Recently, incidents of Chinese warships entering Japanese territorial waters without warning have been frequent, but the situation of Japanese warships sailing in Chinese territorial waters is extremely rare. In early July, a destroyer of the Japan Maritime Self-Defense Force (MSDF) entered Chinese territorial waters and conducted a brief voyage, causing attention. The Japanese Ministry of Defense is investigating this incident.
According to a report by Japan Broadcasting Corporation (NHK), on the morning of July 4, the JS Suzutsuki destroyer of the MSDF, sailing along the coast of Zhejiang Province in eastern China, briefly entered Chinese territorial waters without prior notification.
At that time, the Suzutsuki was on a mission to monitor a Chinese navy exercise in international waters. It stayed within about 12 nautical miles (22 kilometers) off the coast of Zhejiang for approximately 20 minutes. Following the urging of Chinese maritime patrol vessels, the ship left the area. The Japanese Ministry of Defense stated that it is investigating the incident but declined to comment further.
According to Kyodo News, citing sources from the Chinese side, during informal talks between China and Japan, a Japanese official pointed out that this violation may have been a “procedural error.”
China states that the destroyer did not immediately cease its passage in Chinese territorial waters despite receiving warnings from Chinese vessels. Chinese authorities suspect that this incident was a “deliberate provocation” by the Japanese destroyer and have been collecting and analyzing relevant information.
On the other hand, the Japanese government insists that the entry of the Suzutsuki into Chinese territorial waters was not unlawful, citing the Innocent Passage provision under international law.
Chinese navy warships have previously entered Japanese territorial waters without warning. The most recent incident was on September 16 last year when the Japanese Ministry of Defense reported that a Chinese navy survey vessel had entered Japanese territorial waters near Yakushima, Kagoshima Prefecture, and sailed within the waters for about an hour and a half. It was noted that this was the 12th violation of Japanese territorial waters by Chinese navy warships in the past three months, and the Japanese government has lodged a protest through diplomatic channels.
According to international law, as long as it does not threaten the peace, order, and security of the coastal state, ships of all nations can generally pass through the territorial waters of another country swiftly and continuously. Under the United Nations Convention on the Law of the Sea adopted in 1958 and 1982, all countries and all ships enjoy the right of innocent passage.
However, unlike civilian vessels, the right of innocent passage for warships can be controversial. In fact, some countries require foreign warships to obtain permission or provide notification before passing through their territorial waters.