Zone (KADIZ).

Japan similarly scrambled jets when Chinese bombers and two Russian drones flew into the Sea of Japan.

An air defence zone is an area where countries demand that foreign aircraft take special steps to identify themselves. Unlike a country's airspace - the air above its territory and territorial waters - there are no international rules governing air defence zones.

The joint aerial patrols, which began before Russia sent its troops to Ukraine and Beijing and Moscow declared their "no-limits" partnership, are a result of long-expanding bilateral ties built partly on a mutual sense of threat from the United States and other military alliances.

In their May 2022 patrols, Chinese and Russian warplanes neared Japan's airspace as Tokyo hosted a Quad summit with the leaders of the United States, India and Australia, alarming Japan even though China said the flights were not directed at third parties.