 China and Russia conducted a joint air patrol on June 7 over the Sea of Japan and East China Sea for a sixth time since 2019. The joint aerial patrols, which began before Russia sent its troops in 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. China's Defense Ministry said the patrol was part of the two military's annual cooperation plan. South Korea scrambled fighter jets, according to its military, after four Russian and four Chinese military aircraft entered its air defense zone in the south and east of the Korean peninsula.