China, Russia step up probe of Japan's aerial, maritime surveillance systems

Paths taken by Chinese and Russian aircraft and ships around Japan in February 2025. (Japan MoD/Janes)

China and Russia increased their deployments of intelligence-gathering vessels and aircraft around Japan in early February, and this appears to be a co-ordinated probe into Tokyo's aerial and maritime surveillance capabilities.

Information released by the Japanese Ministry of Defense's (MoD's) Joint Staff Office over several days in February indicates that these deployments include repeated sorties of a Russian Vishnya (Project 864)-class auxiliary, general intelligence (AGI) ship within Japan's archipelagic waters.

This began on 1 February when the AGI ship Kareliya , which was operating in the East China Sea, changed its course for the Japanese archipelago and sailed through waters of the Okinawa Islands.

Kareliya subsequently made its way into the waters of Japan's Amami Archipelago off Kikaijima Island on 4 February, read a statement released by the Joint Staff Office on 11 February.

It then sailed past the southern end of Japan's Kyushu Island during 7 and 8 February before going through the Osumi Strait on 9 February while heading back to the East China Sea where it was last detected on 11 February, the statement added.

At around the same time that Kareliya was sailing near the Osumi Strait, the People's Liberation Army Navy (PLAN) Dongdiao (Type 815/815A)-class AGI Yuhengxing carried out a southward transit to the Pacific Ocean.

This transit saw the ship sail through the waters between Okinawa Island and Miyako Island while it headed towards the Southern Pacific from the East China Sea.

Yuhengxing's