On 1 November, at 7:50 PM local time, the Japanese Ministry of Defense detected a Chinese Type 636 survey vessel in the vicinity of the uninhabited island of Gajajima which lies about 170 kilometers South of Japan’s home islands. The vessel then proceeded North towards the larger island of Kuchinoerabujima which lies around 80 kilometers South of the home islands. At 12:10 AM on 2 November, the vessel entered Japanese territorial waters; the ship subsequently left Japan’s territorial waters south of the island about 3 hours later.
This intrusion marks the eighth time a PRC military vessel has been detected in Japanese waters since 2004. More worryingly, this is the fifth intrusion since October 2021 and the fourth this year.
China had previously defended its intrusions by claiming they are nothing more than innocent passages under UN Convention on the Law of the Sea (UNCLOS), which is somewhat ironic considering China’s stance towards Western Freedom of Navigation Operations in the international waters of the South China Sea and Taiwan Strait). Ignoring the fact that it is common practice to inform owners of territorial waters of transiting warships, this poses an interesting legal question under international law. On one hand, if the Chinese vessel was actively gathering intelligence, its passage clearly was not “innocent” under UNCLOS. However, if It really was just traveling, there is a case to be made that the passage was innocent.
The deep waters of the area have led to speculation that the PRC is trying to gather navigation intelligence for submarine operation. The path of the Chinese survey vessel was also not particularly efficient form the perspective of simply passing from point A to B. Nevertheless, whether intelligence was being gathered or not is not something that can be easily and definitively proven.
China has also previously argued that the Tokara Strait in which Gajajima is located is an international strait for the purpose of international law and navigation; the PRC holds that there is a right to transit passage through international straits independent of innocent passage. Japan denies this and does not recognize Tokara Strait as an international strait.
The recent incidents come at a time when China’s military is being more assertive beyond its shores. Recent months and years have seen significant Chinese encroachments in the South China Sea, more contestation of the Senkaku Islands (disputed between Japan and China), and intensified military flights and exercises near Taiwan.