Back in December, the naval forces of China and Russia launched a one-week joint exercise off the coast of the Chinese Zhejiang Province in the East China Sea.

Source: https://english.almanar.com.lb/1808314

Chinese navy vessels traveling to the Pacific Ocean from the East China Sea often pass close to Miyakojima, which has hosted GSDF mobile anti-ship missile launchers since 2019.

Source: https://pragativadi.com/military-chopper-carrying-10-people-crashes-in-sea-in-japan-rescue-ops-underway/?utm_source=rss&utm_medium=rss&utm_campaign=military-chopper-carrying-10-people-crashes-in-sea-in-japan-rescue-ops-underway

Japan has territorial disputes with China over the Japanese-controlled East China Sea islands which Beijing also claims.

Source: https://www.sandiegouniontribune.com/news/nation-world/story/2023-12-18/us-indo-pacific-commander-is-very-concerned-about-escalation-of-china-russia-military-ties

Okinawa is an island south of mainland Japan where the East China Sea meets the Pacific Ocean.

Source: https://www.moneytalksnews.com/slideshows/okinawan-secrets-to-a-long-life/

The area is located in an area over the East China Sea slightly northeast of Taiwan that routinely sees heavy civilian air traffic.

Source: https://www.mutiny.in/china-launches-a-weather-satellite-and-flights-avoid-a-no-fly-zone-to-northern-taiwan/