A Chinese spy ship conducted a monthlong voyage that saw it sail around Japan’s main islands as the United States ally held a large-scale military drill to bolster its defenses.
The Chinese Foreign Ministry did not immediately respond to a request for comment.
Why It Matters
China, which Japan views as a major threat, is expanding its military presence across the western Pacific Ocean through deployments of its navy—the world’s largest by number of vessels—including missions that transited international straits near Japan.
Last month, Japan conducted a military exercise involving its air, ground and maritime branches across the country’s main and outlying islands, as well as surrounding waters and airspace. The war game included a variety of training, including anti-ship drills.
Under a U.S. containment strategy, Japan is part of the First Island Chain, along with Taiwan and the Philippines, intended to project allied military power to deter and defend against potential Chinese aggression over Taiwan and disputed regional waters.
What To Know
Japan’s Defense Ministry reported that a Chinese naval intelligence-collection ship was tracked sailing westward through the Osumi Strait, south of the main island of Kyushu, on Tuesday, as it moved from the broader western Pacific Ocean to the East China Sea.
The Chinese vessel was identified by its hull number as the Type 815A spy ship CNS Kaiyangxing. This class of ship has often been deployed to monitor and gather intelligence on foreign military exercises, a pattern noted by the Pentagon in an assessment report.
The Japan Maritime Self-Defense Force was mobilized to monitor the Chinese spy ship, which did not enter Tokyo’s territorial waters—typically extending 13.8 miles from the coastline—during its transit, according to a map provided by Japan’s Defense Ministry.
The Kaiyangxing first approached Japan on September 28-29 as it passed through the Tsushima Strait, between the Japanese archipelago and the Korean Peninsula, from the East China Sea to the Sea of Japan, also known in South Korea as the East Sea.
The Chinese vessel continued its northeastward voyage until it reached the western end of the Tsugaru Strait, between Japan’s main islands of Hokkaido and Honshu, where it passed east through the waterway toward the broader western Pacific on October 4.
It was unclear how far the spy ship operated from Japan after exiting the channel. Last month, the Chinese coast guard transited the Tsugaru Strait, where Japan’s territorial waters extend 3.4 miles from the coasts, allowing passage through international waters.
The Osumi Strait transit also indicates that the Kaiyangxing sailed around three of Japan’s four main islands—Honshu, Shikoku and Kyushu—excluding Hokkaido. Three Chinese naval vessels completed a voyage around all four islands in early October.
What People Are Saying
Japan’s defense white paper 2025 read: “China has been intensifying its activities across the entire region surrounding Japan, including in the East China Sea, particularly in the area around the Senkaku Islands, the Sea of Japan, and the western Pacific Ocean, extending beyond the so-called the [sic] first island chain to the second island chain.”
The Pentagon’s Chinese military power report 2024 assessed: “…In recent years, the [People’s Liberation Army] has begun conducting the same types of military activities inside and outside the [First Island Chain] in the [Exclusive Economic Zones] of other countries…Examples include sending intelligence collection ships to collect on military exercises.”
What Happens Next
It remains to be seen how Tokyo will further strengthen its defenses as China is expected to continue military activities across the western Pacific, particularly near Japan.